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?

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?