Part of it started with his politically and philosophically liberal views concerning the equality of all human beings, and the logical consequences of such equality: if we're all equal, then slavery, and the exploitation of blacks and other foreigners must be wrong.
Darwin, as well as some of the ways in which this description of the living world has taken on a life of its own, with implications that go far beyond the world of science, revolutionizing the way we think about ourselves, challenging the need for a creator, undermining dogma, tradition and authority, and making us question the origin and nature of human morality.
Happy birthday, Chuck!
He's an enthusiastic fellow, isn't he? :)
And yes, I may have failed to mention there would be some remarks about thinkers as wide-ranging as Marx, Nietzsche, Malthus, J.B.S. Haldane, William Hamilton and George Price, but now you know :)