In a society of strangers like our own there is I think something especially valuable about this sort of unchosen, unforced contact with others. Besides those benefits we can catalogue the general heading of social capital, there is one other more overtly political gain: the epistemic good that comes from interactions between strangers in a democratic society. An important precondition of any well-functioning democracy, especially, but not only, a deliberative democracy, is that citizens are able to make informed judgements about alternative policies. My claim is that one way we gain the kind of civic knowledge democracy requires is through interaction with people quite different than ourselves. Suppose a person is being asked to vote in a referendum on abortion. If he has talked with women who have had abortions and those who have chosen to keep their children, then he is more likely to be able to make an informed, unprejudiced choice on how to vote. The argument for deliberative democracy turns (in part) on being able to improve the quality of public deliberation; I am suggesting that helping create social institutions where altruism flowers is one way to do this. In a society of relative strangers like our own people tend to be strongly attached to their individual freedom, and at the same time lament the lack of widespread altruism. I have tried to show how encouraging the latter need not threaten the former. True altruism is a choice made from the heart. We can be coerced into simulating it, but to be properly maintained, altruism requires an internal motive. Encouraging altruism often requires indirect strategies which may not always succeed. However, since the good society should be altruistic as well as just and free, there are very good reasons to try.