Simplicius, a philosopher of the 6th century, was a native of Cilicia, a disciple of Ammonius the Peripatetic, and endeavored to unite the Platonic and Stoic doctrines with the Peripatetic. Distrusting his situation under the emperor Justinian, he went to Chosroes, king of Persia, but returned to Athens after it had been stipulated in a truce between the Persiains, and the Romans, A.D. 549, that he and his friends should live quietly and securely upon what was their own, and not be compelled by the Christians to depart from the religion of their ancestors. Simplicius wrote commentaries on Aristotle's Categorioe, Physica, De Coelo, and De Anima, which are the most valuable of all the extant Greek commentaries on Aristotle. They are printed in some of the early editions of Aristotle; and are also contained in Scholia. in Aristotelem, collegit Ch. A. Brandis (Berl. 1836). Simplicius also wrote a Commentary on the Enchiridion of Epictetus, which for its pure and noble principles of morality has commanded general admiration. The best separate edition of this commentary is that by Schweighauser, with a Latin translation, in two volumes (Leips. 1800); it has been translated into English by Dr. G. Stanhope (Lond. 1704, 8vo); into French by Dacier (Paris, 1715); and into German by Schulthess (Zurich, 1778).