The Refutation of Determinism: An Essay in Philosophical Logic by M. R. Ayers (review)

BOOK REVIEWS 191 1'he Refutation of Determinism: An Essay in Philosophical Logic. By M. R. AYERS. New York: Barnes and Noble, 1968. Pp. 179. $6.00. Readers who approach this volume anticipating a comprehensive discussion of the " free will " problem in terms of standard classical and contemporary formulations are bound to be initially disappointed. For example, scientific determinism, " the view that everything that happens is in principle explicable by reference to its antecedents and laws of nature," (p. 4) is quickly distinguished from metaphysical determinism," the denial of the existence of any free choice," (p. 4) and dismissed. There is no serious discussion of the possible ways in which the latter might depend on the former. Absent also are any discussions of the new twist given to determinist arguments by widespread acceptance of some form of the identity solution to the Mind-Body problem or recent defenses of libertarianism in terms of the now widely mooted view that intentional human actions cannot in principle be causally explained. What the book does deal with, in exhausting it not exhaustive detail, are the concepts of possibility and potentiality. And a reader who has the fortitude to press on through Ayers's thickets of dense philosophical prose will come to appreciate both the author's remark in the Preface that "perhaps everyone who can think has the concept of possibility, but no one understands it " (p. vii) and his view that clarification of the concepts of possibility and potentiality is a necessary if not a sufficient condition for refuting any deterministic arguments which have genuine implications for human freedom. The concrete argument of the book proceeds by distinguishing and clarifying three different kinds of non-logical possibility: "epistemic possibility," "natural (empirical) possibility," and "possibility for choice." Ayers's strategy is then to "try to show that the determinist charatceristically confuses different kinds of possibility, and that he misunderstands even the kinds that he recognizes." (p. 11) The author first attacks the view that the explanation of the notion of personal power (possibility for choice) is grounded in our typical inability to predict actions (epistemic possibility). His primary objection to this thesis is that the truth conditions for statements such as " It is possible for Smith to call " and " It is possible that Smith will call " are radically distinct. The first represents an " ontological " claim which depends on the facts of Smith's actual condition, while the latter embodies an " epistemic" prediction based on the evidence actually available about Smith. Neither statement entails the other, for it seems clear that the existence of Smith's capacities does not depend on what we, as a matter of contingent fact, happen to know about them. This type of argument counts equally against attempts to explain the natural capacities (empirical possibilities) of inanimate objects in terms of 192 BOOK REVIEWS concepts pertaining to what we know about them. "To say that a thing can do something is to make no sort of conjecture that it will do it, or, for that matter, that it has done it or is doing it." (p. 40) At the same time, Ayers is anxious to reject any vestige of the idea that talk about the natural powers or capacities of objects commits one to the view that they are hidden or occult properties. His own analysis of natural possibility yields the conclusion that "in general, It is possible for x to be k means In some circumstances, x would be k." (p. 69) It follows from this analysis that supporting claims about natural possibilities is a straightforward matter of gathering relevant inductive and theoretical knowledge. However, the foregoing definition of natural possibility should not be taken to imply the necessity of giving a purely conditional analysis of powers of natural objects. Indeed, Ayers's subsequent "refutation" of determinism turns precisely on this point. For he wants to maintain that neither natural possibility claims nor assertions of possibility for choice can be properly treated as elliptical conditional statements. In the case of natural possibility the argument amounts to the claim that one must distinguish between intrinsic and extrinsic conditions relevant to the attribution of capacities. The difference is illustrated by the...