You care about what others believe about you. What others believe about you determines whether you have a good reputation, whether you have the respect of your peers, and whether your friends genuinely like you. Your caring about others’ beliefs makes sense, because others’ beliefs bear directly upon your level of well-being. Your beliefs can influence others’ well-being, as much as their beliefs can influence yours. How your beliefs influence another’s well-being is a different matter from whether your beliefs are supported by the evidence. Sometimes you can benefit another person by regulating your beliefs in response to considerations of her well-being, not (only) of the evidence. Usually, you do not have strong reasons to regulate your beliefs in response to considerations of the interests of others. But it can be different when the person in question is your friend. Within some perfectly good friendships, the support that each friend provides for the other extends as far as their being willing to regulate their beliefs with the goal of benefiting the other, even if that makes it less likely that their beliefs will be supported by the evidence. Within our friendships, we then have reasons for belief that do not arise directly from, and sometimes compete with, reasons provided by evidence. This claim conflicts with the widespread Aristotelian view that good friendship is oriented to virtue. But it fits with a more plausible view about friendship, on which the function of friendship is to help us cope with the fact that we are not fully virtuous, and to serve needs that we have because we are not fully virtuous.