Article 3 — Whether things that are impossible for nature are possible for God

The third point of inquiry is whether things that are impossible for nature are possible for God. (Parallel texts: ST I.25.4; SCG II.25; In I Sent. 42.2; Quodlibet V, q. 2, a. 1; Commentary on the Nicomachean Ethics, bk. 4, lect. 2, 5.)

Obj. 1: And it seems that this is not so. For the Gloss (The Marietti edition notes that a “gloss,” according to Hugh of Pisa (d. 1210 AD), differs from a commentary inasmuch as a commentary “is an exposition that considers the meaning of words, not how they are joined together.” A gloss, on the other hand, is “an exposition of the sentence and the letter itself, which pays attention not only to the sentence but also to the words.” And so it is called a glosa, as if a glossa, that is, a tongue or language, because just so does the language of the teacher compare, explain, and devote itself to explaining the letter and developing its meaning. (Cf. Robert, Les ecoles et l’enseignement de la theologie pendant la premiere moitie de XII siècle [Paris: 1909], 55, n. 2). In the works of Thomas Aquinas, the Gloss indicates a certain interpretation of Sacred Scripture. The two main glosses Aquinas worked with are the Glossae ordinariae and the Glossae interlineares. The Glossa ordinaria, compiled by Walafrid Strabo (d. 849 AD), is mostly drawn from the works of the fathers; it was considered as a theological or historical commentary and was written on the sides or margins of the text (from which also it was called the marginal Gloss). The author of the interlinear Gloss is Anselm de Laon (d. 1117 AD); written between the lines of the Sacred Text (and hence, “interlinear”), this Gloss is focused on the meaning of the words themselves.) on Romans 11:24 (Glossa ordinaria, in Bibliorum Sacrorum cum Glossa ordinaria iam ante quidem a Strabo Fulgensi, collecta: nunc autem novis patrum, cum Graecorum, tum Latinorum expositionibus locupletata cum postilla Nicolai Lyrani (Venice: 1603), vol. 6, p. 150, at Romans 11:24; see also PL 114:508.) says that, since God is the author of nature, he cannot do what is contrary to nature. Now, things that are impossible for nature are contrary to nature. Therefore, God cannot do them.

Obj. 2: As all that is necessary in nature can be demonstrated, so whatsoever is impossible in nature can be disproved by demonstration. Now, every conclusion of a demonstration involves the principles of that demonstration. But within all principles of demonstration is included the principle that affirmation and denial cannot be both true at the same time. Therefore, this principle is involved whenever a thing is impossible to nature. But according to the respondent, God cannot make an affirmation and a denial be true at the same time. Therefore, he cannot do what is naturally impossible.

Obj. 3: There are two principles under God: reason and nature. Now, God cannot do what is impossible to reason—for instance, that a genus be not predicated of its species. Neither, therefore, can he do what is impossible to nature.

Obj. 4: As false and true are in relation to knowledge, so are possible and impossible to operation. Now, God cannot know what is false in nature; therefore, he cannot do what is impossible in nature.

Obj. 5: When there is a likeness of one and all, what is proved of one is understood to be proved of all; thus, if it be proved of one triangle that the three angles equal two right angles, it is understood to be proved of all triangles. Now, a like account seems to be given of everything impossible: that God is capable of doing it and is not capable of doing it, both on the side of the doer (since God’s power is infinite) and on the side of the thing done (since everything has an obediential potency to God). Therefore, if there be anything impossible to nature that he cannot do, it seems he can do nothing impossible.

Obj. 6: It is written that God is faithful; he cannot deny himself (2 Tim 2:13). But he would deny himself, says the Gloss, (Glossa interlinearis, in Bibliorum Sacrorum cum Glossa ordinaria iam ante quidem a Strabo Fulgensi, collecta: nunc autem novis patrum, cum Graecorum, tum Latinorum expositionibus locupletata cum postilla Nicolai Lyrani (Venice: 1603), vol. 6, pp. 739–40, at 2 Tim 2:13.) if he did not fulfill his promise. Now, as God’s promise comes from God, so is all truth from God, because all truth, by whomsoever uttered, is from the Holy Spirit, according to a Gloss of Ambrose (Ambrosiaster (Pseudo-Ambrose, 4th century AD), Pauline Commentary, at 1 Cor 12:3 (PL 17:258–59).) on 1 Corinthians 12:3, no man can say, “Jesus is Lord,” but by the Holy Spirit. Therefore, God cannot act counter to the truth. He would, however, if he were to do what is impossible. Therefore, he cannot do what is impossible to nature.

