Hi critical thinkers!
Two days have been allocated at your disposal. Tuesday from 14-16 and Wednesday at 10-11am. Please do come for a chat if there is any topic you did not understand well or for a piece of advice.
Nassor
Friday, May 29, 2009
Tuesday, May 26, 2009
TEST FOR PR STUDENTS
Hi critical thinkers!
We shall have our test as agreed at 13.00 hrs tomorrow. Lets meet at the notice board at 12.50pm and see which room is empty for your use.
Good luck!
We shall have our test as agreed at 13.00 hrs tomorrow. Lets meet at the notice board at 12.50pm and see which room is empty for your use.
Good luck!
FALLACIES
Fallacies are statements that might sound reasonable or superficially true but are actually flawed or dishonest.
When readers detect them, these logical fallacies backfire by making the audience think the writer is (a) unintelligent or (b) deceptive.
It is important to avoid them in your own arguments, and it is also important to be able to spot them in others' arguments so a false line of reasoning won't fool you.
Think of this as intellectual kung-fu: the art of self-defense in a debate. For extra impact, learn both the Latin terms and the English equivalents.
FALLACIES OF RELEVANCE: These fallacies appeal to evidence or examples that are not relevant to the argument at hand.
Appeal to Force (Argumentum Ad Baculum or the "Might-Makes-Right" Fallacy): This argument uses force, the threat of force, or some other unpleasant backlash to make the audience accept a conclusion. It commonly appears as a last resort when evidence or rational arguments fail to convince a reader. If the debate is about whether or not 2+2=4, an opponent's argument that he will smash your nose in if you don't agree with his claim doesn't change the truth of an issue.
Logically, this consideration has nothing to do with the points under consideration. The fallacy is not limited to threats of violence, however. The fallacy includes threats of any unpleasant backlash--financial, professional, and so on. Example: "Superintendent, you should cut the school budget by $16,000. I need not remind you that past school boards have fired superintendents who cannot keep down costs."
While intimidation may force the superintendent to conform, it does not convince him that the choice to cut the budget was the most beneficial for the school or community.
Lobbyists use this method when they remind legislators that they represent so many thousand votes in the legislators' constituencies and threaten to throw the politician out of office if he doesn't vote the way they want. Teachers use this method if they state that students should hold the same political or philosophical position as the teachers or risk failing the class.
Note that it is isn't a logical fallacy, however, to assert that students must fulfill certain requirements in the course or risk failing the class!
Genetic Fallacy: The genetic fallacy is the claim that an idea, product, or person must be untrustworthy because of its racial, geographic, or ethnic origin. "That car can't possibly be any good! It was made in Japan!" Or, "Why should I listen to her argument? She comes from California, and we all know those people are flakes." Or, "Ha! I'm not reading that book. It was published in Tennessee, and we know all Tennessee folk are hillbillies and rednecks!" This type of fallacy is closely related to the fallacy of argumentum ad hominem or personal attack, appearing immediately below.
Personal Attack (Argumentum Ad Hominem, literally, "argument toward the man." Also called "Poisoning the Well"): Attacking or praising the people who make an argument, rather than discussing the argument itself. This practice is fallacious because the personal character of an individual is logically irrelevant to the truth or falseness of the argument itself. The statement "2+2=4" is true regardless if is stated by criminals, congressmen, or pastors. There are two subcategories:
(1) Abusive: To argue that proposals, assertions, or arguments must be false or dangerous because they originate with atheists, Christians, Communists, capitalists, the John Birch Society, Catholics, anti-Catholics, racists, anti-racists, feminists, misogynists (or any other group) is fallacious. This persuasion comes from irrational psychological transference rather than from an appeal to evidence or logic concerning the issue at hand. This is similar to the genetic fallacy, and only an anti-intellectual would argue otherwise.
(2) Circumstantial: To argue that an opponent should accept an argument because of circumstances in his or her life. If one's adversary is a clergyman, suggesting that he should accept a particular argument because not to do so would be incompatible with the scriptures is such a fallacy. To argue that, because the reader is a Republican or Democrat, she must vote for a specific measure is likewise a circumstantial fallacy. The opponent's special circumstances have no control over the truth of a specific contention. This is also similar to the genetic fallacy in some ways. If you are a college student who wants to learn rational thought, you simply must avoid circumstantial fallacies.
Argumentum ad Populum (Literally "Argument to the People): Using an appeal to popular assent, often by arousing the feelings and enthusiasm of the multitude rather than building an argument. It is a favorite device with the propagandist, the demagogue, and the advertiser. An example of this type of argument is Shakespeare's version of Mark Antony's funeral oration for Julius Caesar. There are three basic approaches:
(1) Bandwagon Approach: “Everybody is doing it.” This argumentum ad populum asserts that, since the majority of people believes an argument or chooses a particular course of action, the argument must be true, or the course of action must be followed, or the decision must be the best choice. For instance, “85% of consumers purchase IBM computers rather than Macintosh; all those people can’t be wrong. IBM must make the best computers.” Popular acceptance of any argument does not prove it to be valid, nor does popular use of any product necessarily prove it is the best one. After all, 85% of people may once have thought planet earth was flat, but that majority's belief didn't mean the earth really was flat when they believed it! Keep this in mind, and remember that everybody should avoid this type of logical fallacy.
(2) Patriotic Approach: "Draping oneself in the flag." This argument asserts that a certain stance is true or correct because it is somehow patriotic, and that those who disagree are unpatriotic. It overlaps with pathos and argumentum ad hominem to a certain extent. The best way to spot it is to look for emotionally charged terms like Americanism, rugged individualism, motherhood, patriotism, godless communism, etc. A true American would never use this approach. And a truly free man will exercise his American right to drink beer, since beer belongs in this great country of ours.
(3) Snob Approach: This type of argumentum ad populum doesn’t assert “everybody is doing it,” but rather that “all the best people are doing it.” For instance, “Any true intellectual would recognize the necessity for studying logical fallacies.” The implication is that anyone who fails to recognize the truth of the author’s assertion is not an intellectual, and thus the reader had best recognize that necessity.
In all three of these examples, the rhetorician does not supply evidence that an argument is true; he merely makes assertions about people who agree or disagree with the argument.
Appeal to Tradition (Argumentum Ad Traditio): This line of thought asserts that a premise must be true because people have always believed it or done it. Alternatively, it may conclude that the premise has always worked in the past and will thus always work in the future: “Jefferson City has kept its urban growth boundary at six miles for the past thirty years. That has been good enough for thirty years, so why should we change it now? If it ain’t broke, don’t fix it.” Such an argument is appealing in that it seems to be common sense, but it ignores important questions. Might an alternative policy work even better than the old one? Are there drawbacks to that long-standing policy? Are circumstances changing from the way they were thirty years ago?
Appeal to Improper Authority (Argumentum Ad Verecundium, literally "argument from that which is improper"): An appeal to an improper authority, such as a famous person or a source that may not be reliable. This fallacy attempts to capitalize upon feelings of respect or familiarity with a famous individual. It is not fallacious to refer to an admitted authority if the individual’s expertise is within a strict field of knowledge. On the other hand, to cite Einstein to settle an argument about education or economics is fallacious. To cite Darwin, an authority on biology, on religious matters is fallacious. To cite Cardinal Spellman on legal problems is fallacious. The worst offenders usually involve movie stars and psychic hotlines.
A subcategory is the Appeal to Biased Authority. In this sort of appeal, the authority is one who actually is knowledgeable on the matter, but one who may have professional or personal motivations that render his professional judgment suspect: for instance, "To determine whether fraternities are beneficial to this campus, we interviewed all the frat presidents." Or again, "To find out whether or not sludge-mining really is endangering the Tuskogee salamander's breeding grounds, we interviewed the supervisors of the sludge-mines, who declared there is no problem."
Indeed, it is important to get "both viewpoints" on an argument, but basing a substantial part of your argument on a source that has personal, professional, or financial interests at stake may lead to biased arguments.
Appeal to Emotion (Argumentum Ad Misericordiam, literally, "argument from pity"): An emotional appeal concerning what should be a logical issue during a debate. While pathos generally works to reinforce a reader’s sense of duty or outrage at some abuse, if a writer tries to use emotion merely for the sake of getting the reader to accept what should be a logical conclusion, the argument is a fallacy. For example, in the 1880s, prosecutors in a Virginia court presented overwhelming proof that a boy was guilty of murdering his parents with an ax. The defense presented a "not-guilty" plea for on the grounds that the boy was now an orphan, with no one to look after his interests if the court was not lenient. This appeal to emotion obviously seems misplaced, and the argument is irrelevant to the question of whether or not he did the crime.
COMPONENT FALLACIES: Component fallacies are errors in inductive and deductive reasoning or in syllogistic terms that fail to overlap.
Begging the Question (also called Petitio Principii, this term is sometimes used interchangeably with Circular Reasoning): If writers assume as evidence for their argument the very conclusion they are attempting to prove, they engage in the fallacy of begging the question. The most common form of this fallacy is when the first claim is initially loaded with the very conclusion one has yet to prove. For instance, suppose a particular student group states, "Useless courses like English 101 should be dropped from the college's curriculum." The members of the student group then immediately move on in the argument, illustrating that spending money on a useless course is something nobody wants. Yes, we all agree that spending money on useless courses is a bad thing. However, those students never did prove that English 101 was itself a useless course--they merely "begged the question" and moved on to the next "safe" part of the argument, skipping over the part that's the real controversy, the heart of the matter, the most important component. Begging the question if often hidden in the form of a complex question (see below).
Circular Reasoning is closely related to begging the question. Often the writers using this fallacy word take one idea and phrase it in two statements. The assertions differ sufficiently to obscure the fact that that the same proposition occurs as both a premise and a conclusion. The speaker or author then tries to "prove" his or her assertion by merely repeating it in different words. Richard Whately wrote in Elements of Logic (London 1826): “To allow every man unbounded freedom of speech must always be on the whole, advantageous to the state; for it is highly conducive to the interest of the community that each individual should enjoy a liberty perfectly unlimited of expressing his sentiments.” Obviously the premise is not logically irrelevant to the conclusion, for if the premise is true the conclusion must also be true. It is, however, logically irrelevant in proving the conclusion.
In the example, the author is repeating the same point in different words, and then a ttempting to "prove" the first assertion with the second one. A more complex but equally fallacious type of circular reasoning is to create a circular chain of reasoning like this one: "God exists." "How do you know that God exists?" "The Holy Book says so." "Why should I believe the Holy Book?" "Because it's the inspired word of God."
Hasty Generalization (Dicto Simpliciter, also called “Jumping to Conclusions,” "Converse Accident"): Mistaken use of inductive reasoning when there are too few samples to prove a point. Example: "Susan failed Biology 101. Herman failed Biology 101. Egbert failed Biology 101. I therefore conclude that most students who take Biology 101 will fail it." In understanding and characterizing general situations, a logician cannot normally examine every single example.
However, the examples used in inductive reasoning should be typical of the problem or situation at hand. Maybe Susan, Herman, and Egbert are exceptionally poor students. Maybe they were sick and missed too many lectures that term to pass. If a logician wants to make the case that most students will fail Biology 101, she should (a) get a very large sample--at least one larger than three-or (b) if that isn't possible, she will need to go out of his way to prove to the reader that her three samples are somehow representative of the norm. If a logician considers only exceptional or dramatic cases and generalizes a rule that fits these alone, the author commits the fallacy of hasty generalization.
One common type of hasty generalization is the Fallacy of Accident. This error occurs when one applies a general rule to a particular case when accidental circumstances render the general rule inapplicable. For example, in Plato’s Republic, Plato finds an exception to the general rule that one should return what one has borrowed: “Suppose that a friend when in his right mind has deposited arms with me and asks for them when he is not in his right mind. Ought I to give the weapons back to him? No one would say that I ought or that I should be right in doing so. . . .” What is true in general may not be true universally and without qualification. So remember, generalizations are bad. All of them. Every single last one. Except, of course, for those that are not.
Another common example of this fallacy is the misleading statistic. Suppose an individual argues that women must be incompetent drivers, and he points out that last Tuesday at the Department of Motor Vehicles, 50% of the women who took the driving test failed. That would seem to be compelling evidence from the way the statistic is set forth. However, if only two women took the test that day, the results would be far less clear-cut. Incidentally, the cartoon Dilbert makes much of an incompetent manager who cannot perceive misleading statistics. He does a statistical study of when employees call in sick and cannot come to work during the five-day work week. He becomes furious to learn that 40% of office "sick-days" occur on Mondays (20%) and Fridays (20%)--just in time to create a three-day weekend. Suspecting fraud, he decides to punish his workers. The irony, of course, is that these two days compose 40% of a five day work week, so the numbers are completely average. Similar nonsense emerges when parents or teachers complain that "50% of students perform at or below the national average on standardized tests in mathematics and verbal aptitude." Of course they do! The very nature of an average implies that!
False Cause: This fallacy establishes a cause/effect relationship that does not exist. There are various Latin names for various analyses of the fallacy. The two most common include these types:
(1) Non Causa Pro Causa (Literally, "Not the cause for a cause"): A general, catch-all category for mistaking a false cause of an event for the real cause.
(2) Post Hoc, Ergo Propter Hoc (Literally: "After this, therefore because of this"): This type of false cause occurs when the writer mistakenly assumes that, because the first event preceded the second event, it must mean the first event caused the later one. Sometimes it does, but sometimes it doesn't. It is the honest writer's job to establish clearly that connection rather than merely assert it exists. Example: "A black cat crossed my path at noon. An hour later, my mother had a heart-attack. Because the first event occurred earlier, it must have caused the bad luck later." This is how superstitions begin.
