Socrates’ greatest philosophical contribution was to have initiated the search for definitions. In Definition in Greek Philosophy his views on definition are examined, together with those of his successors, including Plato, Aristotle, the Stoics, Galen, the Sceptics and Plotinus. Although definition was a major pre-occupation for many Greek philosophers, it has rarely been treated as a separate topic in its own right in recent years. This volume, which contains fourteen newessays by leading scholars, aims to reawaken interest in a number of central and relatively unexplored issues concerning definition. These issues are briefly set out in the Introduction, which also seeks to point out scholarly and philosophical questions which merit further study.