Summa summae S. Thomae, Tomus III

[I say 1°, with St. Thomas, 2ae 2ae, q. 171, a. 1 : « Prophecy consists first and principally in cognition,. namely, that prophets know things distant and remote from human knowledge... Prophecy secondarily consists in speech, insofar as prophets announce to others, for their edification, the things they know by divine instruction, according to Isa., XXI, 10 : What I have heard from the Lord of hosts, the God of Israel, I have declared unto you. » Prophecy comes from two Greek words, προ, before, and φημί, I speak, and signifies in general an announcement made beforehand of an event. It is commonly defined thus : « A sure presentiment and prediction of some event which could not have been foreknown from natural causes. » Or more narrowly : « The manifestation of a future thing hidden from creatures. » From this notion of prophecy it is clear that three conditions are required for it to be truly and properly such, namely : 1° that it be a sure prediction, not conjectural ; 2° that it be a prediction of a future contingent thing, which accordingly can be known neither by art nor by any natural science whatever ; 3° that it be so determinate that the event is not accommodated to the prophecy, but rather the prophecy determines the event : that is, that it not be so vague, obscure, and equivocal as to fit any event whatsoever, and its application not arbitrary ; so that prophecy, which is a true miracle, supplies its own proof.

I say 2° : Prophecy is possible.

This is against the ancients and the more recent authors who denied the possibility of prophecy. Among the ancients were, on the testimony of Cicero¹, the Colophonian and Epicurus. The latter had no other reason for rejecting all divination than that he did not admit that mankind was of concern to the gods. Such was also the judgment of Carneades, as the same Cicero asserts². Among the more recent, Spinoza and the Socinians deny to God himself the faculty of foreseeing future things. Finally, all rationalists now deny that man can receive a prophetic spirit from God.

Proof. by reason. The possibility of prophecy reduces to these two questions : first, whether God can foreknow things future ; second, supposing the foreknowledge of things future, whether.

God can manifest them to man. But both of these are possible. Therefore.

Proof. of the first part, minor. The first is not only possible but necessary. For in God there is omniscience, and therefore foreknowledge, which is included in perfect and infinite science. If God did not have this foreknowledge, he would not be infinitely perfect under this respect, and consequently would not be God. And this knowledge in God is not properly foreknowledge, but simply knowledge. This is proved by St. Thomas, Iª p., q. 14, a. 13, o : « Since God knows all things, not only those which actually exist, but also those which are in his own power or in the creature's, and since some of these are contingent as to their future occurrence, it follows that God knows future contingents... Now God knows all contingents, not only as they are in their causes, but also as each of them actually is in itself. And although contingents come into actual existence successively, God does not know contingents successively in their being, as we do, but simultaneously, because his knowledge is measured by eternity, as is also his being. And eternity, existing whole and at once, embraces all time. Hence all things which are in time are present to God from eternity, not only by the reason that he has the notions of things present within himself, as some say, but because his gaze is directed from eternity upon all things as they stand in their presentiality. Hence it is manifest that contingents are infallibly known by God, inasmuch as they are subject to the divine sight according to their presentiality ; and yet they remain future contingents in comparison with their proximate causes. » Therefore.

It is confirmed by the manifold testimonies of Scripture, of which the following may suffice to cite. Heb., IV, 13 : All things are naked and open to his eyes. Ps., cxxxviii, 3 and 4 : You have understood my thoughts from afar... you have foreseen all my ways. Wis., VIII, 8 : She knows the signs and wonders before they come to pass, and the events of times and ages. The prophecies recorded in the Scriptures, which were certainly fulfilled even in the smallest particulars, demonstrate this possibility evidently from the fact itself.

Proof. of the second part, minor. If God could not manifest future things to man, the impediment would evidently stand only on the side of man, who would not be capable of such communication. But this incapacity cannot be admitted. Therefore. — Proof. of the minor. Man learns from man the things he does not know, and among these are many that learned men, aided by the natural light alone, foresaw as about to arise from their causes. But if it should please God, man can be taught by him no less, indeed much more, in the extraordinary way of inspiration, that is, of interior illumination whereby future contingents, naturally hidden, are opened up to him. Therefore.

It is confirmed by the consent of the human race; for it has always been the persuasion of men that some have received divine communications concerning things to come. Thence, among the pagans, oracles, divinations, auguries, and magical arts.]