Foht suggests that I am promoting a Darwinian historicism that denies the eternity of human nature as an unchanging essence. He writes:
What bugs me about Arnhart's "Darwinian" philosophy is that it doesn't seem to come to grips with what is really unique in the Darwinian mode of explanation. He talks about this grab-bag list of twenty "natural" desires, and how we ought to use an empirically based understanding of nature as the standard for politics. That's all well and good, but why do you need Darwin to find these twenty natural desires? Ordinary social science (or for that matter, common sense) could tell you that human beings like to have families or practical arts or what-have-you. What makes Darwinian explanation special compared to old-fashioned empirical naturalism is that it stands nature on its head. According to an old-fashioned understanding of nature, nature is the force that makes us who we are, i.e. our essence. For Darwin, however, nature is itself made by an historical process of competition and selection. Our nature is no longer an essence; it is just another historical accident. So I'm not sure how much Darwinism really helps us argue against techno-liberationist policies like transhumanism. If we happen to dislike some aspect of our nature, and we happen to have the technical means to change it, why should it be evolutionary biology that gives us pause?
The real problem for a post-Darwinian political philosophy (conservative or otherwise) is not how to replace "metaphysical" values with "natural" values, but how to reconcile the project of "natural" morality with the historicism of Darwin's nature.
On the first point, I agree that recognizing the twenty natural desires is a matter of common-sense experience that does not require Darwinian science. The value of Darwinian science here is in providing scientific confirmation for this common-sense knowledge by showing the ultimate natural causes for these natural desires in the evolutionary history of the human species.
But that appeal to the evolutionary history of the human species leads to Foht's second point--his worry about Darwinian historicism.
Foht invokes "an old-fashioned understanding of nature" in which "nature is the force that makes us who we are, i.e. our essence," and he contrasts this to "the historicism of Darwin's nature." I assume that Foht is referring here to some kind of Platonic metaphysics of the Theory of Ideas in which human nature is an eternally unchanging Idea or Essence. Alternatively, Foht could be a Christian Platonist who sees God as the Creator of human nature as an everlasting essence.
As I have indicated in many previous posts, I regard Platonic metaphysics as implausible. In fact, it is so implausible that it is not even clear that Plato or Plato's Socrates ever clearly endorses it. (Here I am using some language from some previous posts.)
If Darwin's evolutionary science is correct, then all the species of life come into being and pass away. Species are not eternal or everlasting, but they are real for as long as they last. When Louis Agassiz wrote a critical assessment of Darwin's theory, Darwin wrote to Asa Gray, in a letter of August 11, 1860, that he was "surprised that Agassiz did not succeed in writing something better. How absurd that logical quibble: 'if species do not exist, how can they vary?' As if anyone doubted their temporary existence."
To affirm the "temporary existence" of species denies the Platonic/Socratic teaching that Being--what is really real and fully intelligible--must be eternal and unchanging, as distinguished from the temporal and ever-changing flux of the sensible world.
But as long as we adhere to this Parmenidean assumption that Being is eternally unchanging, we cannot bridge the gap between the unchanging ideas and changing sense experience. This absolute separation of unchanging intelligibles and changing sensibles cannot explain human knowledge, because human cognition is in motion. The intelligibility of being seems to require that it somehow be both in motion and at rest. But, still, we can understand the world by sorting things into classes according to the ways they are like or unlike one another.
We need to go beyond the Parmenidean and Platonic search for invariants and see that reality is a mixture of fixity and flux. We need to see that the history of the cosmos shows an evolutionary emergence of variance and novelty. We can sort things out according to their enduring patterns of similarity and difference. But these enduring patterns are not eternal or everlasting.
This is certainly true for our study of human nature. The human species is not absolutely invariant or eternal. Human beings did not exist before the evolutionary emergence of Homo sapiens, and we can expect that some day the human species will go extinct. But for as long as our species exists, there will be natural propensities and traits that characterize us--including the twenty natural desires.
And yet the present reality of the human species is not invariant, because each human being is unique in being a product of a unique natural history. Biological history depends upon the variation that comes from genetic mutation and from sexual mating, in which the random assortment of genes results in the production of unique individuals. So while we can identify the human species as a range of traits or propensities, we know that within that range, there is immense variation expressed in individual diversity. Human nature as we know it is neither absolutely fixed nor absolutely chaotic.
Without realizing it, Catherine Zuckert--in her Straussian interpretation of Plato--implicitly endorses this Darwinian understanding of the human species in her criticisms of Timaeus's cosmological explanation of the human species. As she indicates, Timaeus cannot account for the unpredictable variation in human beings that comes from human mating and reproduction, because he has to assume that the divine craftsman created human nature as absolutely unchanging. Consequently, Timaeus has to assume that all human beings are born absolutely the same in their natural abilities and traits, which denies the reality of natural individual differences. Thus, as Zuckert indicates, Timaeus's cosmology--in its search for eternal invariance--must deny the obvious facts of sexual reproduction and individual identity.
Some Straussian scholars try to avoid these problems associated with the Platonic Theory of the Ideas. They do that by claiming that this teaching is only a "noble lie" for Plato to satisfy the popular need for a cosmologically supported morality. But the Straussians also want to say that the Platonic teaching about the supremacy of the philosophic life is simply true, and they never explain how this can be sustained without a Platonic cosmology in which Mind rules over all, and philosophy somehow participates in the cosmological intelligibility of the eternal Mind.
My conclusion from all this is that Platonic conceptions of cosmic teleology and the eternity of species are implausible, because they contradict what we know by experience. More plausible, I suggest, is the Darwinian conceptions of immanent teleology and the evolution of species.
But what, then, should we say about Foht's third point--his worry about a transhumanist use of biotechnology to change human nature? First of all, I don't understand why this is a worry for him if he really believes that human nature is eternal and unchanging. If he really believes this, then he should believe that a tranhumanist transformation in human nature is impossible.
As I have indicated in some previous posts, my Darwinian response to transhumanist biotechnology is to argue that the technology for enhancing human powers will be limited both in its technical means and in its moral ends. It will be limited in its technical means, because complex behavioral traits arise from the intricate interplay of many genes interacting with developmental contingencies and unique life histories to form brains that constantly change as they respond flexibly to changing circumstances. Consequently, precise technological manipulation of human nature to enhance desirable traits while avoiding undesirable side effects will be difficult if not impossible.
The technology of human enhancement will also be limited in its moral ends. Human beings act to satisfy their natural desires. The use of technology to enhance human life will be driven by these natural desires. Transhumanists implicitly assume the enduring power of these desires--for example, the natural desire of parents to promote the happiness of their children. But if that is the case, then it is hard to see how human nature is going to be abolished if the natural desires endure.
Related posts can be found here, here, here, and here.
Peter Lawler has written an interesting response to this post.