an eminent Greek philosopher, born at Miletus; the friend, scholar, and successor of Anaximander. He diffused some degree of light upon the obscurity of his master's system. He made the first principle of things to consist in the air, which he considered as immense or infinite, and to which he ascribed a perpetual motion. He asserted that all things which proceeded from it were definite and circumscribed; and that this air, therefore, was God, since the divine power resided in it and agitated it. Coldness and moisture, heat and motion, rendered it visible, and dressed it in different forms, according to the different degrees of its condensation. All the elements thus proceeded from heat and cold. The earth was, in his opinion, one continued flat surface.

a Greek historian and rhetorician, was born at Lampsacus about 580 years before Christ. Some writers ascribe to him the Treatise on the Principles of Rhetoric, which bears the name of Aristotle; and it is reported that Philip of Macedon invited him to his court to instruct his son Alexander in that science. He attended Alexander in his expedition against Persia. The history of Philip, of Alexander, and likewise twelve books on the early history of Greece, were the productions of his pen, but none of them has been preserved.