In this chapter I introduce the thesis that Aristotle’s biology was considerably influenced by medical tradition as represented by the so-called Hippocratic writings. I start with a brief discussion of the history of the debate and the state of investigation and introduce the main advocates as well as opponents of the thesis. I then focus on Aristotle’s remarks on distinguished physicians and the relationship between medicine and natural philosophy in Parva Naturalia. With the help of selected passages from the Hippocratic On Regimen, On Flesh and On Ancient Medicine I make the case that Aristotle reflects upon a specific medical debate on the first principles of human (and animal) physiology and clarifies his own position in it, namely that he takes sides with those physicians who practice their discipline “in a more philosophical manner” and who employ heat, cold, and other such qualities as the starting points of their physiological explanations.

The author of De mundo offers his outline of geography in the second part of Chapter 3. In this contribution, we look at the details of the author’s account and analyse it in the context of the historical development of ancient geographic ideas. There is a number of indications that the text can be dated to later Hellenistic times: the author’s view on the insularity of the inhabited world, on the nature and role of the ocean and its connection with the Caspian/Hyrcanian Sea, on the borders between the continents and on the calculation of the dimensions of the inhabited world (oikoumenē). We argue that the author might have been influenced by the treatises on the ocean as a literary model for this section of De mundo. We know that authors such as Pytheas of Massalia, Posidonius of Apamea and Athenodorus of Tharsus wrote works under the title On the Ocean, which survive only in scarce fragments. The information we can extract from De mundo in this respect is, therefore, invaluable for a reconstruction of the content, circulation and reception of this sub-genre of geographic literature in the last decades of Hellenism.

This chapter concerns the medical background of Aristotle’s accounts of heat, pneuma, and the vegetative soul. Bartoš discusses four Hippocratic texts (namely On Flesh, On Regimen, On Sevens, and On Winds) in which heat/fire plays a prominent role. He illustrates the relation of the notion to soul and pneuma in these texts and suggests several remarkable details of special importance to Aristotle’s zoology.