 There are two quite different questions we need to ask about how these ideas about inquiry and explanation in the Analytics are related to Aristotle’s investigations of animals: first, how is the philosophy of biology presented in PA I related to the general account of explanation, definition and inquiry in the Posterior  Analytics[4];  and second, to what extent do the treatises reporting his actual investigations of animals conform either to his general account of scientific knowledge and inquiry in APo., or to the norms regarding the study of animals laid down in PA I. The remainder of this entry will be organized around these two questions.