Pythagoras and Heraclitus developed theories of the universe and mankind’s place in it which were taken seriously by all later Greek thinkers. None of their works remains, however, except in later paraphrases that all too often are misrepresentations. Pythagoras had followers who attributed their own ideas to their master; Heraclitus wrote in a prose style so ambiguous that he came to be known as the Shadow, so that even the most earnest attempts to paraphrase his views had to smooth out his intentional rough edges. Nonetheless, enough remains to allow the authors of this volume, edited by David Sider and Dirk Obbink (Oxford), to offer new ways of viewing their views and the way others perceived them. The contributors are Gábor Betegh (Budapest), Roman Dilcher (Heidelberg), Aryeh Finkelberg (Tel Aviv), Daniel Graham (Brigham Young University), Herbert Granger (Wayne State University), Carl Huffman (DePauw), Enrique Hülsz Piccone (Mexico City), Anthony Long (Berkeley), Richard McKirahan (Pomona), Catherine Rowett (East Anglia), David Sider (New York), and Leonid Zhmud (St. Petersberg).