IN his latest book, The Trouble with Principle,† Stanley Fish claims to be an heir to the classical tradition of rhetoric.  His self-proclaimed antecedents are the pre-Socratics, the rhetorics of Aristotle, Cicero, and Quintilian, the politics of Castiglione and Hobbes, the pragmatism of James, Dewey, and Rorty, the speech-act theory of J. L. Austin, and, above all, the political outlook of Machiavelli. With his customary reserve, he identifies his liberal adversaries with Milton’s Satan (“the authentic voice of technological modernism”) and himself with Augustine.