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.

 

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6 thoughts on “Logic Lesson

  1. Hello Hugh,

    I submitted a comment earlier here, though I am not sure why it has disappeared. Here’s my second attempt.

    I enjoyed reading your recounting of your teaching logic and critical thinking for four decades.

    My own contribution in this regard can be found in the section called “Logic versus Fame: Formal Fallacy, Genetic Fallacy, Halo Effect” of my post at http://soundeagle.wordpress.com/2017/10/18/the-quotation-fallacy/#Logic_versus_Fame

    May you have a wonderful weekend enjoying what you love doing the most!

  2. Yes, I agree with you that the competent grasp and use of logic are very important and highly conducive to conducting proper discussion or research.

    I also discuss classical logic in the section called “Classical Logic: Contradiction, Context, Scope, Validity, Generalizability” of my post at http://soundeagle.wordpress.com/2017/10/18/the-quotation-fallacy/#Classical_Logic

    I would really appreciate it if you could give me some feedback at the comment section of my post regarding the two said sections. 🙂

    • I couldn’t find a box on your post to respond. I would say “well done,” and would only add that in formal logic (of which I write) context is irrelevant. Your post has more to do with critical thinking than logic, strictly speaking. But it is most interesting. Many thanks.

      • Hi Hugh,

        The comment section is at the very bottom of the post. I look forward to receiving your feedback there. Please be informed that you might need to use a desktop or laptop computer with a large screen to view the rich multimedia contents available for heightening your multisensory enjoyment at my websites, some of which could be too powerful and feature-rich for iPad, iPhone, tablet or other portable devices to handle properly or adequately. A fast broadband connection is also helpful. 🙂

  3. You have offered a brief and important lesson on the logical analysis of some statements. Would that the psychological analysis of those same statements were as straightforward.😎

    Regards,

    Jerry Stark

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