The most common examples are arguments that viewing a particular movie or show, or listening to a particular type of music “caused” the listener to perform an antisocial act--to snort coke, shoot classmates, or take up a life of crime. These may be potential suspects for the cause, but the mere fact that an individual did these acts and subsequently behaved in a certain way does not yet conclusively rule out other causes. Perhaps the listener had an abusive home-life or school-life, suffered from a chemical imbalance leading to depression and paranoia, or made a bad choice in his companions. Other potential causes must be examined before asserting that only one event or circumstance alone earlier in time caused a event or behavior later. For more information, see correlation and causation.
Irrelevant Conclusion (Ignorantio Elenchi): This fallacy occurs when a rhetorician adapts an argument purporting to establish a particular conclusion and directs it to prove a different conclusion. For example, when a particular proposal for housing legislation is under consideration, a legislator may argue that decent housing for all people is desirable. Everyone, presumably, will agree. However, the question at hand concerns a particular measure. The question really isn't, "Is it good to have decent housing?" The question really is, "Will this particular measure actually provide it or is there a better alternative?" This type of fallacy is a common one in student papers when students use a shared assumption--such as the fact that decent housing is a desirable thing to have--and then spend the bulk of their essays focused on that fact rather than the real question at issue. It's similar to begging the question, above.
One of the most common forms of Ignorantio Elenchi is the "Red Herring." A red herring is a deliberate attempt to change the subject or divert the argument from the real question at issue to some side-point; for instance, “Senator Jones should not be held accountable for cheating on his income tax. After all, there are other senators who have done far worse things.” Another example: “I should not pay a fine for reckless driving. There are many other people on the street who are dangerous criminals and rapists, and the police should be chasing them, not harassing a decent tax-paying citizen like me.” Certainly, worse criminals do exist, but that it is another issue! The questions at hand are (1) did the speaker drive recklessly and (2) should he pay a fine for it?
Another similar example of the red herring is the fallacy known as Tu Quoque (Latin for "And you too!"), which asserts that the advice or argument must be false simply because the person presenting the advice doesn't follow it herself. For instance, "Reverend Jeremias claims that theft is wrong, but how can theft be wrong if Jeremias himself admits he stole objects when he was a child?"
Straw Man Argument: A subtype of the red herring, this fallacy includes any lame attempt to "prove" an argument by overstating, exaggerating, or over-simplifying the arguments of the opposing side. Such an approach is building a straw man argument. The name comes from the idea of a boxer or fighter who meticulously fashions a false opponent out of straw, like a scarecrow, and then easily knocks it over in the ring before his admiring audience. His "victory" is a hollow mockery, of course, because the straw-stuffed opponent is incapable of fighting back. When a writer makes a cartoon-like caricature of the opposing argument, ignoring the real or subtle points of contention, and then proceeds to knock down each "fake" point one-by-one, he has created a straw man argument.
For instance, one speaker might be engaged in a debate concerning welfare. The opponent argues, "Tennessee should increase funding to unemployed single mothers during the first year after childbirth because they need sufficient money to provide medical care for their newborn children." The second speaker retorts, "My opponent believes that some parasites who don't work should get a free ride from the tax money of hard-working honest citizens. I'll show you why he's wrong . . ." In this example, the second speaker is engaging in a straw man strategy, distorting the opposition's statement about medical care for newborn children into an oversimplified form so he can more easily appear to "win." However, the second speaker is only defeating a dummy-argument rather than honestly engaging in the real nuances of the debate.
Non Sequitur (literally, "It does not follow"): A non sequitur is any argument that does not follow from the previous statements. Usually what happened is that the writer leaped from A to B and then jumped to D, leaving out step C of an argument she thought through in her head, but did not put down on paper. The phrase is applicable in general to any type of logical fallacy, but logicians use the term particularly in reference to syllogistic errors such as the undistributed middle term, non causa pro causa, and ignorantio elenchi. A common example would be an argument along these lines: "Giving up our nuclear arsenal in the 1980's weakened the United States' military. Giving up nuclear weaponry also weakened China in the 1990s. For this reason, it is wrong to try to outlaw pistols and rifles in the United States today." There's obviously a step or two missing here.
The "Slippery Slope" Fallacy (also called "The Camel's Nose Fallacy") is a non sequitur in which the speaker argues that, once the first step is undertaken, a second or third step will inevitably follow, much like the way one step on a slippery incline will cause a person to fall and slide all the way to the bottom. It is also called "the Camel's Nose Fallacy" because of the image of a sheik who let his camel stick its nose into his tent on a cold night. The idea is that the sheik is afraid to let the camel stick its nose into the tent because once the beast sticks in its nose, it will inevitably stick in its head, and then its neck, and eventually its whole body. However, this sort of thinking does not allow for any possibility of stopping the process. It simply assumes that, once the nose is in, the rest must follow--that the sheik can't stop the progression once it has begun--and thus the argument is a logical fallacy. For instance, if one were to argue, "If we allow the government to infringe upon our right to privacy on the Internet, it will then feel free to infringe upon our privacy on the telephone. After that, FBI agents will be reading our mail. Then they will be placing cameras in our houses. We must not let any governmental agency interfere with our Internet communications, or privacy will completely vanish in the United States." Such thinking is fallacious; no logical proof has been provided yet that infringement in one area will necessarily lead to infringement in another, no more than a person buying a single can of Coca-Cola in a grocery store would indicate the person will inevitably go on to buy every item available in the store, helpless to stop herself. So remember to avoid the slippery slope fallacy; once you use one, you may find yourself using more and more logical fallacies.
Either/Or Fallacy (also called "the Black-and-White Fallacy" and "False Dilemma"): This fallacy occurs when a writer builds an argument upon the assumption that there are only two choices or possible outcomes when actually there are several. Outcomes are seldom so simple. This fallacy most frequently appears in connection to sweeping generalizations: “Either we must ban X or the American way of life will collapse.” "We go to war with Canada, or else Canada will eventually grow in population and overwhelm the United States." "Either you drink Burpsy Cola, or you will have no friends and no social life." Either you must avoid either/or fallacies, or everyone will think you are foolish.
Faulty Analogy: Relying only on comparisons to prove a point rather than arguing deductively and inductively. For example, “education is like cake; a small amount tastes sweet, but eat too much and your teeth will rot out. Likewise, more than two years of education is bad for a student.” The analogy is only acceptable to the degree a reader thinks that education is similar to cake. As you can see, faulty analogies are like flimsy wood, and just as no carpenter would build a house out of flimsy wood, no writer should ever construct an argument out of flimsy material.
FALLACIES OF AMBIGUITY: These errors occur with ambiguous words or phrases, the meanings of which shift and change in the course of discussion. Such more or less subtle changes can render arguments fallacious.
Equivocation: Using a word in a different way than the author used it in the original premise, or changing definitions halfway through a discussion. When we use the same word or phrase in different senses within one line of argument, we commit the fallacy of equivocation. Consider this example: “Plato says the end of a thing is its perfection; I say that death is the end of life; hence, death is the perfection of life.” Here the word end means "goal" in Plato's usage, but it means "last event" or "termination" in the author's second usage. Clearly, the speaker is twisting Plato's meaning of the word to draw a very different conclusion. Compare with amphiboly, below.
Amphiboly (from the Greek word "indeterminate"): This fallacy is similar to equivocation. Here, the ambiguity results from grammatical construction. A statement may be true according to one interpretation of how each word functions in a sentence and false according to another. When a premise works with an interpretation that is true, but the conclusion uses the secondary "false" interpretation, we have the fallacy of amphiboly on our hands. In the command, "Save soap and waste paper," the amphibolous use of "waste" results in the problem of determining whether "waste" functions as a verb or as an adjective.
Composition: This fallacy is a result of reasoning from the properties of the parts of the whole to the properties of the whole itself--it is an inductive error. Such an argument might hold that, because every individual part of a large tractor is lightweight, the entire machine also must be lightweight. This fallacy is similar to Hasty Generalization (see above), but it focuses on parts of a single whole rather than using too few examples to create a categorical generalization.
Also compare it with Division (see below).
Division: This fallacy is the reverse of composition. It is the misapplication of deductive reasoning. One fallacy of division argues falsely that what is true of the whole must be true of individual parts. Such an argument notes that, "Microtech is a company with great influence in the California legislature. Egbert Smith works at Microtech. He must have great influence in the California legislature." This is not necessarily true. Egbert might work as a graveyard shift security guard or as the copy-machine repairman at Microtech--positions requiring little interaction with the California legislature. Another fallacy of division attributes the properties of the whole to the individual member of the whole: "Sunsurf is a company that sells environmentally safe products. Susan Jones is a worker at Sunsurf. She must be an environmentally minded individual." (Perhaps she is motivated by money alone?)
FALLACIES OF OMISSION: These errors occur because the logician leaves out necessary material in an argument or misdirects others from missing information.
Stacking the Deck: In this fallacy, the speaker "stacks the deck" in her favor by ignoring examples that disprove the point, and listing only those examples that support her case. This fallacy is closely related to hasty generalization, but the term usually implies deliberate deception rather than an accidental logical error. Contrast it with the straw man argument.
Argument from the Negative: Arguing from the negative asserts that, since one position is untenable, the opposite stance must be true. This fallacy is often used interchangeably with Argumentum Ad Ignorantium (listed below) and the either/or fallacy (listed above). For instance, one might mistakenly argue that, since the Newtonian theory of mathematics is not one hundred percent accurate, Einstein’s theory of relativity must be true. Perhaps not. Perhaps the theories of quantum mechanics are more accurate, and Einstein’s theory is flawed. Perhaps they are all wrong. Disproving an opponent’s argument does not necessarily mean your own argument must be true automatically, no more than disproving your opponent's assertion that 2+2=5 would automatically mean your argument that 2+2=7 must be the correct one.
Appeal to a Lack of Evidence (Argumentum Ad Ignorantium, literally "Argument from Ignorance"): Appealing to a lack of information to prove a point, or arguing that, since the opposition cannot disprove a claim, the opposite stance must be true. An example of such an argument is the assertion that ghosts must exist because no one has been able to prove that they do not exist. Logicians know this is a logical fallacy because no competing argument has yet revealed itself.
Hypothesis Contrary to Fact (Argumentum Ad Speculum): Trying to prove something in the real world by using imaginary examples alone, or asserting that, if hypothetically X had occurred, Y would have been the result. For instance, suppose an individual asserts that Einstein had been aborted in utero, the world would never have learned about relativity, or that if Monet had been trained as a butcher rather than going to college, the impressionistic movement would have never influenced modern art. Such hypotheses are misleading lines of argument because it is often possible that some other individual would have solved the relativistic equations or introduced an impressionistic art style. The speculation might make an interesting thought-experiment, but it is simply useless when it comes to actually proving anything about the real world. A common example is the idea that one "owes" her success to another individual who taught her. For instance, "You owe me part of your increased salary. If I hadn't taught you how to recognize logical fallacies, you would be flipping hamburgers at McDonald's for minimum wages right now instead of taking in hundreds of thousands of dollars as a lawyer." Perhaps. But perhaps the audience would have learned about logical fallacies elsewhere, so the hypothetical situation described is meaningless.
Complex Question (Also called the "Loaded Question"): Phrasing a question or statement in such as way as to imply another unproven statement is true without evidence or discussion. This fallacy often overlaps with begging the question (above), since it also presupposes a definite answer to a previous, unstated question. For instance, if I were to ask you “Have you stopped taking drugs yet?” my hidden supposition is that you have been taking drugs. Such a question cannot be answered with a simple yes or no answer. It is not a simple question but consists of several questions rolled into one. In this case the unstated question is, “Have you taken drugs in the past?” followed by, “If you have taken drugs in the past, have you stopped taking them now?” In cross-examination, a lawyer might ask a flustered witness, “Where did you hide the evidence?” or "when did you stop beating your wife?" The intelligent procedure when faced with such a question is to analyze its component parts. If one answers or discusses the prior, implicit question first, the explicit question may dissolve.
Complex questions appear in written argument frequently. A student might write, “Why is private development of resources so much more efficient than any public control?” The rhetorical question leads directly into his next argument. However, an observant reader may disagree, recognizing the prior, implicit question remains unaddressed. That question is, of course, whether private development of resources really is more efficient in all cases, a point which the author is skipping entirely and merely assuming to be true without discussion.
Contradictory Premises: Establishing a premise in such a way that it contradicts another, earlier premise. For instance, "If God can do anything, he can make a stone so heavy that he can't lift it." The first premise establishes a deity that has the irresistible capacity to move other objects. The second premise establishes an immovable object impervious to any movement. If the first object capable of moving anything exists, by definition, the immovable object cannot exist, and vice-versa.
When readers detect them, these logical fallacies backfire by making the audience think the writer is (a) unintelligent or (b) deceptive.
It is important to avoid them in your own arguments, and it is also important to be able to spot them in others' arguments so a false line of reasoning won't fool you.
Think of this as intellectual kung-fu: the art of self-defense in a debate. For extra impact, learn both the Latin terms and the English equivalents.
FALLACIES OF RELEVANCE: These fallacies appeal to evidence or examples that are not relevant to the argument at hand.
Appeal to Force (Argumentum Ad Baculum or the "Might-Makes-Right" Fallacy): This argument uses force, the threat of force, or some other unpleasant backlash to make the audience accept a conclusion. It commonly appears as a last resort when evidence or rational arguments fail to convince a reader. If the debate is about whether or not 2+2=4, an opponent's argument that he will smash your nose in if you don't agree with his claim doesn't change the truth of an issue.
