In preparation for an upcoming symposium talk on the Aristotelian-Thomistic understanding of chance and indeterminism in nature, I had the opportunity to read Cardinal Cajetan’s commentary on ST, Ia, q. 115, a. 6, where St. Thomas wonders “whether heavenly bodies impose necessity on things subject to their action?” This article and Cajetan’s commentary is used by De Koninck in his famous essays on chance and indeterminism, and is referenced by Anthony Andres in his helpful talk on this subject.
The below translation is a draft.
Cajetan on ST, Ia, q. 115, a. 6
(Leonine ed., vol. 5, pp. 547–551)
The [meaning of the] title is clear. In the body [of the article], there are four items: first, the question is set down as in part already solved, in part yet to be solved. Second, the part already solved is shown. Third, the part to be solved [is shown], and fourth, the conclusion answering the question is brought forward at the end.
[I. The solved part of the question: human action]
1. Since the first part is clear, regarding the second, it is said that this question is solved as to those things which are under [the power] of the heavenly bodies and which are also subject to human will. That is, namely, such things lead to a negative response to the question: The heavenly bodies do not impose necessity on those things subject to human action. The proof is that their action can be impeded by the will, because such willing is not subject to their action, since it does not follow the inclinations of the passions necessarily.
[II. The part of the question to be solved: natural things]
2. As to the third, there are four points. First, the difficulty of the question is stated, namely, that [it has to do with] the rest of natural things [other than human things]. The proof of this is that there appears in such things no principle no subject to the heavens, or free. Second, the argument on the affirmative side is set forth, based on two propositions:
(1) Everything that happens (namely, de novo) has a cause.
(2) Given a cause, the effect follows of necessity.
Third, the second proposition is examined using Aristotle. Fourth, the first [proposition is examined].
[II.A: Against proposition (2), that effects do not follow necessarily, given their cause]
3. The examination of the second proposition concludes that it is false as a universal claim, namely, because it does not hold among causes that are able to fail, and natural causes are such. The proof is that they attain their intended end for the most part [ut in pluribus], and not always, as is clear from Physics, Book II [see ch. 5, n. 1; St. Thomas, lect. 8].
Thereupon [the examination of St. Thomas] shows that such an exception, even if it obviates proposition (2) in itself and absolutely, it does not [do so] as applied to what was intended, considering the [following] argument. (a) A natural cause falls short for the lesser part [in paucioribus], as such it is due to some other cause hindering it from its proper effect; therefore, it necessarily fails. (b) Therefore either effect, namely the intended one and the one beside the intention, comes to be necessarily. The antecedent (a) is clear. The proof of the consequent (b): because the impediment itself comes about by necessity.
[II.A.i: Avicenna’s doubt answered]
4. Concerning the examination of proposition (2), namely, given a cause, the effect follows of necessity, a doubt arises on account of the argument of Avicenna [see Sufficient., I.13], that there is no exception [to be had in this case]. The cause under discussion is not an insufficient cause (seeing that it would be foolish to say so of such a thing), but a sufficient one. However, given a sufficient cause, and free causes being taken away (as is found in the natural things currently under discussion), it is unintelligible that the effect would not follow. And if something else is required, then the given cause was not sufficient, because what is sufficient does not need something else.
5. In reply: at present the discussion concerns per se and sufficient causes. When it is claimed “If, given the [cause] the effect does not follow, thus something else is required,” I deny that this follows. For it commits the fallacy of the consequent, for the non-following of the effect is able to occur due to something else, such as from the concourse of some other impediment. Whence, it is not due to the insufficiency of the burnable material that it must be concluded that burning does not follow, but due to the concourse of some other impediment to burning.
