Paradox of Self-Amendment by Peter Suber Our fundamental principle is that whenever a question can be decided by logic at all it must be possible to decide it without more ado. (And if we get into a position where we have to look at the world for an answer to such a problem, that shows that we are on a completely wrong track.) Ludwig Wittgenstein, Tractatus Logico-Philosophicus, Routledge & Kegan Paul, 1969 (original 1921), 5.551. Note that several philosophers have argued, on the contrary, that experience can conflict with belief, and that we always have a choice whether to change our beliefs in the face of such experience or to change the logic that defines the conflict as a contradiction. This position asserts that logic is mutable, or at least deniable, in light of experience. See W.V.O. Quine, "The Two Dogmas of Empiricism," in his From a Logical Point of View, Harvard University Press, 1953, pp. xiv and 43, and his Methods of Logic, rev. ed. 1959, p. xiv; Israel Scheffler, Science and Subjectivity, Bobbs-Merrill, 1967, pp. 115-16; Paul K. Feyerabend, "How To Be A Good Empiricist," in P.H. Nidditch (ed.), The Philosophy of Science, Oxford University Press, 1968, pp. 12-39; Hilary Putnam, "Is Logic Empirical?" in R.S. Cohen and M.R. Wartofsky (eds.), Boston Studies in the Philosophy of Science, vol. V, Reidel Pub. Co., 1969, p. 216; Susan Haack, Deviant Logic: Some Philosophical Issues, Cambridge University Press, 1974, pp. 25-46. This position has been criticized by Carl R. Kordig, "Some Statements Are Immune to Revision," The New Scholasticism, 56 (1981) 69-76, and Elliott Sober, "Revisability, A Priori Truth, and Evolution," Australasian Journal of Philosophy, 59 (1981). I might add, for the purposes of this discussion, that the "mutability" thesis may be construed to emphasize the optional character of logical rules without denying their (conditional) eternality. In short, the mutability of logical rules, even in the opinion of those who think logical rules are subject to revision in the light of experience, is not the same as the mutability of legal rules. The paradox of self-amendment cannot arise in logic because no logical rules of any logical system authorize one (logician, critic, dissenter, incendiary, subject of anomalous experiences) to change other rules of the system. Even dialectical logics, which contain changing rules, contain no rules that authorize change on the decision of human agents. No logical system tolerates such license in the logician, or tolerates meddling in real time with valid rules according to alogical standards. Legal systems are fundamentally different in this regard, and this difference must be kept in mind to prevent an oversimplified, logicized concept of law. 18. The best article on legal omnipotence is Ilmar Tammelo, "The Antinomy of Parliamentary Sovereignty," Archiv für Rechts- und Sozialphilosophie, 44 (1958) 495-513, which is immediately followed by a commentary by Jaakko Hintikka, "Remarks on a Paradox," ibid., 514-16. See also Geoffrey Marshall, Parliamentary Sovereignty and the Commonwealth, Oxford University Press, 1957, passim, and his "Parliamentary Sovereignty and the Language of Constitutional Limitation," Juridical Review, 67 (1955) 62. See also Zelman Cowen, "Parliamentary Sovereignty and the Limits of Legal Change," Australian Law Journal, 26 (1952) 237-40; Sir William Ivor Jennings, The Law and the Constitution, University of London Press, 3d. ed., 1943, pp. 142-45, 148-53; and H.L.A. Hart, The Concept of Law, Oxford University Press, 1961, pp. 64-76, 144-50. See the literature that has grown up around the famous English case, London Street Tramways Co. v. London County Council, (1898) A.C. 375, (discussed in Section 15.B below) in which the House of Lords settled a long unsettled question and limited its own power by declaring that it is bound by its own decisions and can, to that extent, decide to limit itself further in the future. The case presents the paradox of omnipotence sharply, but also the paradox of supporting, through the rules of stare decisis, the principle that stare decisis binds the House of Lords. See e.g. Salmond on Jurisprudence, Sweet & Maxwell, 11th ed. by Glanville Williams, 1957, pp. 186-88, 519-24, and the 12th ed. by P.J. Fitzgerald, 1966, pp. 21-28; A.W.B. Simpson, "The Ratio Decidendi of a Case and the Doctrine of Binding Precedent," in A.G. Guest (ed.), Oxford Essays in Jurisprudence, Oxford University Press, 1961, Chapter VI. On the equally paradoxical overruling of London Tramways see e.g. John H. Langbein, "Modern Jurisprudence and the House of Lords: The Passing of London Tramways," Cornell Law Review, 53 (1968) 806-13. 19. The leading essay is J.L. Mackie, "Evil and Omnipotence," Mind, 64 (1955) 200-12, revised in his "Omnipotence," Sophia, 1 (1962) 13-25. See also, in roughly chronological order, S.A. Grave, "On Evil and Omnipotence," Mind, 65 (1956) 259-62; I.T. Ramsey, "The Paradox of Omnipotence," Mind, 65 (1956) 263-66; P.M. Farrell, "Evil and Omnipotence," Mind, 67 (1958) 399-403; G.B. Keene, "A Simpler Solution to the Paradox of Omnipotence," Mind, 69 (1960) 74-75; Bernard Mayo, "Mr. Keene on Omnipotence," Mind, 70 (1961) 249-50; G.B. Keene, "Capacity-Limiting Statements," Mind, 70 (1961) 251-52; George I. Mavrodes, "Some Puzzles Concerning Omnipotence," Philosophical Review, 72 (1963) 221-23; Harry G. Frankfurt, "The Logic of Omnipotence," Philosophical Review, 73 (1964) 262-63; Armando F. Bonifacio, "On Capacity Limiting Statements," Mind, 74 (1965) 87-88; G. Schlesinger, "Omnipotence and Evil: An Incoherent Problem," Sophia, 4 (1965) 21-24; Sidney Gendin, "Omnidoing", Sophia, 6 (1967) 17-22; L. Wade Savage, "The Paradox of the Stone," Philosophical Review, 76 (1967) 74-79; James Cargile, "On Omnipotence," Nous, 1 (1967) 201-05; George F. Englebretsen, "The Incompatibility of God's Existence and Omnipotence," Sophia, 10 (1971) 28-31, with comments by David Londey, Barry Miller, and John King-Farlow; P.T. Geach, "Omnipotence," Philosophy, 48 (1973) 7-20; Richard Swineburne, "Omnipotence," American Philosophical Quarterly, 10 (1973) 231-37; Jerome Gellman, "The Paradox of Omnipotence and Perfection," Sophia, 14 (1975) 31-39; Paul Helm, "Omnipotence and Change," Philosophy, 51 (1976) 454-61; Edward J. Khamara, "In Defense of Omnipotence," Philosophical Quarterly, 28 (1978) 215-28; Joshua Hoffman, "Mavrodes on Defining Omnipotence," Philosophical Studies, 35 (1979) 311-13; Bruce R. Reichenback, "Mavrodes On Omnipotence," Philosophical Studies, 37 (1980) 211-14; Gary Rosenkrantz and Joshua Hoffman, "What An Omnipotent Agent Can Do," International Journal for Philosophy of Religion, 11 (1980) 1-19; Loren Meierding, "The Impossibility of Necessary Omnitemporal Omnipotence," International Journal for Philosophy of Religion, 11 (1980) 21-26. 20. This formulation of the paradox is probably vulnerable to time-based objections (see Section 10) which a more sophisticated formulation (Section 3) would succeed in evading. 9