# Summa Theologiae/Second Part of the Second Part/Question 171
## Treatise On Gratuitous Graces
### Question. 171 - OF PROPHECY (SIX ARTICLES)

After treating individually of all the virtues and vices that pertain to men of all conditions and estates, we must now consider those things which pertain especially to certain men. Now there is a triple difference between men as regards things connected with the soul's habits and acts. First, in reference to the various gratuitous graces, according to 1 Cor. 12:4, 7: "There are diversities of graces . . . and to one . . . by the Spirit is given the word of wisdom, to another the word of knowledge," etc. Another difference arises from the diversities of life, namely the active and the contemplative life, which correspond to diverse purposes of operation, wherefore it is stated (1 Cor. 12:4, 7) that "there are diversities of operations." For the purpose of operation in Martha, who "was busy about much serving," which pertains to the active life, differed from the purpose of operation in Mary, "who sitting . . . at the Lord's feet, heard His word" (Lk. 10:39,40), which pertains to the contemplative life. A third difference corresponds to the various duties and states of life, as expressed in Eph. 4:11, "And He gave some apostles; and some prophets; and other some evangelists; and other some pastors and doctors": and this pertains to diversity of ministries, of which it is written (1 Cor. 12:5): "There are diversities of ministries."
With regard to gratuitous graces, which are the first object to be considered, it must be observed that some of them pertain to knowledge, some to speech, and some to operation. Now all things pertaining to knowledge may be comprised under "prophecy," since prophetic revelation extends not only to future events relating to man, but also to things relating to God, both as to those which are to be believed by all and are matters of "faith," and as to yet higher mysteries, which concern the perfect and belong to "wisdom." Again, prophetic revelation is about things pertaining to spiritual substances, by whom we are urged to good or evil; this pertains to the "discernment of spirits." Moreover it extends to the direction of human acts, and this pertains to "knowledge," as we shall explain further on (Q[177]). Accordingly we must first of all consider prophecy, and rapture which is a degree of prophecy.
Prophecy admits of four heads of consideration: (1) its essence; (2) its cause; (3) the mode of prophetic knowledge; (4) the division of prophecy.
Under the first head there are six points of inquiry:
(1) Whether prophecy pertains to knowledge?
(2) Whether it is a habit?
(3) Whether it is only about future contingencies?
(4) Whether a prophet knows all possible matters of prophecy?
(5) Whether a prophet distinguishes that which he perceives by the gift of God, from that which he perceives by his own spirit?
(6) Whether anything false can be the matter of prophecy?