Logically, this consideration has nothing to do with the points under consideration. The fallacy is not limited to threats of violence, however. The fallacy includes threats of any unpleasant backlash--financial, professional, and so on. Example: "Superintendent, you should cut the school budget by $16,000. I need not remind you that past school boards have fired superintendents who cannot keep down costs."
While intimidation may force the superintendent to conform, it does not convince him that the choice to cut the budget was the most beneficial for the school or community.
Lobbyists use this method when they remind legislators that they represent so many thousand votes in the legislators' constituencies and threaten to throw the politician out of office if he doesn't vote the way they want. Teachers use this method if they state that students should hold the same political or philosophical position as the teachers or risk failing the class.
Note that it is isn't a logical fallacy, however, to assert that students must fulfill certain requirements in the course or risk failing the class!
Genetic Fallacy: The genetic fallacy is the claim that an idea, product, or person must be untrustworthy because of its racial, geographic, or ethnic origin. "That car can't possibly be any good! It was made in Japan!" Or, "Why should I listen to her argument? She comes from California, and we all know those people are flakes." Or, "Ha! I'm not reading that book. It was published in Tennessee, and we know all Tennessee folk are hillbillies and rednecks!" This type of fallacy is closely related to the fallacy of argumentum ad hominem or personal attack, appearing immediately below.
Personal Attack (Argumentum Ad Hominem, literally, "argument toward the man." Also called "Poisoning the Well"): Attacking or praising the people who make an argument, rather than discussing the argument itself. This practice is fallacious because the personal character of an individual is logically irrelevant to the truth or falseness of the argument itself. The statement "2+2=4" is true regardless if is stated by criminals, congressmen, or pastors. There are two subcategories:
(1) Abusive: To argue that proposals, assertions, or arguments must be false or dangerous because they originate with atheists, Christians, Communists, capitalists, the John Birch Society, Catholics, anti-Catholics, racists, anti-racists, feminists, misogynists (or any other group) is fallacious. This persuasion comes from irrational psychological transference rather than from an appeal to evidence or logic concerning the issue at hand. This is similar to the genetic fallacy, and only an anti-intellectual would argue otherwise.
(2) Circumstantial: To argue that an opponent should accept an argument because of circumstances in his or her life. If one's adversary is a clergyman, suggesting that he should accept a particular argument because not to do so would be incompatible with the scriptures is such a fallacy. To argue that, because the reader is a Republican or Democrat, she must vote for a specific measure is likewise a circumstantial fallacy. The opponent's special circumstances have no control over the truth of a specific contention. This is also similar to the genetic fallacy in some ways. If you are a college student who wants to learn rational thought, you simply must avoid circumstantial fallacies.
Argumentum ad Populum (Literally "Argument to the People): Using an appeal to popular assent, often by arousing the feelings and enthusiasm of the multitude rather than building an argument. It is a favorite device with the propagandist, the demagogue, and the advertiser. An example of this type of argument is Shakespeare's version of Mark Antony's funeral oration for Julius Caesar. There are three basic approaches:
(1) Bandwagon Approach: “Everybody is doing it.” This argumentum ad populum asserts that, since the majority of people believes an argument or chooses a particular course of action, the argument must be true, or the course of action must be followed, or the decision must be the best choice. For instance, “85% of consumers purchase IBM computers rather than Macintosh; all those people can’t be wrong. IBM must make the best computers.” Popular acceptance of any argument does not prove it to be valid, nor does popular use of any product necessarily prove it is the best one. After all, 85% of people may once have thought planet earth was flat, but that majority's belief didn't mean the earth really was flat when they believed it! Keep this in mind, and remember that everybody should avoid this type of logical fallacy.
(2) Patriotic Approach: "Draping oneself in the flag." This argument asserts that a certain stance is true or correct because it is somehow patriotic, and that those who disagree are unpatriotic. It overlaps with pathos and argumentum ad hominem to a certain extent. The best way to spot it is to look for emotionally charged terms like Americanism, rugged individualism, motherhood, patriotism, godless communism, etc. A true American would never use this approach. And a truly free man will exercise his American right to drink beer, since beer belongs in this great country of ours.
(3) Snob Approach: This type of argumentum ad populum doesn’t assert “everybody is doing it,” but rather that “all the best people are doing it.” For instance, “Any true intellectual would recognize the necessity for studying logical fallacies.” The implication is that anyone who fails to recognize the truth of the author’s assertion is not an intellectual, and thus the reader had best recognize that necessity.
In all three of these examples, the rhetorician does not supply evidence that an argument is true; he merely makes assertions about people who agree or disagree with the argument.
Appeal to Tradition (Argumentum Ad Traditio): This line of thought asserts that a premise must be true because people have always believed it or done it. Alternatively, it may conclude that the premise has always worked in the past and will thus always work in the future: “Jefferson City has kept its urban growth boundary at six miles for the past thirty years. That has been good enough for thirty years, so why should we change it now? If it ain’t broke, don’t fix it.” Such an argument is appealing in that it seems to be common sense, but it ignores important questions. Might an alternative policy work even better than the old one? Are there drawbacks to that long-standing policy? Are circumstances changing from the way they were thirty years ago?
Appeal to Improper Authority (Argumentum Ad Verecundium, literally "argument from that which is improper"): An appeal to an improper authority, such as a famous person or a source that may not be reliable. This fallacy attempts to capitalize upon feelings of respect or familiarity with a famous individual. It is not fallacious to refer to an admitted authority if the individual’s expertise is within a strict field of knowledge. On the other hand, to cite Einstein to settle an argument about education or economics is fallacious. To cite Darwin, an authority on biology, on religious matters is fallacious. To cite Cardinal Spellman on legal problems is fallacious. The worst offenders usually involve movie stars and psychic hotlines.
A subcategory is the Appeal to Biased Authority. In this sort of appeal, the authority is one who actually is knowledgeable on the matter, but one who may have professional or personal motivations that render his professional judgment suspect: for instance, "To determine whether fraternities are beneficial to this campus, we interviewed all the frat presidents." Or again, "To find out whether or not sludge-mining really is endangering the Tuskogee salamander's breeding grounds, we interviewed the supervisors of the sludge-mines, who declared there is no problem."
Indeed, it is important to get "both viewpoints" on an argument, but basing a substantial part of your argument on a source that has personal, professional, or financial interests at stake may lead to biased arguments.
Appeal to Emotion (Argumentum Ad Misericordiam, literally, "argument from pity"): An emotional appeal concerning what should be a logical issue during a debate. While pathos generally works to reinforce a reader’s sense of duty or outrage at some abuse, if a writer tries to use emotion merely for the sake of getting the reader to accept what should be a logical conclusion, the argument is a fallacy. For example, in the 1880s, prosecutors in a Virginia court presented overwhelming proof that a boy was guilty of murdering his parents with an ax. The defense presented a "not-guilty" plea for on the grounds that the boy was now an orphan, with no one to look after his interests if the court was not lenient. This appeal to emotion obviously seems misplaced, and the argument is irrelevant to the question of whether or not he did the crime.
COMPONENT FALLACIES: Component fallacies are errors in inductive and deductive reasoning or in syllogistic terms that fail to overlap.
Begging the Question (also called Petitio Principii, this term is sometimes used interchangeably with Circular Reasoning): If writers assume as evidence for their argument the very conclusion they are attempting to prove, they engage in the fallacy of begging the question. The most common form of this fallacy is when the first claim is initially loaded with the very conclusion one has yet to prove. For instance, suppose a particular student group states, "Useless courses like English 101 should be dropped from the college's curriculum." The members of the student group then immediately move on in the argument, illustrating that spending money on a useless course is something nobody wants. Yes, we all agree that spending money on useless courses is a bad thing. However, those students never did prove that English 101 was itself a useless course--they merely "begged the question" and moved on to the next "safe" part of the argument, skipping over the part that's the real controversy, the heart of the matter, the most important component. Begging the question if often hidden in the form of a complex question (see below).
Circular Reasoning is closely related to begging the question. Often the writers using this fallacy word take one idea and phrase it in two statements. The assertions differ sufficiently to obscure the fact that that the same proposition occurs as both a premise and a conclusion. The speaker or author then tries to "prove" his or her assertion by merely repeating it in different words. Richard Whately wrote in Elements of Logic (London 1826): “To allow every man unbounded freedom of speech must always be on the whole, advantageous to the state; for it is highly conducive to the interest of the community that each individual should enjoy a liberty perfectly unlimited of expressing his sentiments.” Obviously the premise is not logically irrelevant to the conclusion, for if the premise is true the conclusion must also be true. It is, however, logically irrelevant in proving the conclusion.
In the example, the author is repeating the same point in different words, and then a ttempting to "prove" the first assertion with the second one. A more complex but equally fallacious type of circular reasoning is to create a circular chain of reasoning like this one: "God exists." "How do you know that God exists?" "The Holy Book says so." "Why should I believe the Holy Book?" "Because it's the inspired word of God."
Hasty Generalization (Dicto Simpliciter, also called “Jumping to Conclusions,” "Converse Accident"): Mistaken use of inductive reasoning when there are too few samples to prove a point. Example: "Susan failed Biology 101. Herman failed Biology 101. Egbert failed Biology 101. I therefore conclude that most students who take Biology 101 will fail it." In understanding and characterizing general situations, a logician cannot normally examine every single example.
However, the examples used in inductive reasoning should be typical of the problem or situation at hand. Maybe Susan, Herman, and Egbert are exceptionally poor students. Maybe they were sick and missed too many lectures that term to pass. If a logician wants to make the case that most students will fail Biology 101, she should (a) get a very large sample--at least one larger than three-or (b) if that isn't possible, she will need to go out of his way to prove to the reader that her three samples are somehow representative of the norm. If a logician considers only exceptional or dramatic cases and generalizes a rule that fits these alone, the author commits the fallacy of hasty generalization.
One common type of hasty generalization is the Fallacy of Accident. This error occurs when one applies a general rule to a particular case when accidental circumstances render the general rule inapplicable. For example, in Plato’s Republic, Plato finds an exception to the general rule that one should return what one has borrowed: “Suppose that a friend when in his right mind has deposited arms with me and asks for them when he is not in his right mind. Ought I to give the weapons back to him? No one would say that I ought or that I should be right in doing so. . . .” What is true in general may not be true universally and without qualification. So remember, generalizations are bad. All of them. Every single last one. Except, of course, for those that are not.
Another common example of this fallacy is the misleading statistic. Suppose an individual argues that women must be incompetent drivers, and he points out that last Tuesday at the Department of Motor Vehicles, 50% of the women who took the driving test failed. That would seem to be compelling evidence from the way the statistic is set forth. However, if only two women took the test that day, the results would be far less clear-cut. Incidentally, the cartoon Dilbert makes much of an incompetent manager who cannot perceive misleading statistics. He does a statistical study of when employees call in sick and cannot come to work during the five-day work week. He becomes furious to learn that 40% of office "sick-days" occur on Mondays (20%) and Fridays (20%)--just in time to create a three-day weekend. Suspecting fraud, he decides to punish his workers. The irony, of course, is that these two days compose 40% of a five day work week, so the numbers are completely average. Similar nonsense emerges when parents or teachers complain that "50% of students perform at or below the national average on standardized tests in mathematics and verbal aptitude." Of course they do! The very nature of an average implies that!
False Cause: This fallacy establishes a cause/effect relationship that does not exist. There are various Latin names for various analyses of the fallacy. The two most common include these types:
(1) Non Causa Pro Causa (Literally, "Not the cause for a cause"): A general, catch-all category for mistaking a false cause of an event for the real cause.
(2) Post Hoc, Ergo Propter Hoc (Literally: "After this, therefore because of this"): This type of false cause occurs when the writer mistakenly assumes that, because the first event preceded the second event, it must mean the first event caused the later one. Sometimes it does, but sometimes it doesn't. It is the honest writer's job to establish clearly that connection rather than merely assert it exists. Example: "A black cat crossed my path at noon. An hour later, my mother had a heart-attack. Because the first event occurred earlier, it must have caused the bad luck later." This is how superstitions begin.
The most common examples are arguments that viewing a particular movie or show, or listening to a particular type of music “caused” the listener to perform an antisocial act--to snort coke, shoot classmates, or take up a life of crime. These may be potential suspects for the cause, but the mere fact that an individual did these acts and subsequently behaved in a certain way does not yet conclusively rule out other causes. Perhaps the listener had an abusive home-life or school-life, suffered from a chemical imbalance leading to depression and paranoia, or made a bad choice in his companions. Other potential causes must be examined before asserting that only one event or circumstance alone earlier in time caused a event or behavior later. For more information, see correlation and causation.
Irrelevant Conclusion (Ignorantio Elenchi): This fallacy occurs when a rhetorician adapts an argument purporting to establish a particular conclusion and directs it to prove a different conclusion. For example, when a particular proposal for housing legislation is under consideration, a legislator may argue that decent housing for all people is desirable. Everyone, presumably, will agree. However, the question at hand concerns a particular measure. The question really isn't, "Is it good to have decent housing?" The question really is, "Will this particular measure actually provide it or is there a better alternative?" This type of fallacy is a common one in student papers when students use a shared assumption--such as the fact that decent housing is a desirable thing to have--and then spend the bulk of their essays focused on that fact rather than the real question at issue. It's similar to begging the question, above.
