Chris Taylor

This essay explores the treatment of the relation between nature (phusis) and norm or convention (nomos) in Democritus and in certain Platonic dialogues. In his physical theory Democritus draws a sharp contrast between the real nature of things and their representation via human conventions, but in his political and ethical theory he maintains that moral conventions are grounded in the reality of human nature. Plato builds on that insight in the account of the nature of morality in the myth in the Protagoras. That provides material for a defense of morality against the attacks by Callicles in the Gorgias and Thrasymachus and Glaucon in the Republic, all of whom seek to use the nature-convention contrast to devalue morality.

Almost uniquely for someone whose thought has been so influential, Socrates wrote nothing himself, and our knowledge of his philosophical opinions and method is derived mainly from the engaging and infuriating figure who appears in Plato's dialogues. The philosophy of Socrates and Plato is therefore closely interconnected, and the most powerful elements of Plato's mature thought form the basis of an interpretation of knowledge, reality, and morality which is still held and debated by philosophers today. Aristotle's approach to these and other issues is in many ways directly opposed to that of Plato, and has been no less influential.