Thanks for the long post and the many insightful points and queries.
Since Aristotle is the founder of naturalized ethics, it is really important that we get him right. Aristotle does not base his ethics upon “human nature,” but what he calls “the human function.” (Sorry, I don’t know the Greek) The human function comprises the way of living for which nature has suited humans. That is, just as the Great White Shark is suited (as the Richard Dreyfus character says in Jaws) to swim, eat, and make little sharks—and to do these things very well—so nature has also adapted us to live a certain way and to do it well. What humans are uniquely well-suited to do is to live the life of a rational being in a political society with other rational beings. That is, just like other organisms, nature endows the human creature with potentialities which, when fully actualized, permit that creature to fulfill a particular set of functions in an optimal manner.
There is a crucial difference, however, between the way those potentialities are actualized in humans and the way they are actualized in most other animals. A shark does not have to practice at being a shark (so far as I know). The shark develops its sharky potentials automatically and unreflectively. With humans, however, it takes hard work, discipline, and practice. Learning to be human is a lot like learning to play the piano. The intellectual and moral virtues for Aristotle are the distinctive, habitual practices whereby humans achieve excellence in fulfilling their natural function. Those who practice the moral virtues (i.e., those who are courageous, temperate, just, generous, etc.) are precisely those who will, in general, have the greatest success in living harmoniously and fruitfully with other people.
Aristotle recognized as clearly as anyone else that the vast majority of human beings do not live virtuous lives. If “human nature” is how we spontaneously act, without training and discipline, then “human nature” is often at odds with the fulfillment of the human function. We all too often spontaneously pursue the greedy or myopic ends. A human must learn to be, e.g., courageous or temperate by doing courageous or temperate acts, says Aristotle, just as we learn to play the piano by practicing. The upshot, then, is that the standard for Aristotle is the human function—what nature has suited us to do, not “human nature”—what people in fact tend spontaneously to do. Happiness, eudaimonia, is defined not in terms of what people actually do, but in terms of what they are distinctively suited to do, that is, to live lives of intellectual and moral excellence. Aristotle’s concept of happiness is akin to Maslow’s idea of self-actualization. Those few self-actualized persons (like, say, Socrates) who do live the life for which we are best suited are the ones who are genuinely happy, even when their lives are difficult. Fools, on the other hand, cannot be happy even in the midst of pleasures. Better to be Socrates having a bad day than Sarah Palin having a good one.
It is also very important not to read alien or anachronistic notions into the Aristotelian view of teleology. For Aristotle, teleology is a thoroughly naturalistic concept; indeed, telos is a distinctive feature of physis (nature). There is no sense in which for Aristotle (as opposed to the Christian Aristotelians) that natural ends are intended, planned, or chosen. Indeed, some top Aristotelian scholars like my mentor at Pitt, Jim Lennox (also an expert on Darwin) see no contradiction at all between Aristotelian teleology and Darwinian evolution. Why are sharks so well suited by nature to swim, eat, and make little sharks? Why are they so well adapted to perform these functions and thus achieve their telos to be a top predator? Aristotle could only say that they were so adapted by nature; after Darwin we can explain how it happened.
The upshot is that even a post-Darwinian ethicist can identify natural states that, when achieved, constitute flourishing for the human organism. We can also recognize that humans do not attain that state automatically or by instinct, but only by choice and habituation. Even modern-day naturalists can recognize a standard other than how the majority of humans do act. We can recognize as valuable things other than what the majority do value (John Stuart Mill got confused on this point in Utilitarianism). Thus, the majority may value watching Dancing with the Stars, American Idol, and Survivor (I am appalled to know people with Ph.D.’s who do), yet it is not just snobbery to say that a steady diet of such stuff will make you less happy and well off in the long run. Read a good book, or at least switch over to the Discovery Channel every now and then. A mind is a terrible thing to waste watching meretricious, moronic shit. You really will be happier if you develop your mind instead of lazily letting it deteriorate on a diet of intellectual junk food.
