The period from Plato's birth to Aristotle's death (427-322 BC) is one of the most influential and formative in the history of Western philosophy. The developments of logic, metaphysics, epistemology, ethics and science in this period have been investigated, controversies have arisen and many new theories have been produced. But this is the first book to give detailed scholarly attention to the development of dialectic during this decisive period. It includes chapters on topics such as: dialectic as interpersonal debate between a questioner and a respondent; dialectic and the dialogue form; dialectical methodology; the dialectical context of certain forms of arguments; the role of the respondent in guaranteeing good argument; dialectic and presentation of knowledge; the interrelations between written dialogues and spoken dialectic; and definition, induction and refutation from Plato to Aristotle. The book contributes to the history of philosophy and also to the contemporary debate about what philosophy is.