Obj. 7: Anselm says that God cannot do what is in the least way unbecoming. (Anselm of Canterbury, Cur Deus homo 1.20 (PL 158:392–93).) Now, it would be unbecoming for an affirmation and a denial to be true at the same time, because the intellect would then be in bondage. Therefore, God cannot do this; consequently, he cannot do whatever is impossible to nature.

Obj. 8: No artist can work counter to his own art, since the principle of his work is the art. But God would be working against his art if he were to do what is impossible in nature, because the order of nature, in relation to which that thing is impossible, is according to the divine art. Therefore, God cannot do what is naturally impossible.

Obj. 9: That which is impossible in itself is more impossible than what is impossible accidentally. Now, God cannot do what is accidentally impossible—for instance, that what has been should not have been. Thus Jerome says that while God can do other things, he cannot make a virgin of one who has lost virginity. (Jerome (ca. 347–419 AD), Epistle 22.5, Ad Eustochium, De custodia virginitatis (PL 22:397).) See also Augustine and the Philosopher. (Augustine, Against Faustus the Manichee 26 (PL 42:479–84); Aristotle, Nicomachean Ethics 5.5, 1133b18; 6.2, 1139b5.) Therefore, God cannot do what is through itself impossible in its nature.

On the contrary (1), it is written: no word shall be impossible with God (Luke 1:37).

Furthermore (2), any power that can do one thing, but not another, is limited. If, then, God can do what is possible to nature but not that which is impossible, or some that are impossible and not others, it would seem that his is a limited power, which is contrary to what we have proved above. Therefore, God cannot do what is naturally impossible.

Furthermore (3), that which is not limited by anything in reality cannot be hindered by anything in reality. Now, God is not limited by anything in reality. Therefore, nothing in reality can impede him, and thus the truth of the principle that affirmation and denial cannot be simultaneous cannot impede what God can do. The same applies to all other principles.

Furthermore (4), privation is not susceptive of degrees. But “impossible” connotes privation of power. Therefore, if God can do one impossible thing—for instance, restore sight to the blind—it would seem that he can do all.

Furthermore (5), all resistance is by reason of some opposition. But nothing is opposed to God’s power, as shown above. Therefore, nothing can resist it. And so he can do all things that are impossible.

Furthermore (6), as blindness is opposed to sight, so is virginity opposed to giving birth. But God made a virgin give birth and yet remain a virgin. Therefore, for the same reason he can make a blind man see while remaining blind, and he can make both an affirmation and a denial be true at the same time, and consequently, he can do all impossible things.

Furthermore (7), it is more difficult to unite diverse substantial forms than diverse accidental forms. Now, God united together the most diverse substantial forms, namely, the divine and human, which differ as uncreated and created. Much more, therefore, can he unite two accidental forms, so that the same thing be black and white. And thus the same conclusion follows as before.

Furthermore (8), if we remove from a defined thing something that falls in its definition, it will follow that contraries are true simultaneously—for instance, that a man is not rational. Now, to be bounded by two points is in the definition of a straight line. Therefore, if anyone were to remove this from a straight line, it would follow that two contraries are simultaneously true. Now, God did this when he came in to his disciples while the doors were closed, since two bodies were then in the same place, and thus, it follows both that two lines were bounded by only two points, and that each line was bounded at two points. Consequently, God can make an affirmation and a denial true at the same time, and therefore, he can do all things that are impossible.

I answer that, according to the Philosopher, a thing is said to be possible or impossible in three ways. (Aristotle, Metaphysics 5.12, 1019b21–27.)

