A philosophical and theological system propounded by Georg Hermes (1775-1831), German Roman Catholic theologian, professor of theology at Münster. He had studied philosophy at Münster and had been deeply influenced by the rationalism and idealism of Kant and Fichte. He tried to establish the truth of Christianity by reason alone. Theology, he argued, must begin with positive doubt. Kant had held that God's existence was a postulate of man's reason in its practical or moral use. Hermes thought God's existence could be demonstrated by theoretical reason, which determines and categorizes the data supplied by sense intuition. Hence the consciousness that “I know” and the thought that “something is there” involve variations that require a sufficient and absolute reason for their origin. From this point Hermes argued for the possibility of divine revelation. The dualism of theoretical reason and practical reason runs throughout his work. The “belief of the reason” is brought about by demonstration. The “belief of the heart” is the accepting of revealed truths by a free surrender of the will. Hermes's principal writings were Einleitung in die christkatholische Theologie (1819-29) and Positive Einleitung (1829). His followers were influential in the universities, but in 1835 Gregory XVI condemned the system, largely for its basic rationalism and tendency to skepticism. There was strong opposition to the decision, but in 1870 it was confirmed by Vatican Council I.*