ARISTOTLE TO AUGUSTINE and held their discussions The Lyceum was not a private club like the Academy; many of the lectures given there were open to the general public without fee Aristotle’s anatomical and zoological studies had given a new and deWnitive turn to his philosophy Though he retained a lifelong interest in metaphysics, his mature philosophy constantly interlocks with empirical science, and his thinking takes on a biological cast Most of the works that have come down to us, with the exception of the zoological treatises, probably belong to this second Athenian sojourn There is no certainty about their chronological order, and indeed it is probable that the main treatises—on physics, metaphysics, psychology, ethics, and politics—were constantly rewritten and updated In the form in which they have survived it is possible to detect evidence of diVerent layers of composition, though no consensus has been reached about the identiWcation or dating of these strata In his major works Aristotle’s style is very diVerent from that of Plato or any of his other philosophical predecessors In the period between Homer and Socrates most philosophers wrote in verse, and Plato, writing in the great age of Athenian tragedy and comedy, composed dramatic dialogue Aristotle, an exact contemporary of the greatest Greek orator Demosthenes, preferred to write in prose monologue The prose he wrote is commonly neither lucid nor polished, though he could compose passages of moving eloquence when he chose It may be that the texts we have are the notes from which he lectured; perhaps even, in some cases, notes taken at lectures by students present Everything Aristotle wrote is fertile of ideas and full of energy; every sentence packs a massive intellectual punch But eVort is needed to decode the message of his jagged clauses What has been delivered to us from Aristotle across the centuries is a set of telegrams rather than epistles Aristotle’s works are systematic in a way that Plato’s never were Even in the Laws, which is the closest to a textbook that Plato ever wrote, we Xit from topic to topic, and indeed from discipline to discipline, in a disconcerting manner None of the other major dialogues can be pigeon-holed as relating to a single area of philosophy It is, of course, anachronistic to speak of ‘disciplines’ when discussing Plato: but the anachronism is not great because the notion of a discipline, in the modern academic sense, is made very explicit by Aristotle in his Lyceum period 74