Frege's Logic

Before Frege, there was logic in the Aristotelian sense. The textbook example of Aristotelian logic is:

Fact: All men are mortal.

Fact: Socrates is a man.

Conclusion: Socrates is mortal.

While this logic has its uses, it does not make a conclusion that is anything more than an abridged form of the two facts. Another example would be:

2 + 2 + 2 = 6, therefore 2 x 3 = 6

The second equation is the same as the first, but it's more concise. This is the only result of Aristotelian logic.

Frege devised a system of analysing language which replaced subject and predicate with function and argument.

Traditionally, in the sentence 'Wellington defeated Napoleon', 'Wellington' is the subject and 'defeated Napoleon' is the predicate. Frege would have 'Wellington defeated' be the function, the unchanging part of the sentence and 'Napoleon' as the argument, which can be changed to a true or false statement (e.g., 'Wellington defeated Napoleon' is true, but 'Wellington defeated Nelson' is false.)

There's more to Frege's technical new language of logic, but the essential basis is to root out the meaningless language and present only fact; the perfect language would be binary code, a series of 1s and 0s, true and false. Frege's importance comes through most of all in computer programming, as logic becomes its basis - computers and programs essentially run on a series of true/false statements.

Later on in life Frege came to consider the other aspect of language, 90% of it that is pure fluff; what he calls 'colour'. Colour is the descriptive, evocative language we use to understand the world on an emotional/personal level, where logic is more impersonal.