First, in respect of an active or passive power: thus, it is possible for a man to walk according to his power of advancing, but it is impossible for him to fly.

Second, not in respect of a power but in its very self: thus, we say that a thing is “possible” if it is not impossible to be, and that a thing is “impossible” if it is necessary that it not be.

Third, a thing is said to be “possible” in respect of mathematical power, as we say in geometry. Thus, a certain line is commensurable in power because its square is commensurable. (See Euclid, Elements, bk. 10, definitions 1–4.)

Omitting this last kind of possibility, let us consider the other two.

It must be noted that a thing is said to be impossible in its very self, and not in respect of any power, by reason of the disharmony of terms. Now, every disharmony of terms is in the account of an opposition, and every opposition connotes affirmation and denial, as is proved in Metaphysics 10; (Aristotle, Metaphysics 10.4, 1055a33–b11.) whence in every such impossible thing there is implied an affirmation and a denial being simultaneous.

That this cannot be ascribed to any active power is evident as follows. All active power is consequent upon the actuality and entity of the thing to which it belongs. Now, every agent is naturally apt to produce its like; hence, every action of an active power terminates in being. For although at times non-being is the result of an action—such as, for instance, corruption—this is only insofar as the being of one thing is incompatible with the being of another; for example, the being of a hot thing is incompatible with the being of a cold thing; hence, heat, from its principal intention, generates heat, but that it destroys cold is by way of consequence. Now, that an affirmation and a denial be true at the same time cannot have the account of a being, nor even of a non-being, since to-be removes not-to-be, and not-to-be removes to-be. Consequently, it can be the terminus of an action’s active power neither principally nor by way of consequence.

On the other hand, a thing is said to be impossible in respect of a certain power in two ways.

First, on account of a defect in the power itself from its very self, in that the effect is beyond its reach, as when a natural agent cannot transform a certain matter.

Second, when the impossibility arises from without, as in the case of a power that is hindered or bound.

Accordingly, “impossible to occur” is said in three ways.

First, by reason of a defect in the active power, whether in transforming matter or in any other way.

Second, by reason of something resisting or impeding.

Third, because that which is said to be impossible to occur cannot be the terminus of an action.

Those things, then, which are impossible for nature in the first or second modes are possible for God. For his power, since it is infinite, is subject to no defect, nor is there any matter that he cannot transform at will, since his power is irresistible. On the other hand, God cannot do those things that are called impossible in the third mode, since he is maximally act and the principal being; hence, principally, his action cannot terminate except at being, and at non-being in a consequent way. Therefore, he cannot make an affirmation and a denial be true at the same time, nor any of those things which involve such an impossibility. Nor is he said to be unable to do these things on account of a deficiency of his power, but on account of a deficiency of possibility, that which defects from the account of the possible. And on account of this some say, “God can do it, but it cannot be done.”

Reply Obj. 1: Augustine’s words quoted in the Gloss do not mean that God is unable to do otherwise than nature does, since he often acts contrary to the customary course of nature; but that whatever he does in things is not contrary to nature, but is by nature for them, in that he is the one who founds and orders nature. For in natural realities we observe that when a lower body is moved by a higher, the movement is natural to it, although it may not seem congruent to the movement that it has naturally from its very self. In this way, the tidal ebb and flow of the sea is caused by the moon; and this movement is natural to it (as the Commentator observes) even though the natural motion of water according to its very self is to be borne downward. (Averroes, De caelo et mundi 1.3, LC 14va1–15rb11 TC 20, 270a12–22.) And in this way, all created things have as natural, as it were, whatever occurs in them from God. And therefore, we distinguish two kinds of potency in them: a natural potency in respect of their proper operations and movements, and another that is called a “potency of obedience,” as regards the things that they receive from God.

Reply Obj. 2: Every impossibility involves an affirmation and a denial being simultaneous insofar as it is impossible. Those things, however, that are impossible by reason of a deficiency of the natural power (such as a blind man becoming one who sees, and the like), because they are not impossible according to their very selves, do not imply such an impossibility according to their very selves but only in relation to the natural power to which they are impossible. Thus, were we to say that nature can make a blind man see, the statement would involve an impossibility of this kind, because nature’s power is bounded in relation to something, whereas the effect that is being ascribed to it is beyond this.