One of the most common forms of Ignorantio Elenchi is the "Red Herring." A red herring is a deliberate attempt to change the subject or divert the argument from the real question at issue to some side-point; for instance, “Senator Jones should not be held accountable for cheating on his income tax. After all, there are other senators who have done far worse things.” Another example: “I should not pay a fine for reckless driving. There are many other people on the street who are dangerous criminals and rapists, and the police should be chasing them, not harassing a decent tax-paying citizen like me.” Certainly, worse criminals do exist, but that it is another issue! The questions at hand are (1) did the speaker drive recklessly and (2) should he pay a fine for it?
Another similar example of the red herring is the fallacy known as Tu Quoque (Latin for "And you too!"), which asserts that the advice or argument must be false simply because the person presenting the advice doesn't follow it herself. For instance, "Reverend Jeremias claims that theft is wrong, but how can theft be wrong if Jeremias himself admits he stole objects when he was a child?"
Straw Man Argument: A subtype of the red herring, this fallacy includes any lame attempt to "prove" an argument by overstating, exaggerating, or over-simplifying the arguments of the opposing side. Such an approach is building a straw man argument. The name comes from the idea of a boxer or fighter who meticulously fashions a false opponent out of straw, like a scarecrow, and then easily knocks it over in the ring before his admiring audience. His "victory" is a hollow mockery, of course, because the straw-stuffed opponent is incapable of fighting back. When a writer makes a cartoon-like caricature of the opposing argument, ignoring the real or subtle points of contention, and then proceeds to knock down each "fake" point one-by-one, he has created a straw man argument.
For instance, one speaker might be engaged in a debate concerning welfare. The opponent argues, "Tennessee should increase funding to unemployed single mothers during the first year after childbirth because they need sufficient money to provide medical care for their newborn children." The second speaker retorts, "My opponent believes that some parasites who don't work should get a free ride from the tax money of hard-working honest citizens. I'll show you why he's wrong . . ." In this example, the second speaker is engaging in a straw man strategy, distorting the opposition's statement about medical care for newborn children into an oversimplified form so he can more easily appear to "win." However, the second speaker is only defeating a dummy-argument rather than honestly engaging in the real nuances of the debate.
Non Sequitur (literally, "It does not follow"): A non sequitur is any argument that does not follow from the previous statements. Usually what happened is that the writer leaped from A to B and then jumped to D, leaving out step C of an argument she thought through in her head, but did not put down on paper. The phrase is applicable in general to any type of logical fallacy, but logicians use the term particularly in reference to syllogistic errors such as the undistributed middle term, non causa pro causa, and ignorantio elenchi. A common example would be an argument along these lines: "Giving up our nuclear arsenal in the 1980's weakened the United States' military. Giving up nuclear weaponry also weakened China in the 1990s. For this reason, it is wrong to try to outlaw pistols and rifles in the United States today." There's obviously a step or two missing here.
The "Slippery Slope" Fallacy (also called "The Camel's Nose Fallacy") is a non sequitur in which the speaker argues that, once the first step is undertaken, a second or third step will inevitably follow, much like the way one step on a slippery incline will cause a person to fall and slide all the way to the bottom. It is also called "the Camel's Nose Fallacy" because of the image of a sheik who let his camel stick its nose into his tent on a cold night. The idea is that the sheik is afraid to let the camel stick its nose into the tent because once the beast sticks in its nose, it will inevitably stick in its head, and then its neck, and eventually its whole body. However, this sort of thinking does not allow for any possibility of stopping the process. It simply assumes that, once the nose is in, the rest must follow--that the sheik can't stop the progression once it has begun--and thus the argument is a logical fallacy. For instance, if one were to argue, "If we allow the government to infringe upon our right to privacy on the Internet, it will then feel free to infringe upon our privacy on the telephone. After that, FBI agents will be reading our mail. Then they will be placing cameras in our houses. We must not let any governmental agency interfere with our Internet communications, or privacy will completely vanish in the United States." Such thinking is fallacious; no logical proof has been provided yet that infringement in one area will necessarily lead to infringement in another, no more than a person buying a single can of Coca-Cola in a grocery store would indicate the person will inevitably go on to buy every item available in the store, helpless to stop herself. So remember to avoid the slippery slope fallacy; once you use one, you may find yourself using more and more logical fallacies.
Either/Or Fallacy (also called "the Black-and-White Fallacy" and "False Dilemma"): This fallacy occurs when a writer builds an argument upon the assumption that there are only two choices or possible outcomes when actually there are several. Outcomes are seldom so simple. This fallacy most frequently appears in connection to sweeping generalizations: “Either we must ban X or the American way of life will collapse.” "We go to war with Canada, or else Canada will eventually grow in population and overwhelm the United States." "Either you drink Burpsy Cola, or you will have no friends and no social life." Either you must avoid either/or fallacies, or everyone will think you are foolish.
Faulty Analogy: Relying only on comparisons to prove a point rather than arguing deductively and inductively. For example, “education is like cake; a small amount tastes sweet, but eat too much and your teeth will rot out. Likewise, more than two years of education is bad for a student.” The analogy is only acceptable to the degree a reader thinks that education is similar to cake. As you can see, faulty analogies are like flimsy wood, and just as no carpenter would build a house out of flimsy wood, no writer should ever construct an argument out of flimsy material.
FALLACIES OF AMBIGUITY: These errors occur with ambiguous words or phrases, the meanings of which shift and change in the course of discussion. Such more or less subtle changes can render arguments fallacious.
Equivocation: Using a word in a different way than the author used it in the original premise, or changing definitions halfway through a discussion. When we use the same word or phrase in different senses within one line of argument, we commit the fallacy of equivocation. Consider this example: “Plato says the end of a thing is its perfection; I say that death is the end of life; hence, death is the perfection of life.” Here the word end means "goal" in Plato's usage, but it means "last event" or "termination" in the author's second usage. Clearly, the speaker is twisting Plato's meaning of the word to draw a very different conclusion. Compare with amphiboly, below.
Amphiboly (from the Greek word "indeterminate"): This fallacy is similar to equivocation. Here, the ambiguity results from grammatical construction. A statement may be true according to one interpretation of how each word functions in a sentence and false according to another. When a premise works with an interpretation that is true, but the conclusion uses the secondary "false" interpretation, we have the fallacy of amphiboly on our hands. In the command, "Save soap and waste paper," the amphibolous use of "waste" results in the problem of determining whether "waste" functions as a verb or as an adjective.
Composition: This fallacy is a result of reasoning from the properties of the parts of the whole to the properties of the whole itself--it is an inductive error. Such an argument might hold that, because every individual part of a large tractor is lightweight, the entire machine also must be lightweight. This fallacy is similar to Hasty Generalization (see above), but it focuses on parts of a single whole rather than using too few examples to create a categorical generalization.
Also compare it with Division (see below).
Division: This fallacy is the reverse of composition. It is the misapplication of deductive reasoning. One fallacy of division argues falsely that what is true of the whole must be true of individual parts. Such an argument notes that, "Microtech is a company with great influence in the California legislature. Egbert Smith works at Microtech. He must have great influence in the California legislature." This is not necessarily true. Egbert might work as a graveyard shift security guard or as the copy-machine repairman at Microtech--positions requiring little interaction with the California legislature. Another fallacy of division attributes the properties of the whole to the individual member of the whole: "Sunsurf is a company that sells environmentally safe products. Susan Jones is a worker at Sunsurf. She must be an environmentally minded individual." (Perhaps she is motivated by money alone?)
FALLACIES OF OMISSION: These errors occur because the logician leaves out necessary material in an argument or misdirects others from missing information.
Stacking the Deck: In this fallacy, the speaker "stacks the deck" in her favor by ignoring examples that disprove the point, and listing only those examples that support her case. This fallacy is closely related to hasty generalization, but the term usually implies deliberate deception rather than an accidental logical error. Contrast it with the straw man argument.
Argument from the Negative: Arguing from the negative asserts that, since one position is untenable, the opposite stance must be true. This fallacy is often used interchangeably with Argumentum Ad Ignorantium (listed below) and the either/or fallacy (listed above). For instance, one might mistakenly argue that, since the Newtonian theory of mathematics is not one hundred percent accurate, Einstein’s theory of relativity must be true. Perhaps not. Perhaps the theories of quantum mechanics are more accurate, and Einstein’s theory is flawed. Perhaps they are all wrong. Disproving an opponent’s argument does not necessarily mean your own argument must be true automatically, no more than disproving your opponent's assertion that 2+2=5 would automatically mean your argument that 2+2=7 must be the correct one.
Appeal to a Lack of Evidence (Argumentum Ad Ignorantium, literally "Argument from Ignorance"): Appealing to a lack of information to prove a point, or arguing that, since the opposition cannot disprove a claim, the opposite stance must be true. An example of such an argument is the assertion that ghosts must exist because no one has been able to prove that they do not exist. Logicians know this is a logical fallacy because no competing argument has yet revealed itself.
Hypothesis Contrary to Fact (Argumentum Ad Speculum): Trying to prove something in the real world by using imaginary examples alone, or asserting that, if hypothetically X had occurred, Y would have been the result. For instance, suppose an individual asserts that Einstein had been aborted in utero, the world would never have learned about relativity, or that if Monet had been trained as a butcher rather than going to college, the impressionistic movement would have never influenced modern art. Such hypotheses are misleading lines of argument because it is often possible that some other individual would have solved the relativistic equations or introduced an impressionistic art style. The speculation might make an interesting thought-experiment, but it is simply useless when it comes to actually proving anything about the real world. A common example is the idea that one "owes" her success to another individual who taught her. For instance, "You owe me part of your increased salary. If I hadn't taught you how to recognize logical fallacies, you would be flipping hamburgers at McDonald's for minimum wages right now instead of taking in hundreds of thousands of dollars as a lawyer." Perhaps. But perhaps the audience would have learned about logical fallacies elsewhere, so the hypothetical situation described is meaningless.
Complex Question (Also called the "Loaded Question"): Phrasing a question or statement in such as way as to imply another unproven statement is true without evidence or discussion. This fallacy often overlaps with begging the question (above), since it also presupposes a definite answer to a previous, unstated question. For instance, if I were to ask you “Have you stopped taking drugs yet?” my hidden supposition is that you have been taking drugs. Such a question cannot be answered with a simple yes or no answer. It is not a simple question but consists of several questions rolled into one. In this case the unstated question is, “Have you taken drugs in the past?” followed by, “If you have taken drugs in the past, have you stopped taking them now?” In cross-examination, a lawyer might ask a flustered witness, “Where did you hide the evidence?” or "when did you stop beating your wife?" The intelligent procedure when faced with such a question is to analyze its component parts. If one answers or discusses the prior, implicit question first, the explicit question may dissolve.
Complex questions appear in written argument frequently. A student might write, “Why is private development of resources so much more efficient than any public control?” The rhetorical question leads directly into his next argument. However, an observant reader may disagree, recognizing the prior, implicit question remains unaddressed. That question is, of course, whether private development of resources really is more efficient in all cases, a point which the author is skipping entirely and merely assuming to be true without discussion.
Contradictory Premises: Establishing a premise in such a way that it contradicts another, earlier premise. For instance, "If God can do anything, he can make a stone so heavy that he can't lift it." The first premise establishes a deity that has the irresistible capacity to move other objects. The second premise establishes an immovable object impervious to any movement. If the first object capable of moving anything exists, by definition, the immovable object cannot exist, and vice-versa.
Saturday, May 23, 2009
((((((((((FIRST TEST - PL111))))))))))
IMPORTANT NOTICE
Dear critical thinkers!
The first test will be held on 5th May 2012. No make-up test allowed. If you get sick and may not sit for the test please bring AUTHORIZED documentation from OUR clinic or from the hospitals warranted by the UDSM.
Thank you!
Dear critical thinkers!
The first test will be held on 5th May 2012. No make-up test allowed. If you get sick and may not sit for the test please bring AUTHORIZED documentation from OUR clinic or from the hospitals warranted by the UDSM.
Thank you!
Friday, May 22, 2009
TEST TEST TEST
ANNOUNCEMENT OF FINAL TESTS
MONDAY TEST FOR BAMC AND BAJ STUDENTS
TUESDAY TEST FOR PR STUDENTS
Two main areas of concentration : categorical and hypothetical syllogisms :)-
-(((((((((((((((GOOD LUCK)))))))))))))))))))-
MONDAY TEST FOR BAMC AND BAJ STUDENTS
TUESDAY TEST FOR PR STUDENTS
Two main areas of concentration : categorical and hypothetical syllogisms :)-
-(((((((((((((((GOOD LUCK)))))))))))))))))))-
Wednesday, May 20, 2009
Rules for solving syllogisms
Rules for solving syllogistic arguments:
1. The term that the premises have in common is called the middle or common term and will never appear in the conclusion. The mathematical, LOGICAL nature of this reasoning should be stressed (cross out like terms).
2. In the conclusion, the subject term must come from one premise and the predicate term from the other premise. The conclusion cannot be identical to a premise.
3. The strength of a conclusion can be no greater than that of the weaker of the two premises. If one premise is universal (ALL, NO) and one is particular (SOME), the conclusion must be particular (SOME).
4. Only two affirmative premises can produce an affirmative conclusion. If one premise is negative, the conclusion will be negative. If both conclusions are negative, there will likely be NO conclusion.
1. The term that the premises have in common is called the middle or common term and will never appear in the conclusion. The mathematical, LOGICAL nature of this reasoning should be stressed (cross out like terms).
2. In the conclusion, the subject term must come from one premise and the predicate term from the other premise. The conclusion cannot be identical to a premise.
