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Summa Philosophica QUOTES

Summa Philosophica QUOTES

1 " Article 10: Whether symbolic logic is superior to Aristotelian logic for philosophizing?

Objection 1 : It seems that it is, for it is a modern development, and would not have become popular if it were not superior. In fact, 99% of all formal logic textbooks in print today use symbolic rather than Aristotelian logic.
Objection 2: It is as superior in efficiency to Aristotelian logic as Arabic numerals to Roman numerals, or a computer to an abacus.
Objection 3: Aristotelian logic presupposes metaphysical and epistemological realism, which are no longer universally accepted. Symbolic logic is ideologically neutral. It is like mathematics not only in efficiency but also in that it carries less “philosophical baggage.”

On the contrary , the authority of common sense is still on the side of Aristotelian rather than symbolic logic. But common sense is the origin, basis, and foundation of all further refinements of reason, including symbolic logic; and a branch should not contradict its trunk, an upper story should not contradict its foundation. All philosophical systems, including symbolic logic, since they are refinements of, begin with, and depend on the validity of common sense, even while they greatly refine and expand this foundation, should not contradict it, as symbolic logic does. (See below.)

I answer that at least two essential principles of symbolic logic contradict common sense: (1) the counter-intuitive “paradox of material implication,” according to which a false proposition materially implies any proposition, false as well as true, including contradictories (see Socratic Logic , pp. 266-369); and (2) the assumption that a particular proposition (like “some elves are evil”) claims more, not less, than a universal proposition (like “all elves are evil'’), since it is assumed to have “existential import” while a universal proposition is assumed to lack it, since symbolic logic assumes the metaphysical position (or “metaphysical baggage”) of Nominalism. See Socratic Logic , pp. 179-81, 262-63 and The Two Logics by Henry Veatch. Furthermore, no one ever actually argues in symbolic logic except professional philosophers. Its use coincides with the sudden decline of interest in philosophy among students. If you believe that is a coincidence, I have a nice timeshare in Florida that I would like to sell to you.

Reply to Objection 1: Popularity is no index of truth. If it were, truth would change, and contradict itself, as popularity changed — including the truth of that statement. And thus it is self-contradictory.

Reply to Objection 2: It is not more efficient in dealing with ordinary language. We never hear people actually argue any of the great philosophical questions in symbolic logic, but we hear a syllogism every few sentences.

Reply to Objection 3: Symbolic logic is not philosophically neutral but presupposes Nominalism, as shown by the references in the “/ answer that ” above. "

― Peter Kreeft , Summa Philosophica