Logic Lesson

I taught logic and critical thinking for over forty years and while I knew neither could answer many of the deep problems we face as human beings, they always seemed to me to be a way to clarify things a bit so we might then find an answer or two.

One of the puzzles of our times is the claim we hear from time to time that “Since all great men are persecuted in their lifetime and since I am being  persecuted therefore I must be a great man.” This is what logicians call a false conversion. While we can certainly question the original claim that ALL great men have been persecuted it is none the less the case that many were. Jesus, Socrates, and Galileo leap to mind.

But even if we allow that all great men were persecuted in their lifetime (which I do not) we cannot infer that anyone who is persecuted is therefore a great man. Many a mediocre mind finds comfort in that thought, erroneous though it is. “I am being persecuted therefore I must be a great man (or woman).” Not so.

Consider these examples of false conversion:

All men are animals, therefore all animals are men.

All red-heads have quick tempers, therefore anyone who is quick-tempered is a red-head.

All triangles are geometrical figures, therefore all geometrical figures are triangles.

Bear in mind that we are not talking about whether any of those claims are true or false. Not all red-headed persons have a quick temper, for example. But we are simply asking that IF the first statement were true would the second statement follow from it? And clearly it does not. These are all what logicians call “a” propositions, universal affirmative propositions of the type All S is P, or SaP.

Therefore, just because a man or a woman is persecuted in his or her lifetime it does not follow that such a person is a genius. I can think of many who were and are persecuted in their lifetime who fully deserve it and they certainly were not geniuses. Geniuses, for example, do not spell “forest” with two “r’s.” And geniuses don’t threaten to discontinue funding FEMA since it has been found that some of the fires were started due to negligence on the part of park employees and THEN turn around and shut down the government so that Federal park employees are out of work and cannot possibly prevent fires in the future, much less improve on their past performance. Consistency is not this man’s strong suit. And consistency is a Cardinal Rule in logic and critical thinking. It is the sine qua non of genius. I’m just saying.

Once we have clarified the nuts and bolts of this particular puzzle we can move on to more important issues, such as, does such and such a person deserve to be persecuted — or at least pilloried — in his or her lifetime? As you can imagine, I can think of a couple.

 

Advertisements