#### Art. 1 - Whether prophecy pertains to knowledge?

Objection 1: It would seem that prophecy does not pertain to knowledge. For it is written (Ecclus. 48:14) that after death the body of Eliseus prophesied, and further on (Ecclus. 49:18) it is said of Joseph that "his bones were visited, and after death they prophesied." Now no knowledge remains in the body or in the bones after death. Therefore prophecy does not pertain to knowledge.
Objection 2: Further, it is written (1 Cor. 14:3): "He that prophesieth, speaketh to men unto edification." Now speech is not knowledge itself, but its effect. Therefore it would seem that prophecy does not pertain to knowledge.
Objection 3: Further, every cognitive perfection excludes folly and madness. Yet both of these are consistent with prophecy; for it is written (Osee 9:7): "Know ye, O Israel, that the prophet was foolish and mad [*Vulg.: 'the spiritual man was mad']." Therefore prophecy is not a cognitive perfection.
Objection 4: Further, just as revelation regards the intellect, so inspiration regards, apparently, the affections, since it denotes a kind of motion. Now prophecy is described as "inspiration" or "revelation," according to Cassiodorus [*Prolog. super Psalt. i]. Therefore it would seem that prophecy does not pertain to the intellect more than to the affections.
On the contrary, It is written (1 Kings 9:9): "For he that is now called a prophet, in time past was called a seer." Now sight pertains to knowledge. Therefore prophecy pertains to knowledge.
I answer that, Prophecy first and chiefly consists in knowledge, because, to wit, prophets know things that are far [procul] removed from man's knowledge. Wherefore they may be said to take their name from {phanos}, "apparition," because things appear to them from afar. Wherefore, as Isidore states (Etym. vii, 8), "in the Old Testament, they were called Seers, because they saw what others saw not, and surveyed things hidden in mystery." Hence among heathen nations they were known as "vates, on account of their power of mind [vi mentis]," [*The Latin 'vates' is from the Greek {phates}, and may be rendered 'soothsayer'] (Etym. viii, 7).
Since, however, it is written (1 Cor. 12:7): "The manifestation of the Spirit is given to every man unto profit," and further on (1 Cor. 14:12): "Seek to abound unto the edification of the Church," it follows that prophecy consists secondarily in speech, in so far as the prophets declare for the instruction of others, the things they know through being taught of God, according to the saying of Is. 21:10, "That which I have heard of the Lord of hosts, the God of Israel, I have declared unto you." Accordingly, as Isidore says (Etym. viii, 7), "prophets" may be described as "proefatores [foretellers], because they tell from afar [porro fantur]," that is, speak from a distance, "and foretell the truth about things to come."
Now those things above human ken which are revealed by God cannot be confirmed by human reason, which they surpass as regards the operation of the Divine power, according to Mk. 16:20, "They . . . preached everywhere, the Lord working withal and confirming the word with signs that followed." Hence, thirdly, prophecy is concerned with the working of miracles, as a kind of confirmation of the prophetic utterances. Wherefore it is written (Dt. 34:10,11): "There arose no more a prophet in Israel like unto Moses, whom the Lord knew face to face, in all the signs and wonders."
Reply to Objection 1: These passages speak of prophecy in reference to the third point just mentioned, which regards the proof of prophecy.
Reply to Objection 2: The Apostle is speaking there of the prophetic utterances.
Reply to Objection 3: Those prophets who are described as foolish and mad are not true but false prophets, of whom it is said (Jer. 3:16): "Hearken not to the words of the prophets that prophesy to you, and deceive you; they speak a vision of their own heart, and not out of the mouth of the Lord," and (Ezech. 13:3): "Woe to the foolish prophets, that follow their own spirit, and see nothing."
Reply to Objection 4: It is requisite to prophecy that the intention of the mind be raised to the perception of Divine things: wherefore it is written (Ezech. 2:1): "Son of man, stand upon thy feet, and I will speak to thee." This raising of the intention is brought about by the motion of the Holy Ghost, wherefore the text goes on to say: "And the Spirit entered into me . . . and He set me upon my feet." After the mind's intention has been raised to heavenly things, it perceives the things of God; hence the text continues: "And I heard Him speaking to me." Accordingly inspiration is requisite for prophecy, as regards the raising of the mind, according to Job 32:8, "The inspiration of the Almighty giveth understanding": while revelation is necessary, as regards the very perception of Divine things, whereby prophecy is completed; by its means the veil of darkness and ignorance is removed, according to Job 12:22, "He discovereth great things out of darkness."