And if one insists against this that since such a concourse comes back to the insufficiency of the cause, because the impeded cause is not sufficient, the response is clear. According to the truth of the matter, it does not come back to the insufficiency of the cause absolutely, but the actual causality on which the impediment is brought to bear. Perhaps Avicenna was deceived in this way, since he did not distinguish between (i) the sufficiency of the cause which follows upon what belongs to the first act or form which is the principle of acting, and (ii) the sufficiency of the circumstances of the actual causality in respect of this, here and now, which follow upon what belongs to diverse occurrences. For it is certain that the effect necessarily follows upon the sufficient cause in this sense (ii), but not upon sense (i). Nevertheless, we are speaking about (i) in the current discussion. Therefore, Aristotle’s exception is a true one, such that there are certain per se and sufficient causes which bring on their effects not simply speaking but with a limitation, namely, [doing so] for the most part. In thus way, they do not necessarily bring on their effects absolutely speaking. And this is one root of contingency, as is said in On Interpretation, Book I [see ch. 9, n. 10; St. Thomas, lect. 14].
[II.A.ii: Two further doubts considered]
[(a) The doubts raised]
6. Concerning the difficulty raised in the text against the exception of Aristotle, that, granted it be true, nonetheless it does not remove the difficulty proposed [see above, n. 3], a twofold doubt arises. The first is because it seems false that a cause that fails for the lesser part always fails because of some hindering cause. Rather, this seems to be the Stoic error. The proof of this: Just as potency is to potency, so is act to act. But a potency failing for the lesser part is not a potency susceptible of being impeded, but conversely. For it is not that a natural cause is able to fail because it is able to be impeded, but the reverse: because it is able to fail, it is able to be impeded—for [what is] intrinsic is the reason for [what is] extrinsic, and not conversely. Therefore, the fall short in act is not by some actual impediment. Consequently, the cause is able to fail without some hindering cause.
The second doubt is ad hominem, namely against St. Thomas. If the denial of proposition (2) does nothing to advance the proposed [conclusion] (since given a cause able to fail and an hindering cause, the effect necessarily follows), what things are to be said on behalf of such a proposal, given the many times these two propositions are thus examined? For they are given here, in Summa contra Gentiles III.86, in Metaphysics Book VI [lect. 3], and in On Interpretation Book I [lect. 14], etc.
[(b) The doubts answered]
7. To the first doubt, what is assumed in the text is true, namely that a cause never fails unless on account of some hindering cause. To manifest this, note that to the extent that generable beings have an intrinsic potency to non-being (yet, which never passes into act unless some corruptive [cause] is present), to that degree the potency of failing in operating is intrinsic (and nevertheless does not pass into failing in act unless something causing that failure is present). The reason in both causes is the same, namely, because a passive potency does not pass into act unless it is moved by some active one. However, to be able not to be and to fail in operating belongs to passive potency, and thus it does not happen absent some cause.
And do not let it escape your notice that the potency to operate is active. Because to operate follows upon act, and thus the potency to operate is active. However, to fail in action follows upon imperfection, and thus the defective potency for whatsoever defect is reduced to some passive potency, as is clear from On the Heavens Book I [see ch. 12, n. 19; St. Thomas, lect. 22]. And these things are to be understood of the defect of action on the part of a cause which is intrinsic, which is what the objection is about. However, concerning its defect on the part of extrinsic [causes], it is clear that this arises due to some impediment—yet in what way will be said below.
8. Concerning the objection made above [see n. 6], the major premise is false. The reason is that the order of composition is contrary to the order of resolution, for those things which are prior by way of generation are last by way of corruption. Whence, in the proposed, since generable beings have a potency to non-being and to being corrupted by another, thus they are able to be corrupted because they are able not to be, and not conversely. Nevertheless, the act of corruption is naturally prior to non-being, since non-being is the terminus of corruption. And thus the [proposed] order between potencies and their acts is backwards. Similarly, since agents are able to fail, thus they are able to be impeded. Nevertheless, that they are impeded is prior by nature to their failure. And thus it is best said in the text, regarding the actual failure, that it is always from some hindering cause. Nor is this the Stoic error, but [that error was] that the potency for failure is due to the potency to being impeded, as is clear from Boethius in On Interpretation Book I [see Major Commentary, III.10, n. 10].
