MENCKE (Lewis Otto), in Latin Menckenius, a learned professor of morality at Leipzig, was born at Oldenburg in Westphalia in 1644. He studied in several universities of Germany; and became an able philosopher, civilian, and divine. He was made professor of morality at Leipzig in 1668; and enjoyed that post to his death. He was five times rector of the university of that city, and seven times dean of the faculty of philosophy. He published several works; but his most considerable, and what alone is sufficient to perpetuate his memory, is the Acta Eruditorum of Leipzig, of which he was the first author, and in which he was engaged till his death. The first volume was published at Leipzig, in 4to, in 1682.