Ed Feser wrote a thoughtful response to my earlier post on Scholasticism. And I’d like to expand on his comments, as my afterthoughts on Pieper’s point were brief.

I’m a bit puzzled by John’s statement that “Scholasticism presupposes an Aristotelian philosophy of nature that is simply not adequate to support what modern science has uncovered about the natural order,” since I and other writers whose work John knows and respects (e.g. William Carroll) have argued that there is no conflict between an Aristotelian philosophy of nature and modern science. Indeed, we argue that the latter is best interpreted in light of the former. I’m pretty sure John is familiar with those arguments in at least a general way, so it would be interesting to know exactly what he thinks is wrong with them. Unfortunately, he not only doesn’t tell us, but doesn’t give the reader an indication that the arguments even exist! 

I’m also puzzled by the rhetorical question about how an Aristotelian philosophy of nature might be useful in apologetics, given that I never shut up about how crucial the theory of act and potency is to causal arguments for God’s existence, how crucial immanent teleology or final causality is to Aquinas’s Fifth Way, the role hylemorphism plays in the Third Way, etc.  (I’ve explained all this at length in Aquinas and in various academic articles, and of course here at the blog.)

Beyond directly theological issues, does modern physics have anything to say to metaphysics, and therefore indirectly to theology? Some might argue not, on the grounds that metaphysics speaks about such general features of reality – of being as being – that it cannot be affected by discoveries of particular contingent facts about the world. And yet, Aristotelian metaphysics, which has such an important place in Catholic thought, was not conceived in isolation from scientific investigation. Aristotle was himself a great scientist and both his metaphysics and science make use of the same technical apparatus of form, matter, substance, accident, potency, act, and so on. Indeed, it was largely as a theory of nature that Aristotelianism first commended itself to medieval Christian thinkers.

It is a great problem that traditional Aristotelian/Thomistic metaphysics and modern science no longer speak the same language, as they did in the Middle Ages. Indeed, there are many terms and concepts in the language of each that are now almost untranslatable into the language of the other. Some argue that this is the fault of modern science, which restricted its attention to a limited range of questions having to do with the merely quantitative aspects of things and with efficient and material causes at the expense of formal and final causes. While there is some truth in this, it is only a part of the story. The language of Aristotelian/Thomistic metaphysics has changed very little since the advent of modern science and its vocabulary seems from a scientific perspective quite stilted and awkward for many purposes.

Physics has had enormous success in explaining why things happen as they do in the natural world, but its modes of explanation do not fit neatly into the four-fold classification of material, formal, efficient, and final causes. For example, when physicists explain the electrical conductivity of metals in terms of the “band structure” of the energy levels of the electrons in a crystal lattice of atoms, to which of the four causes does that correspond? As this example illustrates, explanation in modern physics is almost entirely in terms of mathematical structure and involves an enormously rich set of ideas about form. The fact that modern science is nonetheless typically accused by Aristotelian/Thomistic metaphysicians of neglecting “formal cause” shows that they are working with a different notion of form than are contemporary physicists and mathematicians. In Aristotelian/Thomistic philosophy, the ideas of formal causation and substantial form have a teleological thrust that is largely missing from the physicist’s conception of form, which corresponds more to Lonergan’s broader idea of form as “intelligible structure”.

Another example of a linguistic/conceptual difference between Aristotelian thought and modern science is that the former usually envisions the action of one thing upon another (for example fire heating iron), whereas in modern physics the physical world is explained in terms of mutual “interactions”. A third example is that the notions of “species” in Aristotelian philosophy and modern biology are not compatible. Aristotelian species are what mathematicians call “equivalence classes”, so that if A is of the same species as B, and B is of the same species as C, then A must be of the same species as C. However, it does not appear possible in biology to define species in a way that always satisfies this condition. (The existence of “ring species”, such as the Larus gulls, illustrates the problem, as indeed does “speciation” in evolution, whereby all animals are of the same species as their parents and offspring, but not as their remote ancestors or descendents.)

 

In short, Aristotelian/Thomistic philosophy has paid a heavy price for the two and a half centuries in which it largely ignored what was going on in the natural sciences. A sustained re-engagement with science would enrich its conceptual and linguistic resources. This re-engagement cannot simply be an attempt to translate statements of modern science into existing Aristotelian terms. That cannot be done in many cases. Rather, many more Aristotelian/ Thomistic metaphysicians than currently do must learn to listen to and understand science in its own native tongue. Modern physics has made discoveries (e.g. quantum mechanics) which undoubtedly have profound metaphysical implications, but what those implications are cannot be explored unless the physics is understood directly and not “in translation”.