made a selection from the tenets of all the existing sects. As he himself states in his Elements of Philosophy, he takes as criteria of truth (1) that by which the judgement is formed, namely, the ruling principle of the soul; (2) the instrument used, for instance the most accurate perception. His universal principles are matter and the efficient cause, quality, and place; for that out of which and that by which a thing is made, as well as the quality with which and the place in which it is made, are principles. The end to which he refers all actions is life made perfect in all virtue, natural advantages of body and environment being indispensable to its attainment. It remains to speak of the philosophers themselves, and in the first place of Thales. Cuapter 1. THALES (florwit circa 585 B.c., the date of the eclipse) Herodotus, Duris, and Democritus are agreed that Thales was the son of Examyas and Cleobulina, and belonged to the Thelidae * who are Phoenicians, and among the noblest of the descendants of Cadmus and Agenor. As Plato testifies, he was one of the Seven Sages. He was the first to receive the name of Sage, in the archonship of Damasias? at Athens, when the term was applied to all the Seven Sages, as Demetrius of Phalerum mentions in his List of Archons. He was admitted to citizenship at Miletus when he came to that town along with Nileos, who had been expelled from Phoenicia. Most writers, however, represent him as a genuine Milesian and of a distinguished family.