The article distinguishes between psychological egoism and ethical egoism, and explores two questions, based upon some achievements in western ethics and the author's own research: Does psychological egoism correctly describe human nature and psychology? Is ethical egoism a correct normative ethical theory? Through a series of arguments, the author concludes that psychological egoism, as a descriptive theory, does not correctly describe human nature or psychology, and that ethical egoism, as a normative ethical theory, does not hold water even though it has some advantages.