That the more tender and poetic aspects of Pythagorean speculations had deeply impressed Socrates can be seen by the fact that they recurred to his mind in the most solemn hour of his life. From these he drew the lovely parable with which he gently reproved the friends who were come to take leave of him for their surprise at finding him no wise depressed. He asks if he appears to them inferior in divination to the swans, who, when they perceive that they must die, though given to song before, then sing the most of all, delighted at the prospect of their departure to the deity whose ministers they are. Mankind has said falsely of the swans that they sing through dread of death and from grief. Those who say this do not reflect that no bird sings when it is hungry or cold or afflicted with any other pain, not even the nightingale or swallow or hoopoe, which are said to sing a dirge-like strain, “but neither do they appear to me to sing for grief nor do the swans, but as pertaining to Apollo they are skilled in the divining art, and having a foreknowledge of the bliss in Hades, they express their joy in song on that day rather than at any previous time. But I believe myself to be a fellow-servant of the swans and consecrated to the same divinity, and that I am no less gifted by my master in the art of divination, nor am I departing with less good grace than they.” Socrates would not have been “the wisest of men” if he had dogmatised about the unknowable; to insist, he says, that things were just as he described them, would not become an intelligent being; he only claimed an approximate approach to the truth. In appearance Plato went nearer to dogmatic acceptance of the theory of the transmigration of souls, but probably it was in appearance only. Like his master, he thought it reasonable to suppose that the human soul ascended if it had done well, and descended if it had done ill, and of this ascent and descent he took as symbol its attirement in higher or lower corporeal forms till, freed from the corruptible, it joined the incorruptible. The Greeks were the first people to have an insatiable thirst for exact knowledge; they showed themselves true precursors of the modern world by their researches into scientific zoology, which were carried on with zeal long before Aristotle took the subject in hand. We cannot judge of these early researches because they are nearly all lost; but Aristotle’s “History of Animals,” even after the revival of learning, was still consulted as a text-book, and perhaps nothing that he wrote contributed more to win for him the fame of “... maestro di color che sanno.”