Aristotle’s Metaphysics Λ 1. The Inquiry into the Principles of Substances and the Problem of the Unity of Science

In the debate about the object of book Lambda of Aristotle’s Metaphysics, the first chapter, which contains a sort of program for the whole treatise, plays an important role. According to the Aristotelian commentary tradition, in Lambda Aristotle is primarily concerned with the immovable substance, while the section containing the discussion of the sensible substance is an introduction to the actual topic. Some of the most recent interpretations attribute to Lambda the development of a unique science, physics. The paper contains an analysis of Lambda 1, with the aim of showing that its final passage is prepared by what precedes in the text. The interpretation of the final passage of the chapter, in which Aristotle poses the question of the unity of the science of substances, argues for the assignment of the study of sensible substances and unmovable substances to physics and first philosophy respectively.