Prioritize Through Purpose (opens in new tab)

I understand the perspective and the rationale is certainly sound on a long timeline (millions of years), but on the timeline of known human history and civilization "human nature" can be observed and defined much more easily.

Even reading the Old Testament and other very old books that give us a picture into a range of a few thousand years, it becomes clear that human nature has not changed in at least that time period. Because of that, observing human nature within the range of a few millennia is perfectly reasonable.

If evolution turns us into something else, then Human 2.0 Nature will become a thing.

The first thing to note is that evolution does not necessary contradict telos. The metaphysical position called evolutionism does by definition, but evolution as biological subject matter does not.

Second, the question about the stability or reality of human nature is separate from the question of telos. Even if we suppose that there is no such thing as human nature, we would still need to admit kinds, each with some telos, but more importantly, the very notion of efficient causality already presupposes telos. Without telos, you cannot explain the regularity of the effects of efficient causes. The effects of efficient causes are not arbitrary, or else science would be impossible. And biology, per my observations, is showing signs of slowly moving toward open acknowledgement of telos. The notion of "function" is teleological, after all!

Third, it is odd to speak of human nature changing. For if there is such a thing, then it is predicable, and predicates do not change. You seem to be making a nominalist sort of claim, i.e., the collection of beings, over time, that we have, for whatever reason, classified as "human" do not actually share the same nature. I cannot make heads or tails of nominalism, nobody can, because I cannot determine why the label "human" was used in the first place and why a mislabeling should be regarded as something significant, as something more than a mislabeling. Nominalism renders the word unintelligible. You might say "Oh, well, we have adaptation!", and I would agree, that human beings have adapted and continue to adapt, but the nature of a thing concerns what is essential or substantial about something. Everything else is either a proper consequence of that (speech), or an accidental adaptation or variation (eye color). As a metaphysician would say, intelligent beings on other planets are, ontologically speaking, also human by virtue of their intellects, even if phylogenetically there is a difference. So, the nominalist claim doesn't even rise to the level of being wrong. I claim that there were humans thousands of years ago, and there are human beings today, and because both instantiate the same human nature.

In any case, Etienne Gilson has written a book[0] on this subject. I wouldn't call it a magisterial or exhaustive philosophical work on the subject (others have produced better [1] if you want more heft), but as an introduction to some basic ideas, IIRC, it isn't bad.

[0] https://a.co/d/iugLuek

[1] https://a.co/d/eGMDJ61