#### Art. 2 - Whether prophecy is a habit?

Objection 1: It would seem that prophecy is a habit. For according to Ethic. ii, 5, "there are three things in the soul, power, passion, and habit." Now prophecy is not a power, for then it would be in all men, since the powers of the soul are common to them. Again it is not a passion, since the passions belong to the appetitive faculty, as stated above (FS, Q[22] , A[2]); whereas prophecy pertains principally to knowledge, as stated in the foregoing Article. Therefore prophecy is a habit.
Objection 2: Further, every perfection of the soul, which is not always in act, is a habit. Now prophecy is a perfection of the soul; and it is not always in act, else a prophet could not be described as asleep. Therefore seemingly prophecy is a habit.
Objection 3: Further, prophecy is reckoned among the gratuitous graces. Now grace is something in the soul, after the manner of a habit, as stated above (FS, Q[110], A[2]). Therefore prophecy is a habit.
On the contrary, A habit is something "whereby we act when we will," as the Commentator [*Averroes or Ibn Roshd, 1120-1198] says (De Anima iii). But a man cannot make use of prophecy when he will, as appears in the case of Eliseus (4 Kings 3:15), "who on Josaphat inquiring of him concerning the future, and the spirit of prophecy failing him, caused a minstrel to be brought to him, that the spirit of prophecy might come down upon him through the praise of psalmody, and fill his mind with things to come," as Gregory observes (Hom. i super Ezech.). Therefore prophecy is not a habit.
I answer that, As the Apostle says (Eph. 5:13), "all that is made manifest is light," because, to wit, just as the manifestation of the material sight takes place through material light, so too the manifestation of intellectual sight takes place through intellectual light. Accordingly manifestation must be proportionate to the light by means of which it takes place, even as an effect is proportionate to its cause. Since then prophecy pertains to a knowledge that surpasses natural reason, as stated above (A[1]), it follows that prophecy requires an intellectual light surpassing the light of natural reason. Hence the saying of Micah 7:8: "When I sit in darkness, the Lord is my light." Now light may be in a subject in two ways: first, by way of an abiding form, as material light is in the sun, and in fire; secondly, by way of a passion, or passing impression, as light is in the air. Now the prophetic light is not in the prophet's intellect by way of an abiding form, else a prophet would always be able to prophesy, which is clearly false. For Gregory says (Hom. i super Ezech.): "Sometimes the spirit of prophecy is lacking to the prophet, nor is it always within the call of his mind, yet so that in its absence he knows that its presence is due to a gift." Hence Eliseus said of the Sunamite woman (4 Kings 4:27): "Her soul is in anguish, and the Lord hath hid it from me, and hath not told me." The reason for this is that the intellectual light that is in a subject by way of an abiding and complete form, perfects the intellect chiefly to the effect of knowing the principle of the things manifested by that light; thus by the light of the active intellect the intellect knows chiefly the first principles of all things known naturally. Now the principle of things pertaining to supernatural knowledge, which are manifested by prophecy, is God Himself, Whom the prophets do not see in His essence, although He is seen by the blessed in heaven, in whom this light is by way of an abiding and complete form, according to Ps. 35:10, "In Thy light we shall see light."
It follows therefore that the prophetic light is in the prophet's soul by way of a passion or transitory impression. This is indicated Ex. 33:22: "When my glory shall pass, I will set thee in a hole of the rock," etc., and 3 Kings 19:11: "Go forth and stand upon the mount before the Lord; and behold the Lord passeth," etc. Hence it is that even as the air is ever in need of a fresh enlightening, so too the prophet's mind is always in need of a fresh revelation; thus a disciple who has not yet acquired the principles of an art needs to have every detail explained to him. Wherefore it is written (Is. 1:4): "In the morning He wakeneth my ear, so that I may hear Him as a master." This is also indicated by the very manner in which prophecies are uttered: thus it is stated that "the Lord spake to such and such a prophet," or that "the word of the Lord," or "the hand of the Lord was made upon him."
But a habit is an abiding form. Wherefore it is evident that, properly speaking, prophecy is not a habit.
Reply to Objection 1: This division of the Philosopher's does not comprise absolutely all that is in the soul, but only such as can be principles of moral actions, which are done sometimes from passion, sometimes from habit, sometimes from mere power, as in the case of those who perform an action from the judgment of their reason before having the habit of that action.
However, prophecy may be reduced to a passion, provided we understand passion to denote any kind of receiving, in which sense the Philosopher says (De Anima iii, 4) that "to understand is, in a way, to be passive." For just as, in natural knowledge, the possible intellect is passive to the light of the active intellect, so too in prophetic knowledge the human intellect is passive to the enlightening of the Divine light.
Reply to Objection 2: Just as in corporeal things, when a passion ceases, there remains a certain aptitude to a repetition of the passion---thus wood once ignited is more easily ignited again, so too in the prophet's intellect, after the actual enlightenment has ceased, there remains an aptitude to be enlightened anew---thus when the mind has once been aroused to devotion, it is more easily recalled to its former devotion. Hence Augustine says (De orando Deum. Ep. cxxx, 9) that our prayers need to be frequent, "lest devotion be extinguished as soon as it is kindled."
We might, however, reply that a person is called a prophet, even while his prophetic enlightenment ceases to be actual, on account of his being deputed by God, according to Jer. 1:5, "And I made thee a prophet unto the nations."
Reply to Objection 3: Every gift of grace raises man to something above human nature, and this may happen in two ways. First, as to the substance of the act---for instance, the working of miracles, and the knowledge of the uncertain and hidden things of Divine wisdom---and for such acts man is not granted a habitual gift of grace. Secondly, a thing is above human nature as to the mode but not the substance of the act---for instance to love God and to know Him in the mirror of His creatures---and for this a habitual gift of grace is bestowed.

