Robbie George got what can only be called a source-greaser puff-piece from David Kirkpatrick in the NYT Magazine last weekend. He must have been delighted. For those of you somewhat befuddled by George's argument about natural law, it behooves me to direct you to Chapter 3 of The Conservative Soul where I argue, point by point, against its absolutism and indifference to the actual facts of nature. Among those facts: human reproduction requires the deaths of countless human beings if you count fertilized embryos as fully human; death itself has no absolute clear line in science the harder you look for it; conception itself is very difficult to demarcate exactly at a moment in time; non-procreative sexual acts are endemic in nature and human nature, just as homosexual orientation is ubiquitous; and on and on. For an excellent account of how science, especially neuroscience has also exploded George's Aristotle-Hume axis, see John Culhane here.
But my deeper point is actually an agreement of sorts: there does seem something intuitively right about seeing our "nature" as some sort of guide to the way we should live our lives. But this is the beginning of an argument, not an end to it. What do we mean by nature? How do emotion and reason interact? How precise and universal can we be in adducing morals from something as diverse and varied as the fruits of natural selection? How can we be sure we aren't smuggling in all sorts of pre-existing views of what nature is and what morality is when we declare something "unnatural"? How does an argument that designates an entire sub-section of humankind as inherently immoral square with the goodness of God's creation or the morally neutral power of Darwin's theory?