Aristotle’s Revenge: The Metaphysical Foundations of Physical and Biological Science

by Edward Feser

The central argument of this book is that Aristotelian metaphysics is not only compatible with modern science, but is implicitly presupposed by modern science.

place. I am talking about the philosophical ideas that can be disentangled from this outdated scientific framework, such as the theory of actuality and potentiality and the doctrine of the four causes.

I am arguing that the practice of science, and the results of science at least in their broad outlines, implicitly presuppose the truth of these ideas, even if for most practical purposes the scientist can in his ordinary work bracket them off.

In any event, early modern critics of the Aristotelian philosophy of nature thought of themselves as replacing an “organic” conception of the world with what has been called a “mechanical philosophy,” a “mechanistic” conception of nature, or a “mechanization” of the world. That is to say, they took the notion of the machine rather than that of the organism to be the best model for nature in general. (Cf. Dear 2006, pp. 15-16)

The mechanical conception was rather a philosophical account of how best to carry out scientific investigation and/or to interpret its results. It is a methodological-cum-metaphysical theory about science, rather than strictly a part of science.

principle of sufficient reason (PSR).

Now, structural realism is precisely the brand of realism I would defend

What I do claim is merely that, to the extent that physics or any other science confines itself to an abstract mathematical description of nature, it cannot give us complete knowledge of concrete physical reality, and that the more abstract the description, the less complete it is.

I am proposing that, in a similar way, the abstract mathematical structure of nature described by physics and other sciences does not exist qua abstract mathematical structure in mind-independent reality. Rather, it exists there only in a concrete natural order which has various features that go beyond the ones that can be captured in the mathematical description

than a kind of nominalism or conceptualism. But just as Aristotelian realism about universals is not Platonic realism, neither does the structural realism I advocate hold that structure exists or can exist on its own, apart from concrete individual things.

Ontic structural realism makes a much bolder claim. It holds that there is nothing more to the natural world than the structure revealed by physics or other sciences.

Ontic structural realism cannot be correct,

I have argued that the existence of the experiences and cognitive processes of the conscious embodied subject entails the existence of change and thus of the actualization of potentiality, of final and efficient causality, and of substantial form and prime matter. Since all of that goes beyond what is captured in a description of the mathematical structure of nature, what has been said in earlier chapters suffices to show that there is more to the world than such structure.

There must be relata which are related by the mathematical relations described by physics.

Ontic structural realism essentially blurs the distinction between the concrete and the abstract, between physics and mathematics. But even scientists who emphasize the role of mathematics in physics acknowledge the difference.

Now, as we saw in chapter 3, for neo-Aristotelians like Cartwright, laws of nature are not universal, and they are not ontologically fundamental. What are fundamental are the natures and capacities of things, and laws describe how a thing will behave given its nature and capacities, not necessarily universally but under certain conditions. Natures and capacities (and thus laws, rightly understood) are immanent to things rather than standing above and apart from them like Platonic forms or divine decrees.

the hylemorphic account of the relationship between prime matter and fundamental particles,

All the elementary particles are made of the same substance, which we may call energy or universal matter; they are just different forms in which matter can appear. If we compare this situation with the Aristotelian concepts of matter and form, we can say that the matter of Aristotle, which is mere “potentia,” should be compared to our concept of energy, which gets into “actuality” by means of the form, when the elementary particle is created. (2007, p. 134)

One might perhaps call it an objective tendency or possibility, a “potentia” in the sense of Aristotelian philosophy. In fact, I believe that the language actually used by physicists when they speak about atomic events produces in their minds similar notions as the concept “potentia.” So the physicists have gradually become accustomed to considering the electronic orbits, etc., not as reality but rather as a kind of “potentia.” (pp. 154-5)

The probability wave of Bohr, Kramers, Slater… was a quantitative version of the old concept of “potentia” in Aristotelian philosophy. It introduced something standing in the middle between the idea of an event and the actual event, a strange kind of physical reality just in the middle between possibility and reality. (p. 15)

It must also be emphasized that objections to the principle of causality which appeal to quantum mechanics are, ultimately, appeals to laws of physics. But as we saw in earlier chapters, for the Aristotelian, a law of physics is essentially a shorthand description of the way a thing will behave given its nature or substantial form. Thus, to explain something in terms of the laws of physics is hardly an alternative to explaining it in terms of the actualization of a potential. For the substantial form of a physical substance relates to the substance’s prime matter as actuality to potentiality. In particular, the substantial form is what actualizes the potentiality of prime matter to be a substance of such-and-such a kind. In that way, the operation of any laws of nature, including the laws of quantum mechanics, presupposes the actualization of potential.

In the case of human rationality, the traditional Aristotelian view is that we do have a phenomenon that is not merely irreducible to lower forms of life, but is incorporeal.

Having made this distinction, Dembski goes on explicitly to acknowledge that just as “the art of shipbuilding is not in the wood that constitutes the ship” and “the art of making statues is not in the stone out of which statues are made,” “so too, the theory of intelligent design contends that the art of building life is not in the physical stuff that constitutes life but requires a designer” (p. 133, emphasis added). In other words, according to Dembski, living things are for ID theory to be modeled on ships and statues, the products of techne or “art,” whose characteristic “information” is not “internal” to them but must be “imposed” from “outside.” But that entails that they have only accidental rather than substantial forms, and only extrinsic rather than intrinsic teleology. And as we saw in chapter 1, reconceiving of natural objects (living or otherwise) in these terms is precisely how the mechanistic world picture departed from the Aristotelian philosophy of nature.