Rabbi Sir Jonathan Sacks, Chief Rabbi of the British Commonwealth, has an interesting essay in Timesonline on a strong Darwinian argument for religion. Darwin noticed that all cultures value altruism; people generally hold those who make sacrifices for others in high regard. However, in strictly Darwinian terms, if evolution is nothing but a struggle to survive, then ruthlessness should prevail across the board. How to explain this paradox?

In The Descent of Man Darwin hypothesized that cultures with many altruistic individuals would have a selective advantage over societies in which everyone was looking out for Number One. However, for Darwin the precise mechanism for accomplishing this was "at present much too difficult to be solved".

But, as Rabbi Sacks states:

...that of course is precisely the function of religion. God is the voice of the other within the self. It is God who taught us to love our neighbors as ourselves, to welcome the stranger, care for the poor, the widow, the orphan, heed the unheeded, feed the hungry, give shelter to the homeless, and temper justice with compassion. Nietzsche, Darwin's younger contemporary, saw most clearly how unnatural these things are. Nature is the will to power. Faith, in the Judeo-Christian tradition, is care for the powerless.

Without fully realizing what he had done, Darwin was pointing us to the central drama of civilization. Biological evolution favors individuals, but cultural evolution favors groups. So, as Judaism and Christianity both knew, there is a war within each of us as to which will prevail: self-regard or concern for others, egoism or altruism. Selfishness is advantageous to individuals, but disastrous to groups, and it is only as members of a group that we can survive at all. As Darwin himself put it, "Selfish and contentious people will not cohere, and without coherence nothing can be effected".