Musings on “The Lost Tools of Learning” #2
In defending the teaching of Formal Logic, Dorothy Sayers notes, “Another cause for the disfavor into which Logic has fallen is the belief that it is entirely based upon universal assumptions that are either unprovable or tautological. This is not true. Not all universal propositions are of this kind.”
I want to make two comments. First, it appears that Sayers is committing the fallacy of apriorism here. The discreditors of Logic attack it by arguing that the universal assumptions upon which Logic is based are unprovable or tautological (and are thus worthless). She implies, in what appears to be a hasty generalization, that they are attacking all universal propositions (when she argues that not all universal propositions are of this kind), when in fact they are only attacking some of them. Maybe I am missing something here, but it seems that the universal propositions she defends may not be the same ones the discreditors are attacking.
Second, if I were to respond to the discreditors given her assumption, I would argue this way: “Do you really believe that all universal propositions are unprovable or tautological? Then how about that claim? Is it unprovable, or tautological?” All universal propositions are unprovable or tautological is itself a universal proposition, and is thus open to the same refutation. Thus this attack on universals lays itself wide open to a classic reductio.
It would be an instructive exercise to take Logic or Rhetoric students through a defense of Sayers claim that not all universal propositions are unprovable or tautological. Ask your students, “How do we know the truth of universal propositions?” Discuss the value of an inductive defense of universals. Discuss also the proving of universals by authority, by definition, and by deduction from other universals.
Tags: Sayers