3. The strength of a conclusion can be no greater than that of the weaker of the two premises. If one premise is universal (ALL, NO) and one is particular (SOME), the conclusion must be particular (SOME).
4. Only two affirmative premises can produce an affirmative conclusion. If one premise is negative, the conclusion will be negative. If both conclusions are negative, there will likely be NO conclusion.
More on Deductive and Inductive Reasoning
Inductive reasoning goes from the specific to the general. Deductive reasoning goes from the general to the specific. Let me elaborate.
Deductive reasoning starts with a general rule, a premise, which we know to be true, or we accept it to be true for the circumstances. Then from that rule, we make a conclusion about something specific. Example:
All turtles have shells
The animal I have captured is a turtle
I conclude that the animal in my bag has a shell
A conclusion reached with deductive reasoning is logically sound, and airtight, assuming the premise is true. Deductive reasoning is fully convincing when it is based on a definition. If *by definition* a shilling is a flat disc, copper in color and has a profile of Nyerere on it, then I can be sure the shilling in my pocket has those qualities.
The obvious strength of deductive reasoning is that conclusions derived with it are fully certain. The weakness, which was illustrated in the most recent example, is that no new information is added. The fact that the shilling in my pocket is a copper disc with Nyerere on it was clear from the initial data, so the conclusion hasn't added any new information.
Inductive reasoning is making a conclusion based on a set of empirical data. If I observe that something is true many times, concluding that it will be true in all instances, is a use of inductive reasoning. Example:
All sheep that I've seen are white
All sheep must be white
This example makes inductive reasoning seem useless, but it is in fact very powerful. Most scientific discoveries are made with use of inductive reasoning. A majority of mathematical discoveries come about from conclusions made with inductive reasoning, or observation. But the key word is "discovery." With induction something can be discovered but not proven.
The general flow of events is like this: a)make observations b)form conclusions from empirical data c)prove conclusions with deductive reasoning. So if I notice that all triangles I come across have 180 degrees, through inductive reasoning I may form a hypothesis that *all* triangles have 180 degrees. But now that inductive reasoning has pointed me in the right direction, deductive reasoning allows me to prove my hypothesis as fact.
There is just too much data out there to gather, to just go around blindly using deductive reasoning. Induction allows us to mine the data, and points out significant bits of information. From there we can prove things and form hard facts.
Deductive reasoning starts with a general rule, a premise, which we know to be true, or we accept it to be true for the circumstances. Then from that rule, we make a conclusion about something specific. Example:
All turtles have shells
The animal I have captured is a turtle
I conclude that the animal in my bag has a shell
A conclusion reached with deductive reasoning is logically sound, and airtight, assuming the premise is true. Deductive reasoning is fully convincing when it is based on a definition. If *by definition* a shilling is a flat disc, copper in color and has a profile of Nyerere on it, then I can be sure the shilling in my pocket has those qualities.
The obvious strength of deductive reasoning is that conclusions derived with it are fully certain. The weakness, which was illustrated in the most recent example, is that no new information is added. The fact that the shilling in my pocket is a copper disc with Nyerere on it was clear from the initial data, so the conclusion hasn't added any new information.
Inductive reasoning is making a conclusion based on a set of empirical data. If I observe that something is true many times, concluding that it will be true in all instances, is a use of inductive reasoning. Example:
All sheep that I've seen are white
All sheep must be white
This example makes inductive reasoning seem useless, but it is in fact very powerful. Most scientific discoveries are made with use of inductive reasoning. A majority of mathematical discoveries come about from conclusions made with inductive reasoning, or observation. But the key word is "discovery." With induction something can be discovered but not proven.
The general flow of events is like this: a)make observations b)form conclusions from empirical data c)prove conclusions with deductive reasoning. So if I notice that all triangles I come across have 180 degrees, through inductive reasoning I may form a hypothesis that *all* triangles have 180 degrees. But now that inductive reasoning has pointed me in the right direction, deductive reasoning allows me to prove my hypothesis as fact.
There is just too much data out there to gather, to just go around blindly using deductive reasoning. Induction allows us to mine the data, and points out significant bits of information. From there we can prove things and form hard facts.
Friday, May 15, 2009
Complete the Syllogisms
Supply the conclusions of the following syllogisms: (just for fun) Enjoy them!
Wednesday, May 13, 2009
Categorical Syllogism
A form of deductive reasoning consisting of a major premise, a minor premise, and a conclusion; for example,
All humans are mortal, the major premise,
I am a human, the minor premise,
therefore, I am mortal, the conclusion.
Basic structure
A categorical syllogism consists of three parts: the major premise, the minor premise, and the conclusion, each part of which is a categorical proposition, and each categorical proposition containing two categorical terms.
Major premise: All humans are mortal.
Minor premise: Some animals are human.
Conclusion: Some animals are mortal.
Each of the three distinct terms represents a category, in this example, "human," "mortal," and "animal." "Mortal" is the major term; "animal," the minor term. The premises also have one term in common with each other, which is known as the middle term — in this example, "human." Here the major premise is universal and the minor particular, but this need not be so.
For example:
Major premise: All mortals die.
Minor premise: All men are mortals.
Conclusion: All men die.
The premises and conclusion of a syllogism can be any of four types, which are labelled by letters as follows. The meaning of the letters is given by the table:
By definition, S is the subject of the conclusion, P is the predicate of the conclusion, M is the middle term, the major premise links M with P and the minor premise links M with S.
However, the middle term can be either the subject or the predicate of each premise that it appears in. This gives rise to another classification of syllogisms known as the figure. Given that in each case the conclusion is S-P, the four figures are:
Putting it all together, there are 256 possible types of syllogisms (or 512 if the order of the major and minor premises is changed, although this makes no difference logically). Each premise and the conclusion can be of type A, E, I or O, and the syllogism can be any of the four figures.
A syllogism can be described briefly by giving the letters for the premises and conclusion followed by the number for t he figure. For example, the syllogisms above are AAA-1.
Of course, the vast majority of the 256 possible forms of syllogism are invalid (the conclusion does not follow logically from the premises).
The letters A, E, I, O have been used since the medieval Schools to form mnemonic names for the forms as follows: 'Barbara' stands for AAA, 'Celarent' for EAE etc.
A sample syllogism of each type follows.
A form of deductive reasoning consisting of a major premise, a minor premise, and a conclusion; for example,
All humans are mortal, the major premise,
I am a human, the minor premise,
therefore, I am mortal, the conclusion.
Basic structure
A categorical syllogism consists of three parts: the major premise, the minor premise, and the conclusion, each part of which is a categorical proposition, and each categorical proposition containing two categorical terms.
Major premise: All humans are mortal.
Minor premise: Some animals are human.
Conclusion: Some animals are mortal.
Each of the three distinct terms represents a category, in this example, "human," "mortal," and "animal." "Mortal" is the major term; "animal," the minor term. The premises also have one term in common with each other, which is known as the middle term — in this example, "human." Here the major premise is universal and the minor particular, but this need not be so.
For example:
Major premise: All mortals die.
Minor premise: All men are mortals.
Conclusion: All men die.
The premises and conclusion of a syllogism can be any of four types, which are labelled by letters as follows. The meaning of the letters is given by the table:
By definition, S is the subject of the conclusion, P is the predicate of the conclusion, M is the middle term, the major premise links M with P and the minor premise links M with S.
However, the middle term can be either the subject or the predicate of each premise that it appears in. This gives rise to another classification of syllogisms known as the figure. Given that in each case the conclusion is S-P, the four figures are:
Putting it all together, there are 256 possible types of syllogisms (or 512 if the order of the major and minor premises is changed, although this makes no difference logically). Each premise and the conclusion can be of type A, E, I or O, and the syllogism can be any of the four figures.
A syllogism can be described briefly by giving the letters for the premises and conclusion followed by the number for t he figure. For example, the syllogisms above are AAA-1.
Of course, the vast majority of the 256 possible forms of syllogism are invalid (the conclusion does not follow logically from the premises).
The letters A, E, I, O have been used since the medieval Schools to form mnemonic names for the forms as follows: 'Barbara' stands for AAA, 'Celarent' for EAE etc.
A sample syllogism of each type follows.
Monday, May 11, 2009
Deduction & Induction
Deductive and Inductive Thinking
________________________________________
In logic, we often refer to the two broad methods of reasoning as the deductive and inductive approaches.
Deductive reasoning works from the more general to the more specific. Sometimes this is informally called a "top-down" approach.
We might begin with thinking up a theory about our topic of interest. We then narrow that down into more specific hypotheses that we can test. We narrow down even further when we collect observations to address the hypotheses. This ultimately leads us to be able to test the hypotheses with specific data - a confirmation (or not) of our original theories.
Inductive reasoning works the other way, moving from specific observations to broader generalizations and theories. Informally, we sometimes call this a "bottom up" approach (please note that it's "bottom up" and not "bottoms up" which is the kind of thing the bartender says to customers when he's trying to close for the night!).
In inductive reasoning, we begin with specific observations and measures, begin to detect patterns and regularities, formulate some tentative hypotheses that we can explore, and finally end up developing some general conclusions or theories.
These two methods of reasoning have a very different "feel" to them when you're conducting research.
Inductive reasoning, by its very nature, is more open-ended and exploratory, especially at the beginning.
Deductive reasoning is more narrow in nature and is concerned with testing or confirming hypotheses. Even though a particular study may look like it's purely deductive (e.g., an experiment designed to test the hypothesized effects of some treatment on some outcome), most social research involves both inductive and deductive reasoning processes at some time in the project.
Deductive and Inductive Thinking
________________________________________
In logic, we often refer to the two broad methods of reasoning as the deductive and inductive approaches.
Deductive reasoning works from the more general to the more specific. Sometimes this is informally called a "top-down" approach.
We might begin with thinking up a theory about our topic of interest. We then narrow that down into more specific hypotheses that we can test. We narrow down even further when we collect observations to address the hypotheses. This ultimately leads us to be able to test the hypotheses with specific data - a confirmation (or not) of our original theories.
Inductive reasoning works the other way, moving from specific observations to broader generalizations and theories. Informally, we sometimes call this a "bottom up" approach (please note that it's "bottom up" and not "bottoms up" which is the kind of thing the bartender says to customers when he's trying to close for the night!).
In inductive reasoning, we begin with specific observations and measures, begin to detect patterns and regularities, formulate some tentative hypotheses that we can explore, and finally end up developing some general conclusions or theories.
These two methods of reasoning have a very different "feel" to them when you're conducting research.
Inductive reasoning, by its very nature, is more open-ended and exploratory, especially at the beginning.
Deductive reasoning is more narrow in nature and is concerned with testing or confirming hypotheses. Even though a particular study may look like it's purely deductive (e.g., an experiment designed to test the hypothesized effects of some treatment on some outcome), most social research involves both inductive and deductive reasoning processes at some time in the project.
Tuesday, May 5, 2009
Categorical Syllogisms
Standard Form Categorical Syllogisms
In order to understand standard form categorical syllogisms it will be helpful to define several words and phrases:
•Syllogism – a deductive argument in which the conclusion is drawn from two premises.
•Categorical syllogism – a deductive argument consisting of three categorical
propositions with exactly three shared terms, two terms per proposition.
•Standard form categorical syllogism – a categorical syllogism consisting of
standard form categorical propositions arranged in a specific order, with the major
premise stated first, then the minor premise, and then the conclusion.
•Major term – the term occurring in the predicate of the conclusion in a standard
form categorical syllogism.
•Minor term – the term occurring in the subject of the conclusion in a standard
form categorical syllogism.
•Middle term – the term occurring in both the major and minor premises of a
standard form categorical syllogism, but not in the conclusion.
•Major premise – the premise of a categorical syllogism that contains an instance
of the major term.
•Minor term – the premise of a categorical syllogism that contains an instance of
the minor term.
Note: the major and minor premises are not determined by their placement in a
categorical syllogism, but by terms that are contained within them.
Both premises of a syllogism contain the middle term, but only the major premise and the conclusion contain the major term, and only the minor premise and the conclusion contain the minor term.
In the following argument the minor premise is stated first, then the major premise, and then the conclusion:
All disciples are Saints.
Some disciples are preachers.
Therefore some saints are preachers.
The major term in this argument is “preachers,” because it is the term in the predicate of the conclusion.
The minor term is “saint,” because it is the term in the subject of the conclusion. The first premise contains the minor term, so it is the minor premise. The second premise contains the major term, so it is the major premise.
This is a valid categorical syllogism, but it is not a standard form syllogism, because the premises are not stated in the standard order with the major premise being stated first. It should be noted that “standard form” is simply a matter of convention or definition.
There is nothing that makes a standard form syllogism “better” than a non-standard form syllogism, and in fact arguments that are not in standard form are sometimes seen to be more persuasive, because they can be written or spoken in a more natural format.
Consider the standard form syllogism below,
Some disciples are preachers.
All disciples are Saints.
Therefore some saints are preachers.
With this more natural statement of the same argument:
It must be true that some saints are preachers, since all disciples are saints, and
some disciples are preachers.
Even in this form the argument is a bit stilted, since it still conforms to the rigors of standard form categorical propositions, but most would prefer the latter to the former in everyday language.
However, it is easier to work with standard form categorical syllogisms, so for this
purpose it is to be preferred over the less rigorous arguments.
Mood and Figure
All standard form categorical syllogisms can be described in terms of their mood and
figure. The mood of a syllogism is represented by the three letters that represent the type of each proposition in the syllogism. So a standard form syllogism with three universal affirmative propositions has a mood of AAA. However, the mood of a syllogism does not fully characterize its form. For example consider these two arguments each of which has a mood of AAA.
