Here is a short synthesis and comment of the Aristotelian text included in the first book of Metaphysics, Metaphysics, A. In this first book, Aristotle is reviewing the philosophical positions of the thinkers who preceded and accompanied him during the development of the first phase of Ancient Greek Philosophy (archaic and classical). From the first Pre-socratics – Thales, Anaximander, Anaximenes - to Plato and the Academic disciples.