fides quaerens intellectum: Literally, “faith seeking understanding.” The phrase originated with Anselm in his Proslogion and was used to show the relationship of religious faith to human reason. For Anselm, matters of religion and theology are understood only by first believing them and then proceeding to gain an intellectual understanding of the things already believed. In other words, faith is both logically and chronologically prior to reason.1
1. Stanley J. Grenz, David Guretzki & Cherith Fee Nordling, Pocket Dictionary of Theological Terms (Downers Grove, IL: InterVarsity Press, 1999), p. 52.