Abstract

This chapter presents Anselm’s attempts to show that the doctrine that God is one yet threefold in nature is free from contradiction. In carrying out this project, Anselm is aware that he must avoid the heresies of Arianism, tritheism, and modalism. Following Augustine, Anselm models his account of the relations among Father, Son, and Holy Spirit as relations among memory, understanding, and will. In On the Incarnation of the Word Anselm reworks an analogy used in Augustine’s On Faith and the Creed. The Nile is spring, river, and lake, yet there are not three Niles. Anselm realizes that taken literally, the analogy leads to tritheism or the denial of God’s simplicity, and tries to improve on the analogy. However, Anselm is aware that improvement on the analogy can only yield dim, imperfect vestiges of the Trinity, which is a mystery beyond human understanding.