Michael Constantine Psellus (Greek: Psellos) the younger, born in 1018 (probably at Nicomedia; according to some, at Constantinople) of a consular and patrician family, was a philosopher.

He studied at Athens and Constantinople, where he became intimate with John Xiphilinus. Under Constantine Monomachus (1042-1054) he became one of the most influential men in the Byzantine Empire. As professor of philosophy at the newly founded academy of Constantinople he revived the cult of Plato at a time when Aristotle held the field; this, together with his admiration for the old pagan glories of Hellas, aroused suspicions as to his orthodoxy. At the height of his success as a teacher he was recalled to court, where he became state secretary and vestarch, with the honorary title of "prince of philosophers." Following the example of his friend John Xiphilinus he entered the monastery of Olympus (near Prusa in Bithynia), where he assumed the name of Michael. But, finding the life little to his taste, he resumed his public career. Under Byzantine emperors Isaac I Comnenus and Constantine Ducas he exercised great influence, and was prime minister during the regency of Eudocia Macrembolitissa and the reign of his pupil Michael Parapinaces (1071-1078). It is probable that he died soon after the fall of Parapinaces.

Living during the most melancholy period of Byzantine history, Psellus exhibited the worst faults of his age. He was servile and unscrupulous, weak, fond of intrigue, intolerably vain and ambitious. But as a literary man his intellect was of the highest order. In the extent of his knowledge, in keenness of observation, in variety of style, in his literary output, he has been compared to Voltaire; but it is perhaps as the forerunner of the great Renaissance Platonists that he will be chiefly remembered. His works embraced politics, astronomy, medicine, music, theology, jurisprudence, physics, grammar and history.

Of his works, which are very numerous, many have not yet been printed. Among them are: Chronographica (from 976-1077), which in spite of its bias in favour of the Ducases is a valuable history of his time, chiefly on domestic affairs; three Epitaphioi or funeral orations over the patriarchs Michael Cerularius, Lichudes and Xiphilinus; works against the Bogomils and Euchites; writings on demonology, including a classification of demons. His letters (nearly 500 in number) are also full of details of the period. A complete list of his works is given in Fabricius, Bibliotheca graeca, x. 41. On Psellus himself see Leo Allatius, De Psellis et eorum scriptis (f 634); E Egger in Dictionnaire des sciences philosophiques (1875); A Rambaud in Revue historique (1877); PV Bezobrazov, Michel Psellos (1890; in Russian); C Neumann, Die Weitsiellung des byzantinischen Reiches vor den Kreuzzugen (i 894); Karl Krumbacher, Geschichte der byzantinischen Literatur (1897); JE Sandys, Hist. of Classical Scholarship (1906), i. 411.

This article incorporates text from the public domain 1911 Encyclopædia Britannica.