GEMISTUS, or PLETHO, Georgius, held high office under the Byzantine emperors during the first half of the 15th century, aud derived his name, which signifies the Replete, from the extraordinary amount of his erudition. He is, however, chiefly memorable for having been the first person who introduced Plato to the Western world. This took place upon his visit to Florence in 1438, as one of the deputies from Constantinople on occasion of the general council. Cardinal Bessarion became his disciple; he produced a great impression upon Cosmo de’ Medici; and though not himself making any very important contribution to the study of Plato, he effectually shook the exclusive domination which Aristotle had exercised over European thought for eight centuries. He promoted the union of the Greek and Latin Churches as far as possible, but his efforts in this direction bore no permanent fruit. He probably died before the capture of Constantinople. The most important of his published works are a treatise on the distinction between Plato and Aristotle as philosophers, and one on the religion of Zoroaster. In addition to these he compiled several volumes of excerpts from ancient authors, and wrote a number of works on geography, music, and other subjects, many of which still exist in MS. in various European libraries.