But might we not remake the human function? Indeed, is this not just what Aldous Huxley imagined in Brave New World? By the year A.F. (After Ford) 632, a combination of genetic engineering and operant conditioning has transformed humans into docile, hedonistic, agreeable, conformist, fun-loving creatures who live a life of sex, drugs, and rock and roll and hardly ever cause any problems for the authorities. Even their religion (weekly “solidarity services”) consists of taking drugs and having orgies. All great art and music is, of course, kept strictly hidden, surreptitiously enjoyed only by the World Controllers. Even the alphas, the most intelligent caste of people in BNW, were kept emotionally immature and strongly discouraged from engaging in independent thinking or forming deep emotional attachments (there are no families and total sexual promiscuity is the rule).
Now I was seventeen years old when I first read BNW, and I had a hard time seeing a downside to it. The solidarity services in particular sounded much more interesting than our Sunday services at Alexander Memorial Presbyterian. Now, of course, the way that people live in BNW appalls me, but should it? If, like John the Savage in the novel, I were brought into BNW from outside, would I have any basis for complaint about their way of living? It would horrify me that Shakespeare and Beethoven were unknown. But, hadn’t people been changed so that they could no longer understand or appreciate Shakespeare or Beethoven; great art and music would be confusing or painful for them. People’s capacities had been changed. The human function had been changed. If the human function sets my standard, what right have I to complain or criticize?
Something that John Stuart Mill said that was not confused was that goods differ qualitatively as well as quantitatively. Bentham said “pushpin (bowling) is as good as poetry” if it gives the same amount of pleasure. Mill recognized that poetry might give a kind of pleasure that is so qualitatively different from the form that bowling gives, that it is misleading to try to weigh them in the same quantitative scale. Still, it might be possible to compare them. How? Ask someone who enjoys both bowling and poetry to tell you which one they would sacrifice if they had to give one up. Mill says that the qualitatively superior pleasure is the one genuinely preferred (and not preferred, say, because of an ideological or religious mandate) by one who has had a full experience of both.
At one time in my life I listened to music like Black Sabbath (I did mention that I was once seventeen). I have since listened to Mozart. Having had experience of both, I judge that Mozart is (infinitely) qualitatively superior to Ozzy Osbourne. If you have had experience of the sorts of superficial pleasures of the inhabitants of BNW, and you have also experienced the real depth and meaning, it is not arbitrary to judge that the latter are, objectively, qualitatively superior to the former. The people in BNW are still human and are compelled to lead an emotionally and intellectually stunted life, a life inferior to the one they could have been allowed to live. We can therefore rationally oppose any plans to change human beings so that they are constrained to live in such a stunted state.
What, though, if we discovered a different species, one truly incapable of the sorts of fulfillment and pleasures we find most enriching? Suppose, for instance, we discovered intelligent beings that were naturally adapted to a eusocial lifestyle, like honeybees? Among these eusocial beings, a worker really would experience her greatest fulfillment and well-being in serving the Queen. An ethical naturalist would have to say that many of our values, such as our notions of individualism and autonomy, simply would not and could not be values for such creatures. Would not such beings—entirely reasonably—have a very different set of values and duties? Indeed, the Good for these beings would be different than the Good for humans. For us it is self-fulfillment; for them it is serving the Queen. In short, ethical naturalism seems to imply that values are species-relative. I see no real problems with that.
As for our views of non-human animals on a naturalistic perspective, there is no reason why the well-being of members of other species cannot or should not also be important to us. My cats’ well being is more important to me than the well being of very, very many human beings. Given a choice between saving my cats and saving a lifeboat full of right-wing radio pundits, TV preachers, and Tea Partiers, I’d save the kitties and let the lifeboat of idiots go to the bottom. I would sleep like a baby that night. Indeed, I would argue that an important part of human happiness involves valuing the happiness of at least some kinds of animals.
Note: I will not be posting or commenting on this site for the next couple of weeks. I do appreciate responses, and I will be able to reply when I am communicado again.