#### Art. 3 - Whether prophecy is only about future contingencies?

Objection 1: It would seem that prophecy is only about future contingencies. For Cassiodorus says [*Prol. super Psalt. i] that "prophecy is a Divine inspiration or revelation, announcing the issue of things with unchangeable truth." Now issues pertain to future contingencies. Therefore the prophetic revelation is about future contingencies alone.
Objection 2: Further, according to 1 Cor. 12, the grace of prophecy is differentiated from wisdom and faith, which are about Divine things; and from the discernment of spirits, which is about created spirits; and from knowledge, which is about human things. Now habits and acts are differentiated by their objects, as stated above (FS, Q[54], A[2]). Therefore it seems that the object of prophecy is not connected with any of the above. Therefore it follows that it is about future contingencies alone.
Objection 3: Further, difference of object causes difference of species, as stated above (FS, Q[54], A[2]). Therefore, if one prophecy is about future contingencies, and another about other things, it would seem to follow that these are different species of prophecy.
On the contrary, Gregory says (Hom. i super Ezech.) that some prophecies are "about the future, for instance (Is. 7:14), 'Behold a virgin shall conceive, and bear a son'"; some are "about the past, as (Gn. 1:1), 'In the beginning God created heaven and earth'"; some are "about the present," as (1 Cor. 14:24,25), "If all prophesy, and there come in one that believeth not . . . the secrets of his heart are made manifest." Therefore prophecy is not about future contingencies alone.
I answer that, A manifestation made by means of a certain light can extend to all those things that are subject to that light: thus the body's sight extends to all colors, and the soul's natural knowledge extends to whatever is subject to the light of the active intellect. Now prophetic knowledge comes through a Divine light, whereby it is possible to know all things both Divine and human, both spiritual and corporeal; and consequently the prophetic revelation extends to them all. Thus by the ministry of spirits a prophetic revelation concerning the perfections of God and the angels was made to Is. 6:1, where it is written, "I saw the Lord sitting upon a throne high and elevated." Moreover his prophecy contains matters referring to natural bodies, according to the words of Is. 40:12, "Who hath measured the waters in the hollow of His hand," etc. It also contains matters relating to human conduct, according to Is. 58:1, "Deal thy bread to the hungry," etc.; and besides this it contains things pertaining to future events, according to Is. 47:9, "Two things shall come upon thee suddenly in one day, barrenness and widowhood."
Since, however, prophecy is about things remote from our knowledge, it must be observed that the more remote things are from our knowledge the more pertinent they are to prophecy. Of such things there are three degrees. One degree comprises things remote from the knowledge, either sensitive or intellective, of some particular man, but not from the knowledge of all men; thus a particular man knows by sense things present to him locally, which another man does not know by human sense, since they are removed from him. Thus Eliseus knew prophetically what his disciple Giezi had done in his absence (4 Kings 5:26), and in like manner the secret thoughts of one man are manifested prophetically to another, according to 1 Cor. 14:25; and again in this way what one man knows by demonstration may be revealed to another prophetically.
The second degree comprises those things which surpass the knowledge of all men without exception, not that they are in themselves unknowable, but on account of a defect in human knowledge; such as the mystery of the Trinity, which was revealed by the Seraphim saying: "Holy, Holy, Holy," etc. (Is. 6:3).
The last degree comprises things remote from the knowledge of all men, through being in themselves unknowable; such are future contingencies, the truth of which is indeterminate. And since that which is predicated universally and by its very nature, takes precedence of that which is predicated in a limited and relative sense, it follows that revelation of future events belongs most properly to prophecy, and from this prophecy apparently takes its name. Hence Gregory says (Hom. i super Ezech.): "And since a prophet is so called because he foretells the future, his name loses its significance when he speaks of the past or present."
Reply to Objection 1: Prophecy is there defined according to its proper signification; and it is in this sense that it is differentiated from the other gratuitous graces.
Reply to Objection 2: This is evident from what has just been said. We might also reply that all those things that are the matter of prophecy have the common aspect of being unknowable to man except by Divine revelation; whereas those that are the matter of "wisdom," "knowledge," and the "interpretation of speeches," can be known by man through natural reason, but are manifested in a higher way through the enlightening of the Divine light. As to "faith," although it is about things invisible to man, it is not concerned with the knowledge of the things believed, but with a man's certitude of assent to things known by others.
Reply to Objection 3: The formal element in prophetic knowledge is the Divine light, which being one, gives unity of species to prophecy, although the things prophetically manifested by the Divine light are diverse.

