his indifference to "logic-choppers." How little sympathy Aristotle can have had with his pupil’s ambitions is shown by the fact that though his political theories must have been worked out during the very years in which Alexander was revolutionising Hellenism by the foundation of his world-empire, they contain no allusion to so momentous a change in the social order. For all that Aristotle tells us, Alexander might never have existed, and the small city-state might have been the last word of Hellenic political development. Hence it is probable that the selection of Aristotle, who had not yet appeared before the world as an independent thinker, to take part in the education of the Crown Prince was due less to personal reputation than to the connection of his family with the court, taken together with his own position as a pupil of Plato, whose intervention in the public affairs of Sicily had caused the Academy to be regarded as the special home of scientific interest in politics and jurisprudence. It may be true that Alexander found time in the midst of his conquests to supply his old tutor with zoological specimens; it is as certain as such a thing can be that the ideals and characters of the two men were too different to allow of any intimate influence of either on the other. When Alexander was suddenly called to the Macedonian throne by the murder of his father in 336 B.C., Aristotle’s services were no longer needed; he returned to Athens and gave himself to purely scientific work. Just at this juncture the presidency of the Academy was vacant by the death of Speusippus, Aristotle’s old associate in biological research. Possibly Aristotle thought himself injured when the school passed him over and elected Xenocrates of Chalcedon as its new president. At any rate, though he appears never to have wholly severed his connection with the Academy, in 335 he opened a rival institution in the Lyceum, or gymnasium attached to the temple of Apollo Lyceus, to which he was followed by some of the most distinguished members of the Academy. From the fact that his instruction was given in the _peripatos_ or covered portico of the gymnasium the school has derived its name of Peripatetic. For the next twelve years he was occupied in the organisation of the school as an abode for the prosecution of speculation and research in every department of inquiry, and in the composition of numerous courses of lectures on scientific and philosophical questions. The chief difference in general character between the new school and the Academy is that while the scientific interests of the Platonists centred in mathematics, the main contributions of the Lyceum to science lay in the departments of biology and history.