  One issue concerns how much ethical egoism differs in content from standard moral theories. It might appear that it differs a great deal. After all, moral theories such as Kantianism, utilitarianism, and common-sense morality require that an agent give weight to the interests of others. They sometimes require uncompensated sacrifices, particularly when the loss to the agent is small and the gain to others is large. (Say the cost to me of saving a drowning person is getting my shirtsleeve wet.) Ethical egoists can reply, however, that egoism generates many of the same duties to others. The argument runs as follows. Each person needs the cooperation of others to obtain goods such as defense or friendship. If I act as if I give no weight to others, others will not cooperate with me. If, say, I break my promises whenever it is in my direct self-interest to do so, others will not accept my promises, and may even attack me. I do best, then, by acting as if others have weight (provided they act as if I have weight in return).