#### Art. 4 - Whether by the Divine revelation a prophet knows all that can be known prophetically?

Objection 1: It would seem that by the Divine revelation a prophet knows all that can be known prophetically. For it is written (Amos 3:7): "The Lord God doth nothing without revealing His secret to His servants the prophets." Now whatever is revealed prophetically is something done by God. Therefore there is not one of them but what is revealed to the prophet.
Objection 2: Further, "God's works are perfect" (Dt. 32:4). Now prophecy is a "Divine revelation," as stated above (A[3]). Therefore it is perfect; and this would not be so unless all possible matters of prophecy were revealed prophetically, since "the perfect is that which lacks nothing" (Phys. iii, 6). Therefore all possible matters of prophecy are revealed to the prophet.
Objection 3: Further, the Divine light which causes prophecy is more powerful than the right of natural reason which is the cause of human science. Now a man who has acquired a science knows whatever pertains to that science; thus a grammarian knows all matters of grammar. Therefore it would seem that a prophet knows all matters of prophecy.
On the contrary, Gregory says (Hom. i super Ezech.) that "sometimes the spirit of prophecy indicates the present to the prophet's mind and nowise the future; and sometimes it points not to the present but to the future." Therefore the prophet does not know all matters of prophecy.
I answer that, Things which differ from one another need not exist simultaneously, save by reason of some one thing in which they are connected and on which they depend: thus it has been stated above (FS, Q[65], AA[1],2) that all the virtues must needs exist simultaneously on account of prudence and charity. Now all the things that are known through some principle are connected in that principle and depend thereon. Hence he who knows a principle perfectly, as regards all to which its virtue extends, knows at the same time all that can be known through that principle; whereas if the common principle is unknown, or known only in a general way, it does not follow that one knows all those things at the same time, but each of them has to be manifested by itself, so that consequently some of them may be known, and some not.
Now the principle of those things that are prophetically manifested by the Divine light is the first truth, which the prophets do not see in itself. Wherefore there is no need for their knowing all possible matters of prophecy; but each one knows some of them according to the special revelation of this or that matter.
Reply to Objection 1: The Lord reveals to the prophets all things that are necessary for the instruction of the faithful; yet not all to every one, but some to one, and some to another.
Reply to Objection 2: Prophecy is by way of being something imperfect in the genus of Divine revelation: hence it is written (1 Cor. 13:8) that "prophecies shall be made void," and that "we prophesy in part," i.e. imperfectly. The Divine revelation will be brought to its perfection in heaven; wherefore the same text continues (1 Cor. 113:10): "When that which is perfect is come, that which is in part shall be done away." Consequently it does not follow that nothing is lacking to prophetic revelation, but that it lacks none of those things to which prophecy is directed.
Reply to Objection 3: He who has a science knows the principles of that science, whence whatever is pertinent to that science depends; wherefore to have the habit of a science perfectly, is to know whatever is pertinent to that science. But God Who is the principle of prophetic knowledge is not known in Himself through prophecy; wherefore the comparison fails.

