Reformed Principia
Reformed theology teaches us that God is the principium essendi of all disciplines, since it is from God alone that any and every discipline derives all that it is and has. On this view, the principium cognoscendi is the revelation of God, both natural and special. If that is the case, then every discipline is related directly to these two principia.
Scott Oliphint. Reasons for Faith: Philosophy in the Service of Theology (Phillipsburg, NJ: PR Publishing, 2006), 26