There is a condescending Tweet going around from some guy who describes himself as “a radical skeptic” who “follows the laws of dialectic” attempting to demonstrate the foolishness of philosophy (compared to science, as if they’re in competition?) by — and I kid you not — promoting a formally invalid syllogism and thinking this means something. Have a look.
Intuitively, people can tell the conclusion doesn’t follow from the premises, even if they aren’t able to identify why. It is that intuition that may seem to give Cooper’s Tweet force, but only inasmuch as somebody is ignorant enough to think his syllogism is valid in the first place, which it isn’t. Had Mr. Cooper taken the time to enroll in an elementary philosophy course (logic 101, say) then it would be made obvious to him why his proposed defeater of philosophy fails, and that is because he commits the formal fallacy of Illicit Major.
Simply put, the fallacy of Illicit Major occurs when the major term is undistributed in the major premise but distributed in the conclusion. (Here’s an overview.) The fallacy follows the form:
All (a) are (b)
No (c) are (a)
Therefore, no (c) are (b)
Parallel example:
All philosophers are intelligent.
Paul Cooper is not a philosopher.
Therefore, Paul Cooper is not intelligent.
Of course, one can challenge the TRUTH of the premise “all philosophers are intelligent” to defeat the argument, and it is obviously the case that not ALL philosophers are intelligent, though I’m not going to argue that now. However, IF — if, if, if! — all philosophers WERE intelligent and Paul Cooper WERE not a philosopher, the conclusion would still fail to follow, because in the major premise intelligence is undistributed, meaning we are making a statement only about SOME things which are intelligent — namely, they are philosophers — but not ALL things that are intelligent. Conversely, intelligence is distributed in the conclusion because we are making a statement about ALL things which are intelligent: namely, none are Paul Cooper. The point is maybe Paul Cooper is intelligent, maybe Paul Cooper is not intelligent, but we are not going to learn that one way or another from the syllogism above. Mutatis Mutandis with the Socrates example.
Followers of my logic series on the podcast know I have recommended Kreeft’s book Socratic Logic as a great beginner logic text, and those who’ve studied the book (and practiced their Euler Circles!) would have been able to detect what’s wrong with Cooper’s example in a jiffy.
But it gets worse. Rather than backing down from his idiotic assertion (apparently, Cooper is only skeptical of other people’s thoughts — including some of the most brilliant minds in history — but never his own, as so many self-proclaimed “radical skeptics” tend to be) he doubles down, saying,
Generally speaking — and call this nitpicking if you want, but it’s important to point out even the subtle inaccuracies of someone making such a confident but false claim — something isn’t logically “sound,” since being SOUND (versus unsound) is a quality of arguments only when the logic is VALID (versus invalid) and the premises are TRUE (versus false).
OK, enough!