...the Enlightenment effectively tore out the foundations from under the polite bourgeois morality that it wished to maintain. You cannot do this, says Nietzsche. You have unchained the earth from the sun, a move of incalculable significance. By doing so, you have taken away any basis for a metaphysics that might ground either knowledge or ethics.... The cheerful and chipper atheism of a Richard Dawkins or a Daniel Dennett is not for Nietzsche because it fails to see the radical consequences of its rejection of God. To hope that, say evolution will make us moral would be to assume a meaning and order to nature that can only really be justified on a prior metaphysical basis that itself transcends nature, or simply to declare by fiat and with no objective justification that certain things we like or of which we approve are intrinsically good.
--Carl Trueman, The Rise and Triumph of the Modern Self
I haven't finished this book yet, and will probably have more to say about it. But it's actually better than I expected--not that I didn't expect it to be good, but it's both wider and deeper than I thought it would be.