[Sidenote: Scientific training and undertakings of Alexander.] [Sidenote: His unbridled passions and iniquities.] If the letter quoted by Plutarch as having been written by Alexander to Aristotle be authentic, it not only shows how thoroughly the pupil had been indoctrinated into the wisdom of the master, but warns us how liable we are to be led astray in the exposition we are presently to give of the Aristotelian philosophy. There was then, as unfortunately there has been too often since, a private as well as a public doctrine. Alexander upbraids the philosopher for his indiscretion in revealing things that it was understood should be concealed. Aristotle defends himself by asserting that the desired concealment had not been broken. By many other incidents of a trifling kind the attachment of the conqueror to philosophy is indicated; thus Harpalus and Nearchus, the companions of his youth, were the agents employed in some of his scientific undertakings, the latter being engaged in sea explorations, doubtless having in the main a political object, yet full of interest to science. Had Alexander lived, Nearchus was to have repeated the circumnavigation of Africa. Harpalus, while governor of Babylon, was occupied in the attempt to exchange the vegetation of Europe and Asia; he intertransplanted the productions of Persia and Greece, succeeding, as is related, in his object of making all European plants that he tried, except the ivy, grow in Mesopotamia. The journey to the Caspian Sea, the expedition into the African deserts, indicate Alexander's personal taste for natural knowledge; nor is it without significance that, while on his death-bed, and, indeed, within a few days of his decease, he found consolation and amusement in having Nearchus by his side relating the story of his voyages. Nothing shows more strikingly how correct was his military perception than the intention he avowed of equipping a thousand ships for the conquest of Carthage, and thus securing his supremacy in the Mediterranean. Notwithstanding all this, there were many points of his character, and many events of his life, worthy of the condemnation with which they have been visited; the drunken burning of Persepolis, the prisoners he slaughtered in honour of Hephæstion, the hanging of Callisthenes, were the results of intemperance and unbridled passion. Even so steady a mind as his was incapable of withstanding the influence of such enormous treasures as those he seized at Susa; the plunder of the Persian empire; the inconceivable luxury of Asiatic life; the uncontrolled power to which he attained. But he was not so imbecile as to believe himself the descendant of Jupiter Ammon; that was only an artifice he permitted for the sake of influencing those around him. We must not forget that he lived in an age when men looked for immaculate conceptions and celestial descents. These Asiatic ideas had made their way into Europe. The