9. Now, to the second doubt, however much it can be easily said—and well—that either proposition is brought forward by opponents, so that an integral argument be made, that the propositions brought forward be of such a sort both in themselves and as regards this purpose, it is expedient when treating of this to examine both propositions. Still, in view of more profound considerations, the depth of this discussion will appear from what follows.
[II.B: Against proposition (1), the claim that everything that happens de novo has a cause]
10. However, the examination of proposition (1) consists, first, in its destruction as a universal claim. This is by distinguishing between what is and comes to be per se and what per accidens, and because a per se being has a cause, while a being per accidens does not. The proof of this is that what is not truly a being does not truly have a cause, and a being per accidens is such a being. This is proved as follows: because it is not truly one, as is clear. Second, [the examination] consists in the application to what was proposed, distinguishing, in the production of the effect which is called per accidens, the causes themselves, of which one hinders the other, from their concourse. It is said that, granted the causes themselves cause necessarily, nevertheless their concourse is per accidens. And consequently the effect arising from that concourse lacks a cause from which it follows necessarily. Each is supported by a known example from nature.
[II.B.i: Two doubts about the above denial of proposition (1) that everything that happens has a cause]
11. However, there are many doubts here, and would that God illuminate them [for us]. Concerning the examination of proposition (1), namely, everything that happens has a cause, a twofold doubt arises—one simply speaking, and one ad hominem.
[The first doubt], simply speaking, is as follows: Just as an effect that is, as it were, simple—such as white or hot—has in the heavenly body some per se cause to which it is reduced as to its proximate cause, so also a concourse of proximate causes is caused from the concourse of those heavenly causes. Take the example in the text: that there is something burnable on the surface of the earth is due, eventually, to heavenly cause A; likewise, that a burning body come to be up above and fall downwards is due to heavenly cause B; therefore, the concourse of the burnable body with the burning body is due to the concourse of A and B. Yet more: the concourse of A and B is per se and not per accidens, for all things there [in the heavens] are per se. Therefore the concourse of those inferior things has a per se cause, according to being, although to us it is per accidens, since the essential nature of its connection is hidden [quia latet suae connexionis perseitas]. And, for a long time, this argument seems to have held me captive [haec ratio multo tempore me vinctum teniusse videtur].
Now, the second doubt ad hominem is this: When examining this in Metaphysics Book VI [lect. 3], St. Thomas seems to prefer the complete opposite to what he says here. For here [in this text], all is resolved in this, that the concourse does not have a cause; yet there [in the other text], he preserves [the idea] that the concourse is able to have a cause of a higher order, namely, that the concourse of these inferior things is able to have a celestial cause. And he gives an example of things coming into bloom. Again, here [in this text] he says that the impediment of the cause is reduced to some cause; yet there [in the other text], all is resolved in this, that the impediment does not have a celestial cause. And this makes the whole issue unclear.
[II.B.ii: Cajetan’s solution of the doubts]
[(a) Three preliminaries]
12. To manifest these difficulties, three [preliminaries], with the help of God, are to be noted, which are [as follows]:
(1´) the proportion of the mover to the mobile
(2´) the reduction of effects to superior causes
(3´) the proportion of heavenly bodies to those bodies here below.
Concerning (1´), it is evident that, since the mover as such presupposes and does not make the mobile, that any action whatsoever, so as to come forth from the agent, if it be sufficient and in the best circumstances, is not impeded. Nevertheless, so that it is received in the patient, it is necessary that [the action] be modified according to the nature and mode and dispositions of the mobile, as is clear inductively. For this reason, it happens that the effect intended by the cause does not come forth, due to an impediment not of the agent cause but of the matter.
