A comparison of these three periods of Aristotle’s life discloses the uniformity of that life, from beginning to end. He was, from the time he entered the Academy to the founding of the Lyceum, a teacher. Even as pupil of Plato his original mind was influencing the Platonic teaching into new channels. During his second period he was a traveler, to be sure; but he was more,――a collector and a king’s tutor. He was always Aristotle, the philosophical teacher. Hence the periods of his life cannot be so sharply marked as Plato’s, and the lines that are drawn point only to phases of a life that had unity, like his doctrine. His life is a regular development from sources in his first period, and with no later deviating influence. =The Writings of Aristotle.= On every page of Plato’s dialogues you meet Plato; in Aristotle’s writings the personality of the author is subordinated to his science. The collections of writings transmitted under the name of Aristotle do not give even an approximately complete picture of the immense activity of the man. They form, indeed, a stately memorial, even after the spurious writings have been omitted, but their bulk is small compared with what we know was the product of his literary workshop. Forty treatises have been preserved. A catalogue of the library of Alexandria in 220 B. C. includes a list of one hundred and forty-six others, which have since been lost. Aristotle was writer, lecturer, teacher, and the administrator of the Lyceum. His leadership of that school, his careful direction of his coöperators in research and study, was not only an instruction but an impulsion to independent scientific study for all time. His great collections of scientific data can be explained only by their being the combined efforts of many different forces, guided and schooled by a common master. The world was ready to take an account of stock, and Aristotle was the first encyclopædic philosopher. =1. The Popular Writings, published by Aristotle himself.= These were intended for a circle of readers wider than his own school. No one of these works is extant in complete form. They were written by Aristotle during his life in the Academy. They were dialogues in form; in content they were discussions of justice, wealth, wisdom, rhetoric, politics, love, conduct, prayer, generosity, education, government, etc. They were less artistic than Plato’s dialogues, but more original and striking; and they were full of happy inventions and rich thought, expressed in florid diction. The ancients spoke often of Aristotle’s “golden flow of thought,” but this cannot truthfully apply to any save these lost writings.