What Is the Philosophy of Nature? Review of Feser’s Aristotle’s Revenge

By John G. Brungardt

Edward Feser, Aristotle’s Revenge: The Metaphysical Foundations of Physical and Biological Science (Neunkirchen-Seelscheid: Editiones Scholasticae, 2019).

The bad thing with Thomistic metaphysics is that it implies the possibility of a philosophy of nature. (Yves Simon, The Great Dialogue of Nature and Space, p. 17)

Before the term was coined by William Whewell in 1833, “scientists” were called “natural philosophers.” The different names have come to mark the difference between what “scientists” and “philosophers of nature” are supposed to be about. To “philosophize about nature” now connotes a pursuit of abstract, metaphysical claims that are beyond concrete empirical tests. It is a pursuit of indefinite knowledge.

As Descartes quips, “The learned all know that there is nothing in Scholastic Physics which is not doubtful, and they also know that in such matters being doubtful is little better than being false, for a science must be certain and demonstrative.” If “philosophy, like all other studies, aims primarily at knowledge,” there is still this that divides it from the sciences, claims Bertrand Russell, namely that “as soon as definite knowledge concerning any subject becomes possible, this subject ceases to be called philosophy, and becomes a separate science.” Philosophy is successful only in its self-destruction. The modern natural sciences, and especially mathematical physics, impose their own version of “secularism.” Philosophical and metaphysical claims are relegated to the arena of one’s own private views. By contrast, what is common to all—and so what can count as objective, definite knowledge—are those conclusions subject to the publicly verifiable evidence, procedures, and calculations of the sciences.

Natural philosophy, on this view, would be that body of indefinite knowledge that became the parent of our various objective, definite natural sciences. The children are now grown up, moved out, and have relegated their father to the retirement home sector of academia. What the philosophy of nature can now give us is not wisdom, but boring, irrelevant, and out-of-date personal tales about nature.

Even those who would take issue with this state of affairs invest the term “natural philosophy” with a variety of names and rationales. What is worse, the late 19th- and early to mid 20th-century revival of “Scholastic natural philosophy” took decades to come to grips with the progress of the modern sciences since Galileo. No deep consensus on how to do so emerged, except the realization that, as Simon puts it, “the bad thing with Thomistic metaphysics is that it implies the possibility of a philosophy of nature.”

Edward Feser’s Aristotle’s Revenge (Editiones Scholasticae, 2019) is consequently a welcome addition to the late 20th- and early 21st-century resurgence of broadly Aristotelian and Thomistic approaches to the philosophy of nature, and the volume spells out in detail and begins to develop the metaphysical grounds to which Simon refers. It is essential reading for those interested in the topic of the perennial Aristotelian philosophy of nature and its relationship to the particular natural sciences.

Feser argues that, with the rise of modern science, many “have been too quick to throw the Aristotelian metaphysical baby out with the physical bathwater” (Aristotle’s Revenge, 222). Aristotle’s revenge consists in the fact that his philosophy of nature is both compatible and “implicitly presupposed by modern science” (1; and, e.g., 19–20, 64–65, 74, 137–138, 305). Not only do the sciences—e.g., physics, chemistry, biology, or neuroscience—need this philosophy of nature (in a sense to be specified), but the scientist also needs it in order to have a coherent and sound understanding of the possibility of his very practice of science. To defend such broad, substantive claims, Feser crafts a broad, substantive book, concluding that

Thus does Aristotle have his revenge against those who claim to have overthrown him in the name of modern science. But he is a magnanimous victor, providing as he does the true metaphysical foundations for the very possibility of that science. (456)

Let us sketch the route that Feser takes to the conclusion.

Feser’s Preface immediately sets down the thesis of the book: “Aristotelian metaphysics is not only compatible with modern science, but is implicitly presupposed by modern science” (1). He is just as quick to qualify that this means Aristotle’s “metaphysical ideas rather than [his] scientific ones. Or to be more precise, they are ideas in the philosophy of nature, which I regard as a sub-discipline within metaphysics” (ibid.). Feser’s aim, then, is not to defend outmoded Aristotelian physics (natural place is a typical example: ibid., and 222, 230, 329), nor to propose ideas or concepts that scientists must use and be guided by when they go about their daily work, but to defend the principles that scientists and their sciences implicitly rely upon and by which one can interpret the results of the sciences.

Thus, the sound self-understanding of scientific practice and a defense—as the case may be—of the coherency, plausibility, or truth of broadly Aristotelian foundations for and interpretations of scientific results are the two paramount aims of the book and structure its contents. The scope is purposefully general, and Aristotle’s Revenge means to encourage future work. And I indeed hope that it does!

The main matter of the book is divided into two parts. Chapter 1 is Feser’s account of what the Aristotelian philosophy of nature is and what its principal claims are (the latter is a recapitulation drawing on Feser’s Scholastic Metaphysics). This philosophy of nature stands in contrast with its chief rival, the mechanical philosophy of nature. The remaining chapters subsequently articulate and defend key Aristotelian claims in the context of an analysis of the modern natural sciences.

This analysis does “not [pit] philosophy of nature against physics” or, more generally, the sciences, but “[pits] one philosophy of nature against another philosophy of nature” (305). Feser aims to show “how both the practice and the results of natural science are not only in no way incompatible with these Aristotelian theses, but in many cases presuppose their truth” (64). Chapter 2 takes up the subject of the practice of the natural sciences; Chapter 3–6 discuss the interpretation of their results.

