At every creed in the Mass we profess belief in God who spoke through the prophets. This in itself should spur us to reflection on the totality of the prophets' teachings, reflection too, in a spirit of great faith—fides quaerens intellectum—on the phenomenon of prophecy in general, and the mysterious facts relating to God's action in the world, the penetration of the divine and eternal into the world of sense and time. But our theology of prophecy must not be arbitrarily a priori; not need we be tempted to think that it is so in St Thomas's systematic treatises De Prophetia (de Veritate, 12; II-II, 171-174: Qdlbt 7, 14 ad 5. and 16). St Thomas was profoundly grounded in the Scriptures and more especially in the one thing necessary in Scriptural vestigation, that grasp of the doctrinal content of every book as of every word. We should strive to grasp a living, objective, reality: the utterance of God through the prophets, at a point in the history of the world, in and through contingent realities of flesh and blood.