Concerning (2´), it is likewise plain that the effect of two subordinate causes (belonging to the same genus) is reduced to a superior cause through some middle cause, as it clear in syllogisms. For any contingent conclusion whatsoever is reduced to a contingent premise and another necessary one; yet its contingency is not reduced to a necessary premise by way of another contingent one, as if the contingency of the conclusion is from the contingency of the premise, and the contingency of the premise is from another necessary premise. Rather, it is enough that the conclusion itself and its contingency be reduced to a necessary premise as modified by the contingent premise. And because that very [premise] modified to the contingent is itself contingent—granted that in itself it is necessary—thus the contingent conclusion follows, not a necessary one. And if the contingent premise itself is to be reduced to the necessary, it is not reduced as a whole to it. Rather, it is to be resolved to that which belongs to [that premise], from which it has [its] contingency, and in that which partakes of the superior, due to which it partakes in being or causing.
Concerning (3´), however, two proportions are apparent, namely the mover to the mobile, and the principal agent to the instrumental one (or the superior to the inferior). For it is well known that the heavens act upon these [inferior] bodies, and that the heavens with these bodies causally bring something about, for the sun and man generate man [Aristotle, Physics II.2, n. 11; St .Thomas, lect. 4]. But it is to be diligently noted that, although these two proportions are of diverse genera (because one regards the genus of the efficient cause, the other the genus of the material cause), and again, the one is between the heavens and these bodies absolutely, while the other is between the heavens and this body in an order to a third (namely the patient and the effect produced by the heavens and this proximate agent), nevertheless they are bound by such a connection and order that the prior modifies the posterior. The connection is that the inferior agent never works with the heavens unless it is simultaneously affected by the heavens, because they do not cause motion unless moved. The order is that it is naturally prior to the inferior bodies to be affected and moved by the heavens, than [it is] to work with them, as is clear on the same basis. However, there is modification because every being or activity whatsoever is modified according to the dispositions of what receives being or of what elicits the action. For every act belongs to that of which it is the act through the mode of that thing, on account of which it must come to be in the patient and disposed thing, as is said in On the Soul Book II [ch. 2, n. 12; St. Thomas, lect. 4]. But the action of the inferior bodies cooperating with the heavens follows upon their being affected by the heavens. Therefore, the being active, or action, is modified according to the being affected. For this reason, if passion is not totally subjected to the heavenly bodies, neither is action totally reduced to them.
[(b) Three points]
[1st: Effects not reducible to heavenly causes]
13. These things accordingly presupposed, I say three things. The first is that, granted every effect of an inferior nature with each of its natural conditions depends upon the heavens by reason of the first motion (as upon a most common cause, without which nothing would come to be), nevertheless, not every condition of a natural effect is reducible to some purely heavenly cause, whether mediately or immediately. The proof of this: Because the condition of the effect arising from a material impediment is not reduced to a mover, or active [agent] on it, as is clear; but there are many conditions in effects here below that arise from the disposition of matter, that is of inferior bodies, which are matter and patients with respect to the heavens. Therefore, etc.
And if it is said with Avicenna that those material dispositions are caused by some heavenly body, and thus the same result follows—to exclude this, fashion the argument not about some part of the heavens, but of the whole [of it] at once, as implicitly assumed above: But with respect to the whole heaven, the inferior bodies are matter and patients; therefore, they have [their own] proper conditions presupposed to the whole heaven in this, as the active is in things here below. Consequently, the conditions of the effects following upon the conditions of these bodies as matter are not resolved to the actions of the heavenly bodies, but to the conditions of inferior bodies.
And if you add to this foundation that the proper conditions of these inferior bodies are able to fail, both from being (whether substantial or accidental) and consequently from acting and suffering, that they have a variable and ever-mutable being, contraries, etc., the consequence is that the heavenly influences upon these bodies are modified according to their conditions. And due to this, the effect need not imitate the heavenly causes alone, but must be such as follows upon how the influence of the heavens is received and modified in such matter. And if to these one adds that the coaction of these inferior bodies is modified according to their proper conditions and their undergoings due to the heavens, the consequence will be that the action of these [inferior bodies], although subordinate to the action of the heavens, nevertheless does not reduce according to all of their conditions to some pure heavenly cause, but modified corporeally as a patient, etc.
