Aristotle's Nicomachean Ethics is perhaps one of the most influential treatise on moral philosophy. It is a central text in Greek ethics, a primary source of medieval ethics, and a stimulus to thought about morality. Questions discussed include: human happiness and welfare; the nature of a good person; the psychology of action and character; the virtues of character and intellect; praise, blame, and moral resposibility; practical reason; weakness of will; self-interest and the interests of others; the role of friendship in the good life; and the relation between pleasure and goodness.