The document discusses the concepts of egoism and the two types of egoism: psychological egoism and ethical egoism. Psychological egoism is the view that humans are always motivated by self-interest, even when helping others. Ethical egoism is the normative view that one ought to pursue self-interest above all else. The document also notes that ethical egoism can be further divided into strong and weak versions, with the strong version claiming self-interest should always be the sole motivator of actions.