Major premise: All men are mortal.
Minor premise: All preachers are men.
Conclusion: All preachers are mortal.
Major premise: All Christians are men.
Minor premise: All preachers are men.
Conclusion: All preachers are Christians.
Both of these arguments have a mood of AAA, but they differ in how the middle term is
placed. The first argument places the middle term in the subject of the major premise, and the predicate of the minor premise, but the second argument places the middle term in the predicate of both major and minor premises. So, although both have the same mood, they differ in form.
Next time we will see the 4 Figures and how they work! keeping checking!
Sunday, April 26, 2009
Anatomy of Arguments
THE ANATOMY OF AN ARGUMENT
Neither a closed mind nor an empty one is likely to produce much that would
qualify as effective reasoning.
—Nickerson (1986, p. 1)
The technical meaning of the word argument is different from its everyday meaning. When we use the word argument in everyday language, it means a dispute or a quarrel. We say two people "are having an argument" when they disagree about something in a heated or emotional way.
More technically, an argument consists of one or more statements that are used to provide support for a conclusion. The statements that provide the support for a conclusion are called the reasons or premises of the argument.
The reasons or premises are presented in order to persuade the reader or listener that the conclusion is true or probably true. Let's consider an example.
Suppose that I want to convince you to stay in college until graduation. Here are some reasons (premises) that I could give. You can think of this as an addition problem with each premise summing to the conclusion.
Premise #1: College graduates earn more money than college dropouts or people who
have never attended college.
+ Premise #2: College graduates report that they are more satisfied with their lives than people who have not graduated from college.
+ Premise #3: College graduates are healthier and live longer than people who have not graduated from college.
+ Premise #4: College graduates have jobs that are more interesting and more
responsible than people who have not graduated from college.
Conclusion: You should graduate from college.
Arguments are sometimes called "the giving of reasons." Harmon (1986) calls this process "a change in view" because the objective is to change an "old view" or belief
into a "new view" or belief with reasoning. Old View Reasoning New View or Belief or Belief
Every argument will have one or more premises (or reasons) and one or more conclusions. Usually, there will be several premises for one conclusion, but other combinations (one premise for several conclusions and several premises for several conclusions) are possible. If you cannot identify at least one premise and at least one conclusion, then it is not an argument.
Of course, in everyday, natural language arguments, the premises and conclusions are not labeled. They are usually embedded in extended prose. The extended prose could be a paragraph, a section or chapter of a book, or even an entire book or semester-long class.
Here are some examples of prose that are not arguments:
I like my critical thinking course better than my chemistry course. (No reasons
are given for this preference.)
We drove up to the mountains, went skiing, then drove home. (This is just a descriptive list of activities linked together. There are no reasons or conclusions.)
Buy your burgers at Burgerland. (No reasons given, but see the section below
because reasons are often inferred from context in statements like this one.)
We saw the Martians land. (This is a simple description.)
Never trust anyone under 30. (This is an opinion without reasons.)
Is dinner ready? (simple question.)
It may seem that it should be fairly simple to determine whether a statement or set of statements contain an argument, but in everyday language most arguments are incomplete.
Sometimes the premises aren't stated, but are inferred, and other times the conclusion is unstated. Sometimes arguments are deliberately disguised so that it may appear that the speakers are not supporting some conclusion, when they really are. Consider the popular automobile advertisement that goes something like this:
More people have bought LaBaroness automobiles than any other American car.
At first glance, this seems like a straightforward declarative sentence with no
reasons and no conclusion.
But, the advertisers expect consumers to convert this sentence into an argument. When you hear this sentence, you presumably start generating your own reasons for the popularity of LaBaroness. If more people are buying it, it must be best and shouldn't you also buy the best? This is an example in which the listener supplies both the reasons and the conclusion.
Statements very similar to this one can be found in advertisements for a diverse assortment of products including beer, beauty supplies, fitness clubs, and airlines.
If an advertiser wants to be sure that you supply the missing reasons and conclusion, the advertisement could be altered slightly so that it now reads:
More people have bought LaBaroness automobiles than any other American car. There
must be some very good reasons.
Notice that a second sentence was added, but no reasons were given. It is expected that the second sentence will cue listeners (or readers) to start supplying their own reasons.
Premises
The premises are the reasons that support a conclusion. They are the "why" part of an argument.
In everyday language, they can appear anywhere among a set of statements. Sometimes, the conclusion will be stated first followed by its premises. (Here is what I believe and the reasons for this belief are . . ..)
Other times the conclusion may be presented last or embedded in the middle of a paragraph or other text with premises both before and after it. Premises are not always easy to recognize. There are certain key words, called premise indicators or premise markers, that often signal that what comes after them is a premise. Although premise indicators aren't always followed by a premise, they often are, and for this reason, it is a good idea to check for these key words when identifying premises. These terms often indicate that what follows is a reason.
Premise Indicators
because
for
since (when it means because and not the passage of time)
if
given that (or being that)
as shown by
as indicated by
the reasons are
it may be inferred (or deduced) from
the evidence consists of
in the first place (suggests that a list of premises will follow)
secondly
seeing that
assuming that
it follows from
whereas
Here are some simple examples of the use of premise indicators.
You should graduate from college because you will earn more money with a
college degree.
The need for the United States to send troops to Central America is indicated
by the buildup of armed rebels in countries neighboring those with civil wars.
Seeing that the current policy of supplying organ transplants is benefiting the
rich, a new program is needed.
Premises can be "matters of fact" or "matters of opinion" or both. Consider, for
example, the following sentences:
All teenagers should be taught safe sex practices because of the risk of AIDS
and other sexually transmitted diseases. (The reason is a matter of fact.)
All teenagers should be taught how to knit because this will provide them with
an enjoyable hobby. (The reason is a matter of opinion.)
Conclusions
The conclusion is the purpose or the "what" of the argument. It is the belief or point of view that is supported or defended with the premises. Both the premises and the conclusion are important, and both are essential components of any argument.
It is usually easier to identify the conclusion of an argument than the other components.
For this reason, it is a good idea to start with the conclusion when you are analyzing arguments. There are conclusion indicators or conclusion markers that indicate that what follows is probably a conclusion. As with premise indicators, they do not guarantee that a conclusion follows them.
Conclusion Indicators
therefore
hence
so
thus
consequently
then
shows that (we can see that)
accordingly
it follows that
we may infer (conclude) (deduce) that
in summary
as a result
for all these reasons
it is clear that
Some simple examples of the use of conclusion indicators are:
Based on all of the reasons just stated, we can conclude that the flow of illegal drugs must be stopped.
In summary, postal rates must be increased because we can no longer afford to run the postal system with a deficit.
We have had very little rain this season. Consequently, water will have to be rationed.
Neither a closed mind nor an empty one is likely to produce much that would
qualify as effective reasoning.
—Nickerson (1986, p. 1)
The technical meaning of the word argument is different from its everyday meaning. When we use the word argument in everyday language, it means a dispute or a quarrel. We say two people "are having an argument" when they disagree about something in a heated or emotional way.
More technically, an argument consists of one or more statements that are used to provide support for a conclusion. The statements that provide the support for a conclusion are called the reasons or premises of the argument.
The reasons or premises are presented in order to persuade the reader or listener that the conclusion is true or probably true. Let's consider an example.
Suppose that I want to convince you to stay in college until graduation. Here are some reasons (premises) that I could give. You can think of this as an addition problem with each premise summing to the conclusion.
Premise #1: College graduates earn more money than college dropouts or people who
have never attended college.
+ Premise #2: College graduates report that they are more satisfied with their lives than people who have not graduated from college.
+ Premise #3: College graduates are healthier and live longer than people who have not graduated from college.
+ Premise #4: College graduates have jobs that are more interesting and more
responsible than people who have not graduated from college.
Conclusion: You should graduate from college.
Arguments are sometimes called "the giving of reasons." Harmon (1986) calls this process "a change in view" because the objective is to change an "old view" or belief
into a "new view" or belief with reasoning. Old View Reasoning New View or Belief or Belief
Every argument will have one or more premises (or reasons) and one or more conclusions. Usually, there will be several premises for one conclusion, but other combinations (one premise for several conclusions and several premises for several conclusions) are possible. If you cannot identify at least one premise and at least one conclusion, then it is not an argument.
Of course, in everyday, natural language arguments, the premises and conclusions are not labeled. They are usually embedded in extended prose. The extended prose could be a paragraph, a section or chapter of a book, or even an entire book or semester-long class.
Here are some examples of prose that are not arguments:
I like my critical thinking course better than my chemistry course. (No reasons
are given for this preference.)
We drove up to the mountains, went skiing, then drove home. (This is just a descriptive list of activities linked together. There are no reasons or conclusions.)
Buy your burgers at Burgerland. (No reasons given, but see the section below
because reasons are often inferred from context in statements like this one.)
We saw the Martians land. (This is a simple description.)
Never trust anyone under 30. (This is an opinion without reasons.)
Is dinner ready? (simple question.)
It may seem that it should be fairly simple to determine whether a statement or set of statements contain an argument, but in everyday language most arguments are incomplete.
Sometimes the premises aren't stated, but are inferred, and other times the conclusion is unstated. Sometimes arguments are deliberately disguised so that it may appear that the speakers are not supporting some conclusion, when they really are. Consider the popular automobile advertisement that goes something like this:
More people have bought LaBaroness automobiles than any other American car.
At first glance, this seems like a straightforward declarative sentence with no
reasons and no conclusion.
But, the advertisers expect consumers to convert this sentence into an argument. When you hear this sentence, you presumably start generating your own reasons for the popularity of LaBaroness. If more people are buying it, it must be best and shouldn't you also buy the best? This is an example in which the listener supplies both the reasons and the conclusion.
Statements very similar to this one can be found in advertisements for a diverse assortment of products including beer, beauty supplies, fitness clubs, and airlines.
If an advertiser wants to be sure that you supply the missing reasons and conclusion, the advertisement could be altered slightly so that it now reads:
More people have bought LaBaroness automobiles than any other American car. There
must be some very good reasons.
Notice that a second sentence was added, but no reasons were given. It is expected that the second sentence will cue listeners (or readers) to start supplying their own reasons.
Premises
The premises are the reasons that support a conclusion. They are the "why" part of an argument.
In everyday language, they can appear anywhere among a set of statements. Sometimes, the conclusion will be stated first followed by its premises. (Here is what I believe and the reasons for this belief are . . ..)
Other times the conclusion may be presented last or embedded in the middle of a paragraph or other text with premises both before and after it. Premises are not always easy to recognize. There are certain key words, called premise indicators or premise markers, that often signal that what comes after them is a premise. Although premise indicators aren't always followed by a premise, they often are, and for this reason, it is a good idea to check for these key words when identifying premises. These terms often indicate that what follows is a reason.
Premise Indicators
because
for
since (when it means because and not the passage of time)
if
given that (or being that)
as shown by
as indicated by
the reasons are
it may be inferred (or deduced) from
the evidence consists of
in the first place (suggests that a list of premises will follow)
secondly
seeing that
assuming that
it follows from
whereas
Here are some simple examples of the use of premise indicators.
You should graduate from college because you will earn more money with a
college degree.
The need for the United States to send troops to Central America is indicated
by the buildup of armed rebels in countries neighboring those with civil wars.
Seeing that the current policy of supplying organ transplants is benefiting the
rich, a new program is needed.
Premises can be "matters of fact" or "matters of opinion" or both. Consider, for
example, the following sentences:
All teenagers should be taught safe sex practices because of the risk of AIDS
and other sexually transmitted diseases. (The reason is a matter of fact.)
All teenagers should be taught how to knit because this will provide them with
an enjoyable hobby. (The reason is a matter of opinion.)
Conclusions
The conclusion is the purpose or the "what" of the argument. It is the belief or point of view that is supported or defended with the premises. Both the premises and the conclusion are important, and both are essential components of any argument.
It is usually easier to identify the conclusion of an argument than the other components.
For this reason, it is a good idea to start with the conclusion when you are analyzing arguments. There are conclusion indicators or conclusion markers that indicate that what follows is probably a conclusion. As with premise indicators, they do not guarantee that a conclusion follows them.
Conclusion Indicators
therefore
hence
so
thus
consequently
then
shows that (we can see that)
accordingly
it follows that
we may infer (conclude) (deduce) that
in summary
as a result
for all these reasons
it is clear that
Some simple examples of the use of conclusion indicators are:
Based on all of the reasons just stated, we can conclude that the flow of illegal drugs must be stopped.
In summary, postal rates must be increased because we can no longer afford to run the postal system with a deficit.
We have had very little rain this season. Consequently, water will have to be rationed.
Thursday, April 16, 2009
Language, Concepts, and Classification
Language, Concepts, and Classification
Language is our basic tool of thought and speech. A word is the linguistic vehicle we use to express a concept.
Concepts are ideas that represent classes of things we have grouped together. Concepts function as mental file folders.
The things that are put in a mental file folder are called the referents of the concept.
Classification consists of organizing a set of things into groups by using concepts.
Example:
The word "dog" refers to the concept DOG, whereas all the individual dogs in the world are referents of the concept DOG. All the referents of the concept DOG can be placed in one group and distinguished from the referents of other concepts, such as CAT, that are placed in other groups.
Genus and Species
Some concepts are broader than other concepts. ANIMAL is broader than DOG because there are other kinds of animals besides dogs.
If all the referents of one concept are included in another, but one concept refers to more things than the other, then the broader concept is called the genus, and the narrower one is called the species.
