At the Bryn Mawr Classical Review, philosophers Petter Sandstad and Ludger Jansen review my book Aristotle’s Revenge. From the review:
Feser’s book adds to a growing body of literature on neo-Aristotelian approaches in metaphysics and the philosophy of science. However, Feser stands out from other analytic neo-Aristotelians with his in-depth knowledge and discussion of 20th and 21st century neo-Thomistic literature, and one can learn a lot from reading this book…
The book is certainly written in an accessible style and language, which makes it readable also for undergraduate students, and even a popular audience could find much of the discussion valuable… Maybe professional philosophers will be interested in reading some of Feser’s polemics, for instance, against structural realism, reductionism, or non-presentist views of time. Finally, the book can serve as a reference point for metaphysicians and philosophers of science interested in learning about neo-Thomistic approaches in these fields… [I]t will certainly be exciting for scholars of Aristotle or Aquinas to see how these theories are used to elucidate the exciting discoveries of modern physics, biology and neuroscience.
On the book’s treatment of specific topics, they write:
Feser’s account is not a mere repristination of neo-Scholastic Aristotelianism but is also tailored to deal with current scientific ideas. Some of Feser’s discussions are of particular interest. For example, Feser’s mereological take on formal and material causation is highly original…
Another exciting topic… is that of potentiality. One idea original to the new book is that kinds of natural substances can be ordered along a scale of potentiality, according to how many potentialities they have…Highest on the scale is prime matter, which has the potential to become anything. Lower on the scale are fermions, even lower is water, and very low on the scale are, e.g., cows and other higher forms of life.
End quote. Unlike a couple of other recent reviewers, Sandstad and Jansen have no difficulty focusing on what the book is actually about:
The book is not a historical scholarly work on Aristotle; it does not discuss different interpretations of Aristotle; and it only references a couple of works by Aristotle scholars. Rather, the book is a systematic work within metaphysics, philosophy of science, and what Feser calls ‘philosophy of nature’ – which is basically a more traditional term for what is currently called ‘metaphysics of science’.
End quote. Sandstad and Jansen raise some interesting points of criticism as well. For example, commenting further on what they call the “scale of potentiality” that I say exists in nature, they write:
Feser seems not to distinguish sufficiently between potentialities, possibilities, and dispositions... In cases like the fermions, what has many potentialities has very few dispositions, while for cows or humans, it is the other way around.
End quote. This is a good point, and the distinctions Sandstad and Jansen are drawing here are very important and essential to a thorough and precise hylemorphic analysis of various kinds of substance. In fact I do develop these distinctions myself in Scholastic Metaphysics, in chapter 1 on act and potency. I do not deploy them in the specific passages on which Sandstad and Jansen are commenting, because my intention there was not to provide an analysis of cows, fermions, etc. per se, but rather to make other points.
For example, when I describe the scale of potentialities in matter in the context of discussing quantum mechanics (at pp. 312-15 of Aristotle’s Revenge), the point is to note how as we descend down the levels of physical reality, including those that feature in the micro-level description afforded by modern physics, we arrive at ever closer approximations to the notion of prime matter. When I describe the scale of potentialities in matter in the context of discussing evolution (at p. 426), the point is to note how one of the aspects of a transformist account of the origins of species might be said to be implicit in hylemorphism.
I don’t think my neglect of the distinctions Sandstad and Jansen call attention to affects the specific points I was making in passages like these. All the same, they are right to note that a fuller account of various kinds of substance would have to bring those distinctions in.
To be sure, they continue their criticism as follows:
This also points to a limitation of Feser’s idea of virtual existence: Saying that it is possible for a fermion to be part of a cow is not the same as saying that the fermion has a disposition to be part of a cow. There is a further problem. On the one hand, all ‘higher’ forms of being are already ‘virtually’ contained in prime matter – which means that there are powers in prime matter that allow for the generation of the other forms of being… On the other hand, Feser insists that substances (like fermions, copper or cats) bring with them new and irreducible powers. It is not obvious how he can resolve this tension.
End quote. I’m not certain that I see what the first problem is that Sandstad and Jansen are trying to call attention to here, but if I do understand them correctly, it seems to me that once again they may be ignoring the specific intentions I had in the passages on which they are commenting.
For example, when I say that the parts of a true substance are within it virtually (such as a fermion being virtually within an ordinary physical object), what I am trying to do is to explain ideas like the difference between substantial form and accidental form (where the parts of a thing which has only an accidental form are in it actually rather than merely virtually). I am not, in that context, offering a complete analysis of the active and passive potencies of fermions and the like in general, or of the ways that what is true of them in one context (e.g. as constituents of a cow) might not be true of them in another (e.g. outside a cow). It is perfectly true that such an analysis is important, but it just isn’t what I am concerned with in the specific passages in question. An account might be incomplete without being incorrect(as I am sure Sandstad and Jansen would agree).
Similarly, there is no conflict between the claim that various kinds of physical substance are contained potentially within prime matter, and the claim that higher forms of physical substance have powers that the lower forms lack. For we have to keep in mind the complexity that a complete account of the efficient causes of a thing has on the hylemorphic story. For a certain kind of physical substance to come into being, you need not only the presence of matter having the appropriate potencies, but also the presence of an efficient cause able to actualize those potencies. For example, a rag soaked in gasoline has the potential to catch fire, but a momentary gentle cool breeze passing over the rag won’t actualize that potential. You need another kind of efficient cause to do that.