#### Art. 5 - Whether the prophet always distinguishes what he says by his own spirit from what he says by the prophetic spirit?

Objection 1: It would seem that the prophet always distinguishes what he says by his own spirit from what he says by the prophetic spirit. For Augustine states (Confess. vi, 13) that his mother said "she could, through a certain feeling, which in words she could not express, discern betwixt Divine revelations, and the dreams of her own soul." Now prophecy is a Divine revelation, as stated above (A[3]). Therefore the prophet always distinguishes what he says by the spirit of prophecy, from what he says by his own spirit.
Objection 2: Further, God commands nothing impossible, as Jerome [*Pelagius. Ep. xvi, among the supposititious works of St. Jerome] says. Now the prophets were commanded (Jer. 23:28): "The prophet that hath a dream, let him tell a dream; and he that hath My word, let him speak My word with truth." Therefore the prophet can distinguish what he has through the spirit of prophecy from what he sees otherwise.
Objection 3: Further, the certitude resulting from a Divine light is greater than that which results from the light of natural reason. Now he that has science, by the light of natural reason knows for certain that he has it. Therefore he that has prophecy by a Divine light is much more certain that he has it.
On the contrary, Gregory says (Hom. i super Ezech.): "It must be observed that sometimes the holy prophets, when consulted, utter certain things by their own spirit, through being much accustomed to prophesying, and think they are speaking by the prophetic spirit."
I answer that, The prophet's mind is instructed by God in two ways: in one way by an express revelation, in another way by a most mysterious instinct to "which the human mind is subjected without knowing it," as Augustine says (Gen. ad lit. ii, 17). Accordingly the prophet has the greatest certitude about those things which he knows by an express revelation, and he has it for certain that they are revealed to him by God; wherefore it is written (Jer. 26:15): "In truth the Lord sent me to you, to speak all these words in your hearing." Else, were he not certain about this, the faith which relies on the utterances of the prophet would not be certain. A sign of the prophet's certitude may be gathered from the fact that Abraham being admonished in a prophetic vision, prepared to sacrifice his only-begotten son, which he nowise would have done had he not been most certain of the Divine revelation.
On the other hand, his position with regard to the things he knows by instinct is sometimes such that he is unable to distinguish fully whether his thoughts are conceived of Divine instinct or of his own spirit. And those things which we know by Divine instinct are not all manifested with prophetic certitude, for this instinct is something imperfect in the genus of prophecy. It is thus that we are to understand the saying of Gregory. Lest, however, this should lead to error, "they are very soon set aright by the Holy Ghost [*For instance, cf. 2 Kings 7:3 seqq.], and from Him they hear the truth, so that they reproach themselves for having said what was untrue," as Gregory adds (Hom. i super Ezech.).
The arguments set down in the first place consider the revelation that is made by the prophetic spirit; wherefore the answer to all the objections is clear.