If a species is a file folder, a genus is a file drawer containing many folders.
Example:
ANIMAL is the genus, and all the different kinds of animals, such as DOG and CAT, are species of this genus. This is so because all the referents of the concept DOG are included in the concept ANIMAL, but the concept ANIMAL refers to more things than dogs.
Abstract and Concrete
The referents of our concepts are concrete; each is a single, individual object.
A concept is abstract because it:
1. refers to a group of objects, not just to a single thing;
2. groups together things that differ from one another. Things are grouped together, not because they are identical, but because they are similar in some respect.
Lassie (as the name of a specific dog) refers to a concrete object, whereas the concept DOG is abstract because it refers to a group of objects that are similar in certain respects.
Example:
Lassie (as the name of a specific dog) refers to a concrete object, while the concept DOG is abstract because it refers to a group of objects that are similar in certain respects.
Order of Increasing Abstractness
Abstractness is a comparative property.
Any concept is abstract to some degree. However, a species is less abstract than the genus to which it belongs.
The genus is a larger and broader group; it has more referents than the species does.
The distinction between abstract and concrete allows us to classify not only things, but also concepts, because some concepts are more abstract than others.
Example:
The concept LOVE is more abstract than its species, such as ROMANTIC LOVE, but less abstract than its genus, EMOTION.
Since EMOTION is more abstract than specific emotions, such as LOVE and HATE, it allows us to classify the different species of emotions under the genus EMOTION.
Monday, April 13, 2009
Online Dictionaries
Monday, April 6, 2009
Explanations and Description
Let us examine each of these.
But before we go to argument structure lets look at two things which you ought to differentiate from argument, they are explanation and description.
An explanation is not an argument. Whereas an argument is a series of statements designed to support or establish the truth of an idea, an explanation is a series of statements designed to shed light on some event that is already accepted as a matter of fact.
Technically, an explanation is composed of two parts: the explanandum and the explanans.
The explanandum is the event or phenomenon or thing which is supposed to be explained.
The explanans is the series of statements which is supposed to do the actual explaining.
Here is an example:
1. Smoke appears because of fire: a combination of flammable material, oxygen, and sufficient heat.
The phrase “smoke appears” is the explanandum and the phrase “fire: a combination of flammable material, oxygen, and sufficient heat” is the explanans.
In fact, this explanans itself consists of an entire explanation — “fire” plus the reason why fires happen.
Although people gain much information from their impressions, most matters of fact depend upon reasoning about causes and effects, even though people do not directly experience causal relations. What, then, are causal relations?
According to Hume they have three components: contiguity of time and place (bars and alcohol), temporal priority of the cause (boys and girls - binge), and constant conjunction (condoms - sex).
In order for x to be the cause of y, x and y must exist adjacent to each other in space and time, x must precede y, and x and y must invariably exist together.
Description:
In a description tells us about what a person, place, or thing, or an event was/is like.
Helper Words:
Properties Measurement Analogy Location
size length is like in
colour width resembles above
shape mass/weight below
purpose speed beside
near
north/east/south/west
DESCRIPTIVE WORDS
SOUND
ringing cheeping gasping smashing piercing peeping
whooping tinkling raucous chattering crooning bellowing
sobbing bumping snarling growling pitch crying
thumping burping croaking clattering yapping keening
splashing yelping rustling volume squealing howling
barking sniveling moaning pealing tone rattling
grunting clanging coughing quacking whining gagging
fizzing wheezing honking hissing bawling trumpeting
swishing sneezing rumbling bubbling ripping cooing
chirping shouting shuffling tearing popping roaring
thunderous scratching snorting crashing crunching cackling
tolling clucking silent tapping soothing crowing
tranquil melodious cacophonous singing quiet tune
loud tinkling noisy rhythmic mumbling twittering
din beat blaring cawing racket chattering
murmuring whistling clapping booming whispering mewing
snapping snoring yelling mooing crackling sighing
TOUCH AND TEXTURE
pressed damp fluted tickling sculptured dry
knobbed raw corrugated downy chapped scratchy
dirty grimy sopping itching abrasive dusty
scaled rasping prickly clammy pulpy kiss
scarred glossy wet pocked tweedy matte
moist woolly hard foamy dank patina
gripped burning hairy soft cottony scorching
furry bumpy rocking cushioned fluffy searing
fuzzy boiling sheer sheen scalding stinging
sandy warm shiny polished hot engraved
gritty inlaid soapy bubbly grooved cool
glassy ivory biting sharp rutted piercing
silky numbing velvety smooth freezing steely
keen icy corduroy grainy cold metallic
fine waxy coarse greasy curdled slimy
splintered lacy tangled spiky slippery creamy
matted slick shaggy bushy fiery stubbly
COLOR AND VISUAL QUALITIES
red saffron bright dark scarlet gold
dull light carnelian silver rose chocolate
crimson chrome lilac sienna salmon lime
copper vermilion yellow bronze avocado coral
primrose pale purple lemon canary violet
pink cerise mauve ruddy mahogany topaz
blue amber ebony flushed maroon amethyst
crystalline cyan navy wine white poppy
cobalt burgundy olive fuchsia turquoise claret
drab chartreuse orchid brilliant clear black
obsidian transparent khaki opaque translucent lavender
glassy jet gay rust carmine sapphire
dun cordovan indigo milky tan grizzly
ocher flesh buff brindle umber peach
mustard ultramarine snowy chestnut green smoky
sepia mint brass walnut pearl aqua
ruby emerald twinkling bistre sooty shimmering
jade plum charcoal maize lake iridescent
garnet slate spruce puce magenta sable
pearly aquamarine ivory henna citrine onyx
azure cream orange
SMELL
perfumed lilac earthy stinking fetid loamy
lemon scent odor fragrance sweaty sharp
rose lime rotten biting pungent musty
plastic acrid flowery fishy mildewed spicy
acid moldy doggy nauseating redolent skunky
dirty sweet tart minty moist putrid
sour fresh musty spoiled
PATTERN AND SHAPE
round parallel narrow reticulated crested wide
flat spherical globe rounded shallow drooping
erect dappled rolling orb hemisphere ball
shapely checkered adjacent curved pied concentric
triangle sharp short depressed swollen long
concave pyramid cone convex streamlined sunken
square diagonal contoured protruding banded terrain
horizontal rectangle cube vertical aquiline veined
cylinder depth disc palmate box width
plate pinnate spiked thread height arc
elliptical length worm-like crowned cupped serpentine
girth crescent pentagon breadth sinuous baggy
tight winding spotted oval hexagon octagon
tetrahedral solid lanky corkscrew helix curly
frail polyhedron trapezoid thin fat crystalline
fanned oval pointed plump ovate ellipsoidal
Let us examine each of these.
But before we go to argument structure lets look at two things which you ought to differentiate from argument, they are explanation and description.
An explanation is not an argument. Whereas an argument is a series of statements designed to support or establish the truth of an idea, an explanation is a series of statements designed to shed light on some event that is already accepted as a matter of fact.
Technically, an explanation is composed of two parts: the explanandum and the explanans.
The explanandum is the event or phenomenon or thing which is supposed to be explained.
The explanans is the series of statements which is supposed to do the actual explaining.
Here is an example:
1. Smoke appears because of fire: a combination of flammable material, oxygen, and sufficient heat.
The phrase “smoke appears” is the explanandum and the phrase “fire: a combination of flammable material, oxygen, and sufficient heat” is the explanans.
In fact, this explanans itself consists of an entire explanation — “fire” plus the reason why fires happen.
Although people gain much information from their impressions, most matters of fact depend upon reasoning about causes and effects, even though people do not directly experience causal relations. What, then, are causal relations?
According to Hume they have three components: contiguity of time and place (bars and alcohol), temporal priority of the cause (boys and girls - binge), and constant conjunction (condoms - sex).
In order for x to be the cause of y, x and y must exist adjacent to each other in space and time, x must precede y, and x and y must invariably exist together.
Description:
In a description tells us about what a person, place, or thing, or an event was/is like.
Helper Words:
Properties Measurement Analogy Location
size length is like in
colour width resembles above
shape mass/weight below
purpose speed beside
near
north/east/south/west
DESCRIPTIVE WORDS
SOUND
ringing cheeping gasping smashing piercing peeping
whooping tinkling raucous chattering crooning bellowing
sobbing bumping snarling growling pitch crying
thumping burping croaking clattering yapping keening
splashing yelping rustling volume squealing howling
barking sniveling moaning pealing tone rattling
grunting clanging coughing quacking whining gagging
fizzing wheezing honking hissing bawling trumpeting
swishing sneezing rumbling bubbling ripping cooing
chirping shouting shuffling tearing popping roaring
thunderous scratching snorting crashing crunching cackling
tolling clucking silent tapping soothing crowing
tranquil melodious cacophonous singing quiet tune
loud tinkling noisy rhythmic mumbling twittering
din beat blaring cawing racket chattering
murmuring whistling clapping booming whispering mewing
snapping snoring yelling mooing crackling sighing
TOUCH AND TEXTURE
pressed damp fluted tickling sculptured dry
knobbed raw corrugated downy chapped scratchy
dirty grimy sopping itching abrasive dusty
scaled rasping prickly clammy pulpy kiss
scarred glossy wet pocked tweedy matte
moist woolly hard foamy dank patina
gripped burning hairy soft cottony scorching
furry bumpy rocking cushioned fluffy searing
fuzzy boiling sheer sheen scalding stinging
sandy warm shiny polished hot engraved
gritty inlaid soapy bubbly grooved cool
glassy ivory biting sharp rutted piercing
silky numbing velvety smooth freezing steely
keen icy corduroy grainy cold metallic
fine waxy coarse greasy curdled slimy
splintered lacy tangled spiky slippery creamy
matted slick shaggy bushy fiery stubbly
COLOR AND VISUAL QUALITIES
red saffron bright dark scarlet gold
dull light carnelian silver rose chocolate
crimson chrome lilac sienna salmon lime
copper vermilion yellow bronze avocado coral
primrose pale purple lemon canary violet
pink cerise mauve ruddy mahogany topaz
blue amber ebony flushed maroon amethyst
crystalline cyan navy wine white poppy
cobalt burgundy olive fuchsia turquoise claret
drab chartreuse orchid brilliant clear black
obsidian transparent khaki opaque translucent lavender
glassy jet gay rust carmine sapphire
dun cordovan indigo milky tan grizzly
ocher flesh buff brindle umber peach
mustard ultramarine snowy chestnut green smoky
sepia mint brass walnut pearl aqua
ruby emerald twinkling bistre sooty shimmering
jade plum charcoal maize lake iridescent
garnet slate spruce puce magenta sable
pearly aquamarine ivory henna citrine onyx
azure cream orange
SMELL
perfumed lilac earthy stinking fetid loamy
lemon scent odor fragrance sweaty sharp
rose lime rotten biting pungent musty
plastic acrid flowery fishy mildewed spicy
acid moldy doggy nauseating redolent skunky
dirty sweet tart minty moist putrid
sour fresh musty spoiled
PATTERN AND SHAPE
round parallel narrow reticulated crested wide
flat spherical globe rounded shallow drooping
erect dappled rolling orb hemisphere ball
shapely checkered adjacent curved pied concentric
triangle sharp short depressed swollen long
concave pyramid cone convex streamlined sunken
square diagonal contoured protruding banded terrain
horizontal rectangle cube vertical aquiline veined
cylinder depth disc palmate box width
plate pinnate spiked thread height arc
elliptical length worm-like crowned cupped serpentine
girth crescent pentagon breadth sinuous baggy
tight winding spotted oval hexagon octagon
tetrahedral solid lanky corkscrew helix curly
frail polyhedron trapezoid thin fat crystalline
fanned oval pointed plump ovate ellipsoidal
The Stupid Test! Here Is A Fun And Real Challenge!
OK. Pay close attention. Here is a very simple little test comprised of four easy question to determine the level of your intellect. See if you have what it takes to be considered smart:
Your replies must be spontaneous and immediate, with no deliberating or wasting of time and PLEASE no cheating!
On your mark, get set, GO!
1: You are competing in a race and overtake the runner in second place.
In which position are you now?
2: If you overtake the last runner, what position are you now in?
This is my favorite!
3: Take 1000. Add 40. Add another 1000.
Add 30. 1000 again. Plus 20.
Plus 1000. And plus 10.
What is the total?
I know you will get this one!
4: Marie's father has five daughters:
1. Chacha
2. Cheche
3. Chichi
4. Chocho
5. ?
Now challenge your friends!
Your replies must be spontaneous and immediate, with no deliberating or wasting of time and PLEASE no cheating!
On your mark, get set, GO!
1: You are competing in a race and overtake the runner in second place.
In which position are you now?
2: If you overtake the last runner, what position are you now in?
This is my favorite!
3: Take 1000. Add 40. Add another 1000.
Add 30. 1000 again. Plus 20.
Plus 1000. And plus 10.
What is the total?
I know you will get this one!
4: Marie's father has five daughters:
1. Chacha
2. Cheche
3. Chichi
4. Chocho
5. ?
Now challenge your friends!
Wednesday, April 1, 2009
Rules for Definitions
Logicians have identified six rules for constructing a type of definition that is suitable for general purposes.
A definition should:
1. Include a genus and a differentia.
2. Be neither too broad or too narrow.
3. State the essential attributes of the concept's referents.
4. Avoid circularity.
5. Avoid negative terms.
6. Avoid vague, obscure, and metaphorical language.
Let us examine each of these in turn.
A Genus and a Differentia
A definition should include a genus and a differentia.
