Peter van Inwagen in undeniably one of the leading authorities on the problem of free will in the last four decades. Thinking about Free Will is a representative collection of his essays on the topic, spanning from 1978 to the present, edited by himself and with his own reflective introduction (written somewhat oddly in the third person). The essays are arranged chronologically, which allows the reader to trace the development of van Inwagen’s thought about–as well as his growing impatience with certain aspects of–the arguments surrounding free will, determinism, and the ability to do otherwise in the analytic (Anglo-American) philosophical tradition.

Van Inwagen is a defender of incompatibilism, the view that free will, which he understands as the ability to do otherwise than one does, is incompatible with determinism, the thesis that the past and the laws of nature together determine a unique future. This view is of course in conflict with compatibilism, the thesis that determinism and free will are compatible. He is rather fond of pointing out that compatibilism was the dominant view among philosophers (to the point of being very nearly unquestioned) when he came on the scene in the mid 1960’s, and that today opinions on the matter are much more evenly split, with a possible preference among specialists on free will actually tending towards incompatibilism. Undoubtedly, van Inwagen’s own arguments are partially responsible for this shift in opinion, particularly what he has called the “Consequence Argument,” his name for the standard argument for incompatibilism advanced by himself and others, including C.D. Broad, R.M. Chisholm, David Wiggins, Carl Ginet, and James Lamb. (161) Van Inwagen credits this powerful argument with the shift in opinion from compatibilism to incompatibilism in the last few decades. His own version of the argument can be stated simply as follows: There are facts about which no one has any choice (e.g. the shape of the earth, events in the distant past, etc.). It is a valid rule of inference that if p is a proposition about which no one has any choice, and if p entails q and no one has any choice about that entailment, then it follows that no one has any choice about q. Van Inwagen calls this rule “b.” If b is valid, then determinism entails that no one has any choice about anything, including things that seem as though they are within someone’s control. (There is a helpful formalized version of this argument on p. 91 of the text.)

Unfortunately, van Inwagen now believes, b is not valid, and he believes this was shown via counterexample by Thomas McKay and David Johnson in their 1996 paper “A Reconsideration of an Argument against Compatibilism.” Space prohibits me from explaining this counterexample or van Inwagen’s response to it, which is long, technical, and involves several diagrams. Suffice it to say he accepts the counterexample and goes to great pains to modify b to be able to resist it. I suspect his solution is successful, but as he himself admits, it loses the intuitive force it enjoyed in its original form. Further, it seems to me–though I cannot argue for it here–that the counterexample is in fact not successful, and that this can be shown more simply than van Inwagen does, while preserving b’s intuitive appeal. At any rate, the discussion surrounding this argument (the core of chapter 7) is fascinating and deserving of further scrutiny.

Other highlights of the text include van Inwagen’s discussion of Harry Frankfurt’s famous 1969 paper “Alternate Possibilities and Moral Responsibility,” which forms the basis of chapters 1 and 6; his critiques of Daniel Dennett’s views on free will (chapter 4 and parts of chapters 10 and 13); and the interesting argument in chapter 5 that even though incompatibilism is true, we in fact are not able to do otherwise very often–i.e. we’re free, but not very. Van Inwagen is nothing if not honest. This honesty is on display in his arguments about the inherent “mystery” of the free-will problem as well. He stops short of claiming, as some have done with other hard philosophical problems, that it is unsolvable, but he does argue forcefully that no matter which route to a solution one chooses, one is confronted with mystery. For his own part, he claims to have given up trying to solve it, and simply chooses incompatibilism as the least of the mysteries as he sees it (while eschewing so-called “agent causal” attempts at making it less mysterious).

Perhaps the most important aspect of the book are van Inwagen’s continual reminders throughout of the potential pitfalls of the language surrounding the free-will problem. These include the ambiguity of the phrase “could have” (which can mean either “might have” or “was able to”), and the meaningfulness of the phrase “free will” itself. Regarding the latter, he denies that there is a “folk concept” of free will, and that recent philosophical usage of the phrase has become so convoluted that it would be best to simply stop using it altogether. To this end, he restates his argument for incompatibilism without mentioning “free will” or similar terms at all. He also goes to great pains to reveal a confusion about the disagreement between compatibilists and incompatibilists: namely, that they are using the words “can,” “could have,” “was able to,” etc. in different ways. He argues convincingly that at least in the period in which the “free-will problem” took on its most philosophically interesting form, everyone in the debate was agreed about the meaning of these terms (or else they wouldn’t have had a philosophical disagreement at all, merely a linguistic one). He even calls the paragraph in which he argues for this the “single most important paragraph I have ever written about the free-will problem.” (82)

At times van Inwagen sounds overly pedantic, such as when he insists that no one employ “perverse” terms like “libertarian free will,” “soft determinism,” and “hard determinism.” And his identification of the mid 1960’s to the mid 1980’s as the “classical era” of the free-will problem will likely strike some readers as unnecessarily narrow. Additionally, the book would have benefitted from discussions of the relationship between free will and neuroscience, quantum mechanics, and God, all issues about which van Inwagen has expressed opinions, but which receive only brief nods in the text.

Overall, the book is a valuable contribution to the literature on free will, and will be useful to professional philosophers and graduate students (the final two previously unpublished chapters will also be of interest to specialists).

© 2017 Robert K. Whitaker

Robert K. Whitaker, PhD Candidate, Lecturer, Marquette University