Or so it is claimed. The answer, however, generates problems of its own. To begin with, co-operation is, as such, amoral. We can't tell whether it's good or bad, right or wrong, until we know whether it's being performed by responsible agents and to what ends or purposes. The fact that ants co-operate doesn't tell us anything at all about ethics; and the fact that Nazis co-operate is nothing to celebrate.
Next, it is misleading to conceive of the problem as that of deriving altruism from selfishness. It was Auguste Comte who identified morality with icily disinterested "altruism", thereby rendering all interests selfish. But why take our cue from him? If we should sacrifice ourselves altruistically for the flourishing or well-being or good of other people, then presumably they should sacrifice themselves for ours. But if we have a good that obliges others, then surely it obliges us, too. Comtean altruism is incoherent. Thomas Aquinas makes better ethical sense: since creation is good in God's eyes, and since human beings are creatures, it follows that human beings have a moral duty to care for their own well-being. The pursuit of a morally legitimate interest in the good of self-preservation only becomes immoral — only becomes selfish — when it rides roughshod over other kinds of good, whether one's own or someone else's. Self-interest is not necessarily selfish.
Third, and most important, the tendency of many evolutionary stories about ethics is to assume that material self-interest — the bare preservation of one's life or one's genes — is not only the historical origin, but the continuing basis, of all other human interests. That is, they assume that all human interests are essentially extensions of the one basic and overriding desire for material self-preservation, and are therefore reducible to it. What's wrong with that? Well, for one thing, an altruism that is essentially a shrewder form of self-interestedness isn't really altruism at all.
But a further problem with this materialist assumption is that it's empirically untrue. I defer to the authority of evolutionary biologists, when they tell me that the behaviour of some living beings — and indeed their co-operation — is driven (I shall not say "motivated") by an interest in genetic reproduction. But I demur when they proceed to reduce the behaviour of living human beings to this. Thus J.B.S. Haldane tells me that "I will jump into the river to save two brothers, eight cousins, but not a stranger"; and he attributes this preference for kin to genetic relatedness. I am not persuaded, and I will not be persuaded until it has been shown that the cause of such a choice is the mysterious insistence of genes for reproduction, rather than the immediately felt obligations of gratitude and love.
I have a friend who was adopted at birth. I once made the mistake of referring to his biological father, whom he had never met, as his "real father". Not so. As far as he is concerned, his real father is the one who cared to bring him up. There is no doubt that, faced with the choice of saving either the father to whom he is genetically related or the one who has loved him, my friend would choose the latter. Genes may be monomaniacal, and some beings may be in their thrall; human beings are evidently not. So we need to avoid the genetic fallacy in a double sense: in general, things do not reduce to their genesis — they are more than the sum of their original parts; and in particular, human motivation does not reduce to the blind drive of genes for self-replication.