Example:
Humans are rational animals.
The term "animal" names the wider class to which humans belong; it classifies us as a species of the genus ANIMAL.
The term "rational" specifies an attribute that distinguishes us from other species of the same genus. This part of the definition is called the differentia--it differentiates humans from other animals.
Neither Too Broad or Too Narrow
The point of a definition is to identify the referents of a concept. A definition that does not pick out the right referents- -one that includes too much or too little--is not doing its job.
A definition is too broad if it includes things that are not referents of the concept.
Example:
Humans are two-legged animals.
This definition is too broad because the defining phrase "two-legged animal" includes birds as well as humans.
A definition is too narrow if it fails to include things that are referents of the concept.
Example:
Humans are religious animals
This definition is too narrow because, no matter how widespread religious belief may be, some people are atheists.
Essential Attributes
The term "essential" means fundamental: An essential attribute causes or explains the existence of other attributes.
Example:
The heart is an organ that goes "lub-dub, lub-dub".
The "lub-dub" sound is a superficial trait; it is merely a by-product of the heart's essential function, which is to circulate the blood.
Avoid Circularity
A circular definition tells us how a concept relates to itself, but not how it relates to other concepts or to reality. Such a definition doesn't go anywhere; it just moves in a circle.
Example:
Suppose we define "ownership" as the legal relation between people and the things they own. Because this definition uses the word "own," it defines the concept OWNERSHIP in terms of itself.
Avoid Negative Terms
A definition should not use negative terms unnecessarily.
Negative definitions should be avoided because knowing what a thing is not doesn't tell us much about what it is.
Example:
At the turn of the century, the automobile was described as a "horseless carriage." The differentia "horseless" tells us about one source of power that automobiles do not use. However, there are many sources of power automobiles do not use; what we want to know is the source they do use.
Some concepts, however, are inherently negative, and thus require negative terms in their definitions.
Example:
A "bachelor" is a man who is not married.
This has to be defined negatively, since it is an inherently negative concept.
Avoid Vagueness
This is the clarity rule. The purpose of a definition is to clarify our understanding of a concept. At the very least, therefore, the language we use in a definition should not be less clear than the concept being defined.
A vague definition is unclear because it does not give any precise criterion for membership in the concept. A definition shouldn't have borders that are even fuzzier than those of the concept being defined.
Example:
Suppose we define "maturity" as the stage of psychological development in which a person becomes well-adjusted.
Who belongs in the class of well-adjusted people and who doesn't is unclear; the class has fuzzy boundaries that are even fuzzier than those of the concept being defined.
A Definition Should Avoid Obscurity
An obscure definition is unclear because it uses abstract or technical language that is more difficult to understand than the concept itself.
Example:
Suppose we define "death" as the cessation of one's participation in finitude.
The problem here may not necessarily be one of vagueness. Within a specialized context, this definition might have a perfectly clear and definite meaning. The problem is that if technical definitions are used outside of these specialized contexts they are not clear to the layperson.
A Definition Should Avoid Metaphorical Language
A metaphorical definition is unclear because it doesn't convey the literal meaning of the concept, but only an analogy that we have to interpret.
Example:
Suppose we consider the definition: "Life is a cabaret."
Like any good metaphor, this one uses a simple image to convey a complex thought that would take many paragraphs to explain in literal terms. Metaphorical definitions leave too many questions unanswered, which is why we need literal definitions.
A definition should:
1. Include a genus and a differentia.
2. Be neither too broad or too narrow.
3. State the essential attributes of the concept's referents.
4. Avoid circularity.
5. Avoid negative terms.
6. Avoid vague, obscure, and metaphorical language.
Let us examine each of these in turn.
A Genus and a Differentia
A definition should include a genus and a differentia.
Example:
Humans are rational animals.
The term "animal" names the wider class to which humans belong; it classifies us as a species of the genus ANIMAL.
The term "rational" specifies an attribute that distinguishes us from other species of the same genus. This part of the definition is called the differentia--it differentiates humans from other animals.
Neither Too Broad or Too Narrow
The point of a definition is to identify the referents of a concept. A definition that does not pick out the right referents- -one that includes too much or too little--is not doing its job.
A definition is too broad if it includes things that are not referents of the concept.
Example:
Humans are two-legged animals.
This definition is too broad because the defining phrase "two-legged animal" includes birds as well as humans.
A definition is too narrow if it fails to include things that are referents of the concept.
Example:
Humans are religious animals
This definition is too narrow because, no matter how widespread religious belief may be, some people are atheists.
Essential Attributes
The term "essential" means fundamental: An essential attribute causes or explains the existence of other attributes.
Example:
The heart is an organ that goes "lub-dub, lub-dub".
The "lub-dub" sound is a superficial trait; it is merely a by-product of the heart's essential function, which is to circulate the blood.
Avoid Circularity
A circular definition tells us how a concept relates to itself, but not how it relates to other concepts or to reality. Such a definition doesn't go anywhere; it just moves in a circle.
Example:
Suppose we define "ownership" as the legal relation between people and the things they own. Because this definition uses the word "own," it defines the concept OWNERSHIP in terms of itself.
Avoid Negative Terms
A definition should not use negative terms unnecessarily.
Negative definitions should be avoided because knowing what a thing is not doesn't tell us much about what it is.
Example:
At the turn of the century, the automobile was described as a "horseless carriage." The differentia "horseless" tells us about one source of power that automobiles do not use. However, there are many sources of power automobiles do not use; what we want to know is the source they do use.
Some concepts, however, are inherently negative, and thus require negative terms in their definitions.
Example:
A "bachelor" is a man who is not married.
This has to be defined negatively, since it is an inherently negative concept.
Avoid Vagueness
This is the clarity rule. The purpose of a definition is to clarify our understanding of a concept. At the very least, therefore, the language we use in a definition should not be less clear than the concept being defined.
A vague definition is unclear because it does not give any precise criterion for membership in the concept. A definition shouldn't have borders that are even fuzzier than those of the concept being defined.
Example:
Suppose we define "maturity" as the stage of psychological development in which a person becomes well-adjusted.
Who belongs in the class of well-adjusted people and who doesn't is unclear; the class has fuzzy boundaries that are even fuzzier than those of the concept being defined.
A Definition Should Avoid Obscurity
An obscure definition is unclear because it uses abstract or technical language that is more difficult to understand than the concept itself.
Example:
Suppose we define "death" as the cessation of one's participation in finitude.
The problem here may not necessarily be one of vagueness. Within a specialized context, this definition might have a perfectly clear and definite meaning. The problem is that if technical definitions are used outside of these specialized contexts they are not clear to the layperson.
A Definition Should Avoid Metaphorical Language
A metaphorical definition is unclear because it doesn't convey the literal meaning of the concept, but only an analogy that we have to interpret.
Example:
Suppose we consider the definition: "Life is a cabaret."
Like any good metaphor, this one uses a simple image to convey a complex thought that would take many paragraphs to explain in literal terms. Metaphorical definitions leave too many questions unanswered, which is why we need literal definitions.
Functions of Definitions
Concepts serve as mental file folders that help us organize our knowledge about classes of similar things.
Definitions tell us what is in the folders.
One major function of definitions is to tell us what is and is not included in a concept, by giving us a test or rule for membership. A child who has just learned the concept of PLANT can point to some obvious and clear-cut examples of plants.
A second function of definitions is to clarify the relationships among concepts. Concepts are not isolated, self-contained units; they form networks of interrelated ideas.
A third function of definitions is to provide a summary statement about the referents of our concepts. Definitions help us keep our filing system in order by giving us summary statements about what is in each folder. A good definition condenses the knowledge we have about the referents of a concept, giving us just the highlights, the key points, the essence.
Definitions tell us what is in the folders.
One major function of definitions is to tell us what is and is not included in a concept, by giving us a test or rule for membership. A child who has just learned the concept of PLANT can point to some obvious and clear-cut examples of plants.
A second function of definitions is to clarify the relationships among concepts. Concepts are not isolated, self-contained units; they form networks of interrelated ideas.
A third function of definitions is to provide a summary statement about the referents of our concepts. Definitions help us keep our filing system in order by giving us summary statements about what is in each folder. A good definition condenses the knowledge we have about the referents of a concept, giving us just the highlights, the key points, the essence.
Monday, March 30, 2009
Conjunctions, Relative Clauses and Noun Clauses
Conjunctions, Relative Clauses and Noun Clauses
A single sentence can assert more than a single proposition.
The easiest way of combining propositions within a single sentence is to use a conjunction.
Many conjunctions assert a specific relationship between propositions.
Conjunctions like "because," "whenever," and "so that" assert a relationship of dependence.
Conjunctions like "after," "before," "since," "when," "while," and "where" assert a relationship of time or place.
Conjunctions like "but," "although," and "even though" assert a relationship of contrast or seeming opposition.
In all these cases, the conjunction combines component propositions into a statement in which all components are being asserted as true.
Relative Clauses
A clause is a grammatical unit containing a subject and a predicate.
Every sentence, therefore, contains at least one clause, but it may contain more.
A relative clause relates one clause to a particular word in another clause. A relative clause normally begins with a relative pronoun: who or whom, which, or that.
Relative clauses can be either restrictive or nonrestrictive.
A restrictive clause restricts the reference of the term it modifies (a clause).
Example:
The Japanese who eat lots of fish have fewer heart attacks.
The subordinate clause restricts the reference of the term "Japanese" to a certain subclass of the Japanese people: those who eat lots of fish.
As a result, we are making a single statement about that subclass, and we are not making any statement about the Japanese people as a whole.
A nonrestrictive clause doesn't restrict that term's reference.
Example:
The Japanese, who eat lots of fish, have fewer heart attacks.
This proposition asserts that the Japanese have fewer heart attacks and that they eat lots of fish. It makes two statements about the Japanese people as a whole.
Noun Clauses
A phrase that functions as a noun, either in the subject or the predicate of a sentence, is called a noun clause.
Noun clauses can be either asserted or not asserted within a proposition.
Compare these two sentences:
1. The president knows that war is imminent.
2. The president believes that war is imminent.
In both cases we are making an assertion about the president.
In both cases we use a noun clause, "that war is imminent," to convey what it is that the president knows or believes.
And in both cases the noun clause expresses a proposition. The difference is that sentence 1 asserts the proposition, whereas sentence 2 does not.
The English language contains a large class of verbs that we use to describe what people say and think.
We can classify these verbs on the basis of whether or not they imply the endorsement of what is said or thought.
The following verbs do not assert what is said or thought: believes, says, argues, is convinced, and suspects.
The following verbs do assert what is said or thought: knows, acknowledges, proves, is aware, and realizes.
In the study of argument, it is crucial to know whether a speaker is endorsing a given proposition as one of his or her own premises or merely reporting that someone else accepts that proposition.
Wednesday, March 11, 2009
LOGIC AND ARGUMENTS
A. LOGIC LOGIC is concerned with STANDARDS OF CORRECT REASONING.
Study of these standards may be done from two standpoints: FORMAL logic and NONFORMAL logic.
FORMAL logic is primarily THEORETICAL, and is concerned with a clear and systematic knowledge of the PRINCIPLES OF REASONING.
NONFORMAL LOGIC is primarily PRACTICAL, and is concerned with recognizing and avoiding COMMON MISTAKES in reasoning.
B. ARGUMENT The notion of an ARGUMENT is fundamental to logic. As people interested in logic we want to be able to RECOGNIZE and EVALUATE arguments.
We may define an argument as A SET OF SENTENCES CONTAINING ONE SENTENCE (CONCLUSION) WHICH IS CLAIMED TO BE PROVEN BY THE OTHER SENTENCES (PREMISES).
To understand the notion of an argument better we must first understand the notions of SENTENCE, PREMISE, and CONCLUSION.
A SENTENCE is a grammatically correct string of words which must be CAPABLE of being TRUE or FALSE.
For instance, “Ancient Athens was the first democracy,” is capable of being true or false.
But, “Was Critias a great leader?” is not.
Which of the following are sentences according to the definition just given?
Study of these standards may be done from two standpoints: FORMAL logic and NONFORMAL logic.
FORMAL logic is primarily THEORETICAL, and is concerned with a clear and systematic knowledge of the PRINCIPLES OF REASONING.
NONFORMAL LOGIC is primarily PRACTICAL, and is concerned with recognizing and avoiding COMMON MISTAKES in reasoning.
B. ARGUMENT The notion of an ARGUMENT is fundamental to logic. As people interested in logic we want to be able to RECOGNIZE and EVALUATE arguments.
We may define an argument as A SET OF SENTENCES CONTAINING ONE SENTENCE (CONCLUSION) WHICH IS CLAIMED TO BE PROVEN BY THE OTHER SENTENCES (PREMISES).
To understand the notion of an argument better we must first understand the notions of SENTENCE, PREMISE, and CONCLUSION.
A SENTENCE is a grammatically correct string of words which must be CAPABLE of being TRUE or FALSE.
For instance, “Ancient Athens was the first democracy,” is capable of being true or false.
But, “Was Critias a great leader?” is not.
Which of the following are sentences according to the definition just given?
1. Nyerere was a great statesman.
2. Bring me the vase!
3. If it is geometric, then it is pottery from the 7th Century.
4. Damn the Spartans!
5. It is not the case that Pythagoras was a Greek philosopher.
6. Which way to the Moon?
2. Bring me the vase!
3. If it is geometric, then it is pottery from the 7th Century.
4. Damn the Spartans!
5. It is not the case that Pythagoras was a Greek philosopher.
6. Which way to the Moon?
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