Diocles of Carystus (4th century BCE) was one of the most prominent medical authorities in antiquity. He wrote extensively on a wide range of areas. His views betray a strong philosophical influence, presenting striking connections with the Hippocratic Corpus, Plato, Aristotle and Theophrastus. This book presents all remaining fragments of his views. The Greek, Latin and Arabic sources are faced with their English translations and are followed by a commentary.