14. And because it is manifestly clear that to be able to fail for the lesser part (which is the root of chance and fortune and every contingency in natural things) follows upon being able not to be, and, to say it in a word, it follows upon the imperfection proper to inferior bodies, the consequence is that contingent things as such are not reduced to some pure heavenly cause, either immediately or mediately—[not immediately], since something such comes to be by the heavenly bodies concurring purely passively with inferior bodies, [nor mediately], since something contingent comes to be by the heavens and an inferior agent, but both contingent things are resolved to the condition of inferior bodies. Yet [to put it] differently, because the heavens alone concur actively, the contingent effect is reduced to the conditions of these bodies as to a material condition. Now, since these agents cooperate, the contingent effect is reduced to the condition of these bodies as to an agent condition, which nevertheless is compared to the heavens as something patient, as said above [see n. 13].
Thus, the divine genius of Aristotle, in both On Interpretation [ch. 9, n. 10; St. Thomas lect. 14], and in Metaphysics Book VI [St. Thomas, lect. 3; also, V, ch. 3], and in Physics Book II [ch. 6, n. 9; St. Thomas lect. 10], always resolves the contingency of natural things to the condition of inferior bodies because, of course, they are able to fail. But as to the genus of reduction, in Metaphysics Book VI he leaves it under doubt as to whether [it reduces] to the material cause or the agent cause; while in Physics Book II he reduces it to the agent cause, chance and fortune; and yet in On Interpretation Book I he reduces it to matter, or passive potency. And all of these are true, if what is said is considered. You can consider this most fundamentally in Summa contra Gentiles III.86.
15. That this argument destroys the basis of Avicenna’s reasoning, is founding in this, that inferior bodies are presupposed matter and patients to the whole action of the heavens. Besides the proof brought forward (namely, [above, n. 13], that every agent [that acts] through motion or change presupposes the matter upon which it acts, but the whole heaven [is such an agent], [therefore] etc.), I now bring forward against the reckless an argument which not even Avicenna himself will be able to deny, from On the Heavens Book II (text 17ff [ch. 3; St. Thomas, lect. 4]). The argument goes like this: The elements regard the substantial integrity of the universe, therefore they are presupposed to the action of the heavens. The antecedent is clear there [in Aristotle’s text], where it is shown that the earth naturally precedes even the first motion of the heavens and, since the earth is the lowest, thus ever other element naturally precedes. Nor is it a difficulty that in the Meteorology Book I [ch. 3, n. 13; St. Thomas, lect. 4] it is declared that the diverse forms of the elements is according to the drawing closer to or receding from the motion of the heavens, because there it concerns not diverse form as such (since this was established in On the Heavens Book II [ibid.; see also On Gen., II.4, n. 2; suppl. St. Thomas, lect. 4]), but such a diversity, namely that the highest is the most hot, etc. And again, such a diversity of form follows upon the condition of matter and not only [their] closeness or distance, as is clear.
[2nd: The division of impediments]
16. Now, the second point, as is already clear from what has been said, is that an impediment is twofold: the one is active, the other material. For the active [impediment] is what hinders the action on the part of the agent, or as issues from the agent; however, the material [impediment is] what hinders the action as it is received in what suffers. And again, material [impediments] come about in two ways. In one way, due to the action of another agent: as when the wetness of wood hinders burning, for although it is a material impediment, it is nonetheless the effect of rain as a cause, which soaks the wood. In another way, due to the very condition of the matter: as the coldness of water hinders being heated, and yet the coldness is not some other cause beyond the very nature of the water, which occurs in materials able to be heated. From this the first thing that we said is made clearer yet, and that the condition of inferior effects following a material impediment obtains from the condition of the matter itself, not due to the action of the agent or being caused by the heavens. And this is what St. Thomas means in Metaphysics Book VI [see above, n. 11], where he reduces contingency to a material impediment.