In the same way, though there is a sense in which both copper and cats are present potentially in prime matter, different kinds of efficient cause are necessary in order to actualize those potentials. This is precisely because copper and cats have different causal powers, and those causal powers are due in part to the efficient causes of these things, and not just to their material causes. Now, in the specific passages that I think Sandstad and Jansen might have in mind here (e.g. the one at p. 426), what I am doing is, again, simply noting how part of a transformist story of the origin of species (though not the whole of such a story) lies in the hylemorphic notion of matter and the different potencies that different kinds of matter have. But I am not claiming that an appeal to the wide range of potencies present in prime matter is sufficient for a transformist story. It is not. (I do say more about what the efficient-causal side of the story would have to look like, just a little later on in the book at pp. 428-32.)
A further objection raised by Sandstad and Jansen is the following:
Another problem is that Feser often confuses the metaphysical and the epistemological aspects of science. For instance, the Aristotelian doctrines are often argued to be indispensable because the phenomena otherwise would be unintelligible… Similarly, the principle of sufficient reason is about intelligibility, rather than anything metaphysical.
End quote. Here I would certainly plead not guilty. For one thing, I simply reject Sandstad’s and Jansen’s assertion that the principle of sufficient reason (PSR) has no metaphysical significance. Indeed, PSR plays such a central role in rationalist and Neo-Scholastic metaphysics that it is surprising that Sandstad and Jansen would make this assertion so flatly, without at least acknowledging that their opponents are bound to regard it as tendentious or even question-begging.
Recall that in the view of Thomists and other Scholastics, being and truth are both transcendentals, and thus convertible. Truth is just being considered as intelligible, and given the convertibility of the transcendentals we can infer that anything that has being must accordingly be intelligible – in which case PSR has metaphysical significance. It tells us the way reality is, not just how we have to think about it. (For further discussion, see my treatment of PSR at pp. 137-46 of Scholastic Metaphysics.)
Offering examples of my alleged conflation of metaphysics and epistemology, Sandstad and Jansen write:
[I]n his discussion of reduction in chemistry, Feser argues that the identification of the lower levels presupposes a prior grasp of the higher levels... Further, Feser accepts Locke’s point that “real essence, you might say, ‘piggybacks’ on nominal essence”… But, this dependence seems to be merely epistemological, namely to know the real essence of a thing one must first know its nominal essence.
End quote. But in fact, the points I am making in these passages are by no means merely epistemological. When critics of reductionism in chemistry note that the micro-level phenomena the reductionist focuses on are unintelligible apart from the macro-level description, the point is that the micro-level phenomena simply wouldn’t exist in the specific way they do apart from the macro-level facts. It isn’t merely the epistemological point that we wouldn’t know about the former apart from the latter. It is a deeper, metaphysical point to the effect that the former wouldn’t objectively be there in the first place apart from the latter. Indeed, it is this deeper, metaphysical fact that explains the epistemological situation.
Similarly, the point about Locke is that unless there really were something objectively out there that corresponded to the nominal essence (of gold, say), there just wouldn’t objectively be a real essence (the chemical facts about gold) of the kind that we in fact find to be correlated with that nominal essence.
All the same, the relationship between the metaphysical and epistemological considerations here is an important issue, and perhaps one that I should have addressed more thoroughly so as to forestall objections like the one Sandstad and Jansen raise.
Though it is not clear that it is meant as a criticism, Sandstad and Jansen also write:
[W]hile Feser occasionally criticises theories in the current literature (such as Ladyman’s ontic structural realism), he more often engages with older views, such as the early moderns, or logical positivism, or Russell and Quine; or literature from the 80s and 90s.
As a result, it is not easy to identify the intended audience.
End quote. Now, I don’t know why it would be mysterious who my intended audience is, because I think that should be clear not only from the content of the book, but from the preface and indeed the back cover copy. The book is about the relationship between modern science and the Aristotelian-Thomistic tradition in metaphysics, and it interacts with the literature in contemporary metaphysics and philosophy of science that elucidates that relationship. Its intended audience, then, includes anyone who might be interested in this topic, such as analytic philosophers who are interested in the current neo-Aristotelian revival in metaphysics, Thomists who are curious about what is going on in analytic philosophy, or people working in ethics or philosophy of religion curious about how the metaphysical assumptions underlying ideas like traditional natural law theory or Scholastic natural theology might be defended in light of modern science.
I’m also not clear why it is odd that I would treat the “older views” referred to by Sandstad and Jansen. For example, to understand the dispute between the Aristotelian and mechanistic conceptions of nature, you have to know something about the early modern origins of that dispute. To understand why it is of great importance whether special relativity presupposes verificationism, you have to know something about the many grave problems raised against verificationism by critics of logical positivism. To understand the nature and implications of epistemic structural realism, you need to know something about Russell’s version of that view and the debate it engendered. And so on. Everything I put into the book is meant to play some role in furthering its overall project. Whether some of these issues and ideas are “older” or not much discussed by contemporary writers seems to me irrelevant. Indeed, part of my point is that they should be more discussed.
But I don’t want to make more of this issue than Sandstad and Jansen themselves do. And I thank them for their kind words about the book and for their thoughtful and stimulating criticisms.