Reply Obj. 3: The impossibilities of rational philosophy are not in relation to a certain power but to their very selves, because things that are in within rational philosophy are not applied to matter or to certain natural powers.

Reply Obj. 4: That which is false in its nature is false simply speaking. Hence there is no comparison.

Reply Obj. 5: There is not the same account of every impossibility, since some things are impossible in themselves, and some with respect to a certain power, as above stated. Nor does the fact that they stand in diverse ways to the divine power impede the divine power’s infinity or the creature’s obedience.

Reply Obj. 6: God does not destroy what is already true, because he does not make that which was true not to have been. But he does make that which otherwise would have been true, not to be true. Thus, when he raises a dead man to life, he makes it to be untrue that he is dead, which would have been true otherwise.

Or we may reply that there is no comparison, since were God not to keep his promise, it would follow that he is untruthful; but this does not follow if he undoes what he has done. For he has not decreed that whatever he does should always remain so, but he has decreed that he will keep his promise.

Reply Obj. 7: God cannot make an affirmation and a denial be true at the same time—not because it is unbecoming but for the reason stated above.

Reply Obj. 8: God’s art extends not only to the things made but to many others also. Hence, when he changes the course of nature in anything, he does not therefore act against his art.

Reply Obj. 9: That Socrates has not run if he has run is called “impossible accidentally” because Socrates’s running or not running, considered in itself, is contingent; yet, since it would imply that the past has not existed, it becomes impossible in itself. Hence, it is said to be impossible accidentally, that is, through some adventitious circumstance. But this circumstance is impossible according to its very self, and clearly involves a contradiction; for to say that a thing has been and that it has not been is contradictory, which would be the case if the past were made not to have been.

Reply Sed Contra 1: “Word” names not only what is uttered by the lips but also what is conceived in the mind. Now, the mind cannot conceive an affirmation and denial as true at the same time, and therefore it cannot conceive anything in which this is involved, as is proved in Metaphysics 4. (Aristotle, Metaphysics 4.3, 1005b18–35.) For because contrary opinions are things that belong to contrary things, according to the Philosopher, it would follow that the same person would have contrary opinions at the same time. Thus, it is not contrary to the angel’s word to say that God cannot do the above-mentioned kind of impossibility.

Reply Sed Contra 2: God cannot do this kind of impossibility because it defects from the account of the possible; and hence God’s power is not said to be limited even though he cannot do it.

Reply Sed Contra 3: God is said to be unable to do this not as though he were prevented by the free will, as stated above, but because this cannot be the terminus of an active power’s action.

Reply Sed Contra 4: Privation in reference to itself does not admit of more and less, but it can admit of this in respect of its cause. Thus, a man who has lost an eye is more blind than one who is prevented from seeing by some disease of the eye. In like manner, that which is impossible in reference to itself may be said to be more impossible than a thing which is impossible simply speaking.

Reply Sed Contra 5: As stated above, (Q. 1, a. 3, resp.) God is said to be unable to do this not because something prevents him, but for the reasons given.

Reply Sed Contra 6: Virginity is not opposed to giving birth the way that blindness to sight; rather, it is opposed to sexual coupling, without which nature cannot cause a child to be born, although God can.

Reply Sed Contra 7: The created and uncreated, though opposite, were not in Christ in the same respect but in respect of the different natures. Hence, it does not follow that God can make opposite things be in the same thing and in the same respect.

Reply Sed Contra 8: When Christ entered with the doors being closed, (John 20:26.) and two bodies were in the same place, nothing occurred contrary to the principles of geometry. For then on one side, not one but two lines terminated at two points of different bodies. Although two mathematical lines are not distinguishable except by their position, such that one cannot conceive two such lines to be in the same place, nevertheless, two natural lines are distinguishable by their subjects. Thus, with it granted that two bodies are in the same place, it follows that two lines are in the same place, as well as two points and two surfaces.