Thus, in Chapter 2, Feser argues that the principles of the Aristotelian philosophy of nature are necessarily implied in the scientist’s own practice of science. Indeed, he claims, the basic assumptions of the scientific method that philosophers of science tend to agree on “presuppose an essentially Aristotelian conception of nature (whether most philosophers of science realize this or not)” (65). In short, there is no “view from nowhere” from which one obtains the scientific understanding of the universe. The scientist as subject, an embodied knower, cannot be ignored, and “the reality of the subjective point of view of the scientist cannot be made sense of without deploying the central notions of the Aristotelian philosophy of nature” (137).

Feser then turns to discuss the results of the various natural sciences, to see whether they invalidate key Aristotelian principles, and to determine what light Aristotelian metaphysics can shed. To clear the way forward, he first argues in Chapter 3 that the sciences—and in particular the empiriometric sciences, such as physics—do not capture all there is to the natural world. Here, Feser adopts an Aristotelian variety of epistemic structural realism, the natural complement to his claims that the sciences do not provide “an exhaustive picture of nature” (139). Thus, within the argumentative strategy of his book, this opens up the logical space necessary for the Aristotelian philosophy of nature to say something positive about the world.

After eliminating verificationism, falsificationism, and “naturalized metaphysics” as possibilities for interpreting the empirical basis of knowledge about nature, Feser examines the explanatory core of the sciences. In its paradigmatic form, this core is empiriometric. A closer inspection “[reveals] that in fact [empiriometric theories] tell us relatively little about the natural world” (151). What Feser means by “empiriometric” is more or less means what Jacques Maritain meant by the term: the non-ontological but empiriological study of natural phenomena that employs a mathematically principled explanatory method (see Maritain 1946, 265ff).

The negation of the sciences’ claim to exhaustively describe nature is appropriately followed up by a positive deployment of the general Aristotelian theses sketched in Chapter 1. Their defense, application to, and thus the interpretation of the results of the modern sciences touches on Newtonian physics, relativity, quantum theory, chemistry, biology, and neuroscience. In order, Chapter 4 is broadly concerned with the application of Aristotelian principles to space, time, and motion, Chapter 5 with the philosophy of matter, and Chapter 6 with animate nature, evolution, and the human brain.

One strength of the book is actually its negative character, that is, how it relentlessly considers and negates the possibility or plausibility of alternative principles. For first principles cannot be demonstrated, strictly speaking, from principles that are prior to them. They can only be manifested (e.g., using principles prior to us) or defended in some other way (for instance, recall Aristotle’s defense of the principles of non-contradiction in Metaphysics IV). Since the particular sciences or parts of philosophy must assume certain starting points as true, it therefore falls to another type of knowledge to defend those principles (for instance, see Physics, I.2, 185a1–4). This is why metaphysics is “called first philosophy, insofar as all the other sciences come after it by accepting their principles from it” (St. Thomas, SBdT, q. 5, a. 1, c.). In this way, metaphysics is also architectonic, insofar as its provides the theoretical marching orders, so to speak, to the other disciplines. In Aristotle’s Revenge, Feser’s is a brilliant architectonic of retorsion and reductiones ad absurdam that gives no quarter to the metaphysical foes of the Aristotelian philosophy of nature.

Yet this extensive dialectical engagement with metaphysical enemies does not mean that Feser is unable to find any fellow travelers, allies, or friends of the Aristotelian metaphysical project. This is the other characteristic strength of the book. As Aristotle often notes, the human mind is sometimes “forced by the truth itself” towards a certain conclusion (e.g., Metaphysics, I.3, 984a18 and b10). Of course, this often enough turns out to be Aristotle’s conclusion.

So, on the one hand, Feser frequently cites philosophers outside Aristotelian or Thomistic circles to show that arriving at Aristotelian or Thomistic positions requires no special school loyalty (among other examples: support for epistemic structural realism [158–64, 191–93]; reconciling relativity with the A-theory of time [273]; defense of color realism [351]; the defense of holism in biology [384–86]). On the other hand, there are others who philosophized better than they knew and ended up with virtually Aristotelian conclusions or rediscoveries of the Stagirite’s positions, if only their arguments were pressed a bit further, clarified, or seen in a more favorable Aristotelian light (to take a few prominent examples: the embodiedness of cognition [95–97, 97ff]; the neo-Aristotelian approach to understanding laws of motion [177–90]; the reality of motion [at 215]; problems attending denying the reality of temporal passage by making a metaphysics out of mathematical method [261–64]; computationalism and nature [see 369–71]; and arguments about teleology’s relation to natural selection [in particular, 416]).

All of this being the case, present-day Aristotelians and Thomists will find much to agree with and learn from in Feser’s book. There are also various points of detail that deserve further discussion and debate. Thus, the great value of Aristotle’s Revenge should be clear, as well as the worth of furthering its aims or critically engaging with certain of its premises and conclusions. Feser has gathered and ordered a nearly universal range of topics and contemporary sources in the philosophy of nature and science. His order and focus upon the centrality of Aristotelian principles and the arguments in their defense show Feser’s skill as a teacher and philosopher, expounding difficult and foundational subjects. It is a work of “first philosophy” exercising its architectonic role (see Metaphysics, I.2). Feser has shown that the architect in charge of the project of understanding nature still goes by the name “Aristotle.”