 The range of Presocratic thought shows that the first philosophers were not merely physicists (although they were certainly that). Their interests extended to religious and ethical thought, the nature of perception and understanding, mathematics, meteorology, the nature of explanation, and the roles of matter, form, causal mechanisms, and structure in the world. Almost all the Presocratics seemed to have something to say about embryology, and fragments of Diogenes and Empedocles show a keen interest in the structures of the body; the overlap between ancient philosophy and ancient medicine is of growing interest to scholars of early Greek thought (Longrigg 1963, van der Eijk 2008). Recent discoveries, such as the Derveni Papyrus, show that interest in and knowledge of the early philosophers was not necessarily limited to a small audience of rationalistic intellectuals. They passed on many of what later became the basic concerns of philosophy to Plato and Aristotle, and ultimately to the whole tradition of Western philosophical thought.