#### Art. 6 - Whether things known or declared prophetically can be false?

Objection 1: It would seem that things known or declared prophetically can be false. For prophecy is about future contingencies, as stated above (A[3] ). Now future contingencies may possibly not happen; else they would happen of necessity. Therefore the matter of prophecy can be false.
Objection 2: Further, Isaias prophesied to Ezechias saying (Is. 38:1): "Take order with thy house, for thou shalt surely die, and shalt not live," and yet fifteen years were added to his life (4 Kings 20:6). Again the Lord said (Jer. 18:7,8): "I will suddenly speak against a nation and against a kingdom, to root out and to pull down and to destroy it. If that nation against which I have spoken shall repent of their evil, I also will repent of the evil that I have thought to do them." This is instanced in the example of the Ninevites, according to Jn. 3:10: "The Lord [Vulg.: 'God'] had mercy with regard to the evil which He had said that He would do to them, and He did it not." Therefore the matter of prophecy can be false.
Objection 3: Further, in a conditional proposition, whenever the antecedent is absolutely necessary, the consequent is absolutely necessary, because the consequent of a conditional proposition stands in the same relation to the antecedent, as the conclusion to the premises in a syllogism, and a syllogism whose premises are necessary always leads to a necessary conclusion, as we find proved in I Poster. 6. But if the matter of a prophecy cannot be false, the following conditional proposition must needs be true: "If a thing has been prophesied, it will be." Now the antecedent of this conditional proposition is absolutely necessary, since it is about the past. Therefore the consequent is also necessary absolutely; yet this is unfitting, for then prophecy would not be about contingencies. Therefore it is untrue that the matter of prophecy cannot be false.
On the contrary, Cassiodorus says [*Prol. in Psalt. i] that "prophecy is a Divine inspiration or revelation, announcing the issue of things with invariable truth." Now the truth of prophecy would not be invariable, if its matter could be false. Therefore nothing false can come under prophecy.
I answer that, As may be gathered from what has been said (AA[1],3,5), prophecy is a kind of knowledge impressed under the form of teaching on the prophet's intellect, by Divine revelation. Now the truth of knowledge is the same in disciple and teacher since the knowledge of the disciple is a likeness of the knowledge of the teacher, even as in natural things the form of the thing generated is a likeness of the form of the generator. Jerome speaks in this sense when he says [*Comment. in Daniel ii, 10] that "prophecy is the seal of the Divine foreknowledge." Consequently the same truth must needs be in prophetic knowledge and utterances, as in the Divine knowledge, under which nothing false can possibly come, as stated in the FP, Q[16], A[8]. Therefore nothing false can come under prophecy.
Reply to Objection 1: As stated in the FP, Q[14], A[13] the certitude of the Divine foreknowledge does not exclude the contingency of future singular events, because that knowledge regards the future as present and already determinate to one thing. Wherefore prophecy also, which is an "impressed likeness" or "seal of the Divine foreknowledge," does not by its unchangeable truth exclude the contingency of future things.
Reply to Objection 2: The Divine foreknowledge regards future things in two ways. First, as they are in themselves, in so far, to wit, as it sees them in their presentiality: secondly, as in their causes, inasmuch as it sees the order of causes in relation to their effects. And though future contingencies, considered as in themselves, are determinate to one thing, yet, considered as in their causes, they are not so determined but that they can happen otherwise. Again, though this twofold knowledge is always united in the Divine intellect, it is not always united in the prophetic revelation, because an imprint made by an active cause is not always on a par with the virtue of that cause. Hence sometimes the prophetic revelation is an imprinted likeness of the Divine foreknowledge, in so far as the latter regards future contingencies in themselves: and such things happen in the same way as foretold, for example this saying of Is. 7:14: "Behold a virgin shall conceive." Sometimes, however, the prophetic revelation is an imprinted likeness of the Divine foreknowledge as knowing the order of causes to effects; and then at times the event is otherwise than foretold. Yet the prophecy does not cover a falsehood, for the meaning of the prophecy is that inferior causes, whether they be natural causes or human acts, are so disposed as to lead to such a result. In this way we are to understand the saying of Is. 38:1: "Thou shalt die, and not live"; in other words, "The disposition of thy body has a tendency to death": and the saying of Jonah 3:4, "Yet forty days, and Nineveh shall be destroyed," that is to say, "Its merits demand that it should be destroyed." God is said "to repent," metaphorically, inasmuch as He bears Himself after the manner of one who repents, by "changing His sentence, although He changes not His counsel" [*Cf. FP, Q[19], A[7], ad 2].
Reply to Objection 3: Since the same truth of prophecy is the same as the truth of Divine foreknowledge, as stated above, the conditional proposition: "If this was prophesied, it will be," is true in the same way as the proposition: "If this was foreknown, it will be": for in both cases it is impossible for the antecedent not to be. Hence the consequent is necessary, considered, not as something future in our regard, but as being present to the Divine foreknowledge, as stated in the FP, Q[14], A[13], ad 2.