Ronnie de Sousa, professor emeritus of philosophy at the University of Toronto, penned quite a piece of sophistry for Aeon Magazine. The title: “Natural-born existentialists“; the by-line, “Ethics cannot be based on human nature because, as evolutionary biology tells us, there is no such thing.” It’s unfortunate that de Sousa is a professor, and from a fairly prestigious institution, because it gives credence to what I can only call a very small-minded conception of nature.
To be sure, Aristotle and Aquinas worked with a flawed conception of nature inasmuch as they saw the universe to be hierarchically structured by static principles: unchanging celestial spheres which mechanically determined sublunary events, ensuring that species, even if they varied from individual to individual, would stay the same “always or for the most part”. But to identify their concepts of nature with this stability is an error pars pro toto, of taking the part for the whole. Rather, looking for such stability was part of the method of discovering what is natural; which is not the same as what nature itself is, but only a sign of a nature. Furthermore, stability is not the same as stasis, and while there may not be static species, there are definitely stable members (or tokens) constituting an identifiable kind (or type). If this is not the case, all categorization and distinction is fiction.
Anyone really interested in the tougher philosophical nitty-gritty of the issue might be interested in a paper I wrote some years ago on Heidegger’s interpretation of Aristotle’s notion of nature.
The short, sweet, and simple version is this: in order for anything to change, it requires something which is, relative to itself, unchanging; the floor has to remain intact, solid, and relatively inflexible for someone to jump from it (unless it has some sort of spring involved); the axle must remain in the center of the wheel for it to turn; and anything, in order to produce any effect, must remain in existence long enough for that effect to occur. In short, de Sousa’s objection to the existence of natures on the grounds that beings evolve is like saying that because nightfall occurs in 6 hours, the day is already over.