Nor is the opposite said here [in Article 6 of this Question], when he says that “that such causes do fail in the minority of cases is due to some hindering cause.” For here the discussion concerns the defect of active causes on the art of the action (as it is from the agent), and consequently from an active impediment, as the series offered in the text shows. Moreover, given that the discussion concerns every mode of impediment, he does not say that the hindering cause is an active cause, but says absolutely that it is “some hindering cause.” Whence not only active [causes are meant], but it can also be a material [cause], as is expressly said in the text in response to the second [objection].
And if one insists against this gloss that the text goes about things badly by the comparison of the hindering cause with the cause of failing for the lesser part: “consequently the above-mentioned difficulty seems not to be avoided, since the cause in question is hindered of necessity” [see above, n. 3]—I respond: it is both sufficient and according to the mind of St. Thomas that the argument advanced is not made according to the truth of the matter, but its appearance only. This is clear in two ways: First, because he says “the above-mentioned difficulty seems not to be avoided.” Second, because in this same article he refutes this argument in the text “Now it is manifest that a cause which hinders the action of a cause …,” where he expressly shows that from the antecedent an agent failing for the lesser part on account of some hindering cause it does not follow that therefore, those which come about for the lesser part, come about necessarily, because the concourse for the impediment is per accidens, given that the hindering cause itself is per se the cause of that thing which it hinders.
17. Yet this is not intellectually satisfying, since according to this response, that consequence is not brought forward as true, but as [only] apparent and [to merely agitate]. If this is so, when the examination of that proposition—positing the cause posits the effect—and being able to refute it properly, namely from the nature of the material impediment obtaining from the condition of matter, why is it dismissed and refuted on extraneous [grounds], namely, from an examination of the other proposition, everything which is, has a cause, because the concourse has no cause?
The answer is that the refutation on the part of matter either is wholly the same as the refutation on the part of the concourse (a´), or it includes it and is distinguished from it as inferior from superior, with the greatest difficulty (b´). For “impediment” means two things, namely the thing which hinders, and the relation to something else due to which it is called an impediment.
(a´) Concerning the active impediment, given that as it is a thing it has a per se cause, but insofar as it hinders it is not necessarily so, because to hinder belongs to the concourse, which is able to be per accidens. Moreover, concerning the material impediment the same holds, namely, that insofar as it is a thing it has some necessary cause (whether that be some agent or it be some material condition), [yet] it must be said that insofar as it is an impediment it is per accidens. And this is “to come to a concourse”—which is to say nothing other than that the concourse of such an agent with such matter here does not have a cause. And thus the impediment on the part of matter and this concourse are wholly the same.
(b´) However, if the material impediment—even insofar as it is a thing—is taken in the particular not to have some cause which follows necessarily, then due to the material impediment something comes about per accidens in two ways: on the part of the concourse, and on the part of the things [composing the] concourse. And thus the material impediment includes the impediment of the concourse and more—thus, it is distinguished as the less common from the more common.
Whence, since this is very difficult and unclear, requiring a lengthy discussion, and [since] the present work (as was said in the prooemium) is for beginners being instructed in theology, it had to be refuted more briefly and clearly. Therefore, on account of the clarity and brevity of this teaching, he proceeds to refute the argument as to its second proposition.
18. Nor is such a refutation from extraneous [grounds]. No indeed: it is from proper [grounds] of the impediment insofar as it is an impediment, since, as is clear from the aforesaid [see n. 17], the concourse belongs to the impediment as such. Nay more, speaking in general, as the text does, to descend to the impediment insofar as it is material, and thus to refute that consequence, would be rather to turn away from the proper [grounds]. And this can also be assigned to the other argument of this passage, namely that it might stand on the proper [grounds] of an impediment as such.
