 If people do sometimes have ultimate desires for the well-being of others, and these desires motivate behavior, then altruism is the correct view, and egoism is false. However, if all ultimate desires are self-interested, then egoism is the correct view, and altruism is false. The effort to establish one or the other of these options has given rise to a vast and enormously sophisticated empirical literature. For an overview of that literature, see the  empirical approaches to altruism entry.