 First some preliminary remarks are in order about what we are—and are not—discussing. It seems obvious, once stated, that the actual activity of studying animals is different from the activity of writing or teaching about animals based on that study. We have access to a number of Aristotle’s systematically organized writings on animals; we do not have direct access to his actual investigations. Some authors studied by historians of science discuss, in their written work, the methods they used to gather the information and work out their theoretical ideas and even provide ‘diaries’ describing their day-to-day studies—Aristotle is not one of them. Nor did anyone else report observing Aristotle carrying out his studies. There are reasonable inferences we can make from his writings; for example that he consulted with bee-keepers, fishermen and sponge divers, that he (or someone under his guidance) performed a great many dissections on a wide variety of animals, that there were at least some diagrams produced based on these dissections, and so on. Moreover, on the question of how he reasoned to specific explanations we can make some reasonable inferences from things he says about proper methods of biological inquiry. But it is important to keep in mind that we are studying texts that present, in a highly structured and theoretical manner, the results of an actual investigation, the details of which we know very little.