I want to a link to another terrific blog post by philosopher Larry Arnhart.
One worry–perhaps the worry–about basing morality on the biology of human nature is that it makes morality species-specific. Darwin himself voiced this concern in The Descent of Man:
“In the same manner as various animals have some sense of beauty, though they admire widely different objects, so they might have a sense of right and wrong, though led by it to follow widely different lines of conduct. If, for instance, to take an extreme case, men were reared under precisely the same conditions as hive-bees, there can hardly be a doubt that our unmarried females would, like the worker-bees, think it a sacred duty to kill their brothers, and mothers would strive to kill their fertile daughters; and no one would think of interfering. Nevertheless, the bee, or any other social animal, would gain in our supposed case, as it appears to me, some feeling of right or wrong, or a conscience” (Penguin Classics, 2004, pp. 122-23).
As I have said, this argument from people like Cobbe, West, and Forde assumes a Platonic expectation of a moral cosmology–that morality is somehow woven into the fabric of the cosmos as a dictate of a cosmic God, a cosmic Reason, or a cosmic Nature.
I reject this Platonic moral cosmology, because I see no reason why morality cannot rightly be understood as grounded in our evolved human nature, so that what is moral for us would not necessarily be moral for any other species that might develop a moral sense.
Contrary to Cobbe, West, and Forde, I see nothing nihilistic in admiring the bee police for their evolved system of law enforcement, and in seeing this as showing that Friedrich Nietzsche was right to view “the entire phenomenon of morality as animal.”