TRITHEISM. — From the Greek τρεῖς = “three” and Θεός = “God”; a tendency among certain theologians who, in their explanation of the mystery of the Trinity, come to admit in God not only three distinct persons but also different natures.
T. appears for the first time, apparently, in the 6th century in the East, in the theological John Philoponus (v.), who, in order to defend Monophysitism, identified the terms “person” and “nature” and therefore, since there are in God three really distinct persons, came to admit three natures as well. Nevertheless, he always energetically refused to speak of three divinities (cf. Timothy, De recept. haeret.; PG 86, 60).
T. is found again in its consequences, if not in its true form, in the nominalist Roscellinus (v.) and in the extreme realist Gilbert Porretanus (v.). For the nominalists, only individual and concrete substances exist, not common and abstract entities. This conception led Roscellinus to the same conclusions as Philoponus. Roscellinus’s T., opposed with compelling logic by St. Anselm and Abelard, was condemned at the Council of Soissons (1092). For the extreme realists, on the other hand, the universal exists in itself. Consistently with this principle, Gilbert Porretanus held
that the three divine persons were really distinct not only from one another but also from the essence; this consequently resulted in a quaternity, since the divine essence thereby came to have an existence of its own. His doctrine was opposed by St. Bernard of Clairvaux and condemned in 1148 by the Council of Reims (cf. Denz-U, 389). A form of T. was also Joachim of Fiore (v.). Peter Lombard (v.), whom he reproached for having introduced a quaternity into God, Joachim of Fiore denied a common nature among the three divine persons, in accordance with the principles of nominalism, and consequently attributed to them a purely collective and moral unity. Since his Libellus de essentia Trinitatis contra Lombardum has been lost, his error is known from the condemnation issued by the Fourth Lateran Council in 1215 (cf. Denz-U, 431–33).
Toward the middle of the 19th century, A. Günther (v.) sought to apply the presuppositions of Hegelian philosophy to the mystery of the Most Holy Trinity, beginning from the identification of the concepts of personality and self-consciousness. His doctrine was condemned by Pius IX in 1857 (cf. Denz-U, 1655).