 According to a doctrine called “psychological egoism”, all human action is ultimately motivated by self-interest. The psychological egoist can agree with the idea, endorsed by common sense, that we often seek to benefit others besides ourselves; but he says that when we do so, that is because we regard helping others as a mere means to our own good. According to the psychological egoist, we do not care about others for their sake. Altruism, in other words, does not exist.