 In Metaphysics Α.1, Aristotle says that “everyone takes what is called ‘wisdom’ (sophia) to be concerned with the primary causes (aitia) and the starting-points (or principles, archai)” (981b28), and it is these causes and principles that he proposes to study in this work. It is his customary practice to begin an inquiry by reviewing the opinions previously held by others, and that is what he does here, as Book Α continues with a history of the thought of his predecessors about causes and principles.