Abstract
It is now a widespread opinion among interpreters that Aristotle’s History of Animals is not a mere collection of empirical data but has its own theoretical framework; however, there is still disagreement as to exactly what this framework is. To address the problem, the article analyzes in detail the diairetic schemes of HA I 1, attempting to overturn the common opinion that this chapter is a mere expository introduction to the study of animals’ differences. On the contrary, it will be shown that in this chapter Aristotle not only applies the method of ‘multiple division’ theorized in Parts of Animals I 2–4, but also uses dividing criteria that are informed by his causal theory and his hylomorphist ontology. This analysis will therefore lead to the more controversial conclusion that HA is not an ‘early’ work by Aristotle but a mature treatise with its own specific theoretical aim: the aitiological explanation of the anatomical, eco-physiological and ethological differences among animals.