What Is Logic? And Why Should You Care?

Great question. Logic is the art and science of correct thinking, in which one may deduce truths which are unknown from ones we already do know by following the steps of implication from stated premisses.

There are by now many different kinds of logic. These go by impressive sounding names like informal logic, and formal, predicate, mathematical, sentential, symbolic, modal and others. The list runs fairly long. The reason for this stems from the fact that the Greeks were doing logic self-consciously since Aristotle and before. This makes for more than 2,300 years of logic-doing.

If you simply pick out a book on symbolic logic from the outset, you will get very intimidated. Don't do this. If you flop open the book to just any page (ignoring my good advice), you will see an alphabet soup of Greek letters strung together connected by functions and operators -- which look just as weird.

It's pretty much "Greeks gone wild" at first glance. Later, just as when you learn any new language (logical systems are better described as "language games" for the record, but that's techie stuff. For now we will use the metaphor or analogue of language. Only practice and learning makes the unintelligible more sensible, and this takes time and effort like anything else. But it can be done.

Start first with informal logic. This is crazy enough because you learn how to reason well by studying fallacies (the substance of informal logic texts) -- which show you how NOT to reason well. This would be like teaching a guy to swim by showing him how people can drown in a dozen different settings. This shows that even logicians suffer from the Adamic fall. It goes straight to the head, so it's called the noetic effect of sin ("nous" is Greek for mind, which corresponds to "mentis" in Latin). On occasion, I'll toss in the Greek and Latin tidbits to help build a better vocabulary along the way. Vocabulary building is in itself a great reason to learn logic.

Nevertheless, even though the teaching methods and heuristic devices employed by informal logic need serious reformation, the material does in fact aid one in identifying errors and what they look like so you know the pitfalls to avoid and can spot them when others commit them, so you don't get easily sold a false view. Error detection -- which is really what informal logic amounts to -- has very important uses for the Christian. Christians are to expose error for what it is, and this is a great place to begin learning just how to go about this.

For my first exercise, I am recommending that teachers here ask their students to scour what they know of the Bible in their minds, and come up with 5 good reasons for what good use a Christian may make of identifying errors in reasoning.

I'll start you off with number one. Logic has a direct relationship to the TRUTH, which is of ultimate concern -- this is not the art and science of fanciful thinking (that's called "evolution"); this is the art and science of correct thinking. By identifying errors one may better understand the nature of the truth, by eliminating some candidates from the ring of "possibly true" ideas. This narrows the field by deduction and helps one learn the "good and necessary" consequences of this or that proposition.

Okay, now it's your turn boys and girls. Four more. Have fun.