One could even understand the meaning of the text in another way, that St. Thomas does not speak absolutely by going to the other proposition, but with a limitation, namely according to these two [propositions], as if to say: If we are unwilling to go beyond these two claims given by the ancients, and refuted in common by Aristotle, it is necessary to go to the other [consideration]. And the reason is that having examined the instance against the first proposition (namely, positing the cause posits the effect), he does not formally exclude it, since the instance does not take up the whole cause of the effect in the lesser part. And yet the cause of the effect in the lesser part is not that alone, but that with the hindering cause, since it never fails unless impeded. Whence, it is necessary to give an instance that, both posited simultaneously, the effect does not follow. And therefore one must go to the concourse, which lacks a cause.
Nevertheless, as will be clear below [see n. 22], virtually the instance given suffices to falsify that [claim], because from the nature of the possible found in failing causes, the concourse of that which another is per accidens.
[3rd: The nature of the concourse itself]
19. Third, it is to be said that the concourse, just like the impediment, is manifold: namely, of active things, or of an active and a passive thign with their conditions, etc. Nor does this go back to the proposed, about which concourse we are speaking. Whence in the text of the body of the article, an example is given of the concourse of an agent cause and a material cause. Yet in the response to the third [objection], he speaks of the concourse of active agents also.
Accordingly, it must be true generally that, if two things concur, and whatsoever belongs to them separately has a whole necessary series of causes, and the supreme causes of each order concur per se—thus, it is necessary that the concourse of all the intermediate and ultimate effects be caused necessarily by the concourse of the superme causes, for I cannot understand the opposite [case]. But if these two conditions posited in the antecedent do not obtain (namely, that the supreme causes do not concur per se, or the whole series of some order is not necessary), it is not necessary that the concourse of the proximate causes or [their] effects have a cause from which it follows of necessity.
From the aforesaid, however, it is now clear that, when something which we call per accidens comes to be, that thereupon two concur together (namely, as in the example in the text, burning and this matter, such as grain, being consumed), and that while one of these is reduced to some heavenly body, the other is sometimes reduced to the condition of inferior bodies just as if to a first cause. Thus, since the concourse of the heavens and this inferior body, which are supreme causes of the effects of the concurrences, are not per se, but can be per accidens, it follows that the concource of these effects does not always have a per se cause. Similarly, although sometimes either effect is reduced to the heavenly bodies as supreme [causes], nonetheless, because the whole series of singular causes is not necessary separately, because there arises a resolution of this effect to the supreme heavenly cause, the middle cause [is] not necessary, but able to fail, or possible. This does not follow: Therefore, the concourse of effects hsa a per se or necessary cause, [namely,] the concourse of the supreme heavenly causes. And rightly so, because the concourse of those stars, although in itself it is per se and necessary, nevertheless as connected to these effects it is contingent, because it is connected by way of bodies able to fail. In the same way, too, granted that the single heavenly agents are in thelseves necessary, nevertheless as related to these inferior bodies they are agents for the most part, and sometimes fall short, because [their influences] are limited in these bodies able to fail.
[(c) The doubts raised in n. 11 are answered]
20. From these, the respone to the objections is clear [see n. 11]. To the doubt simply speaking, it has already been said that the concourse is not due to a concourse as a necessary cause, and for what reason, etc.
To the second doubt, the ad hominem one, I reply first to the various points separately, saying that there is no intrinsic contradiction. This is because there [in that text in the Metaphysics], he affirms in the particular that the concourse has a cause, while here [in this text] he confutes the universal claim that every [such] concourse has a per se cause. Likewise, in the former text he concedes the particular negative claim, namely, that material impediments do not have a heavenly causes, where there are two particular things: first, the impediment, second, the cause. In this latter text, however, he assumes that every impediment has a cause, but not a heavenly or effective, nor necessary, one, but absolutely that they have a cause. This is clearly not incompatible with the former.
Nevertheless, know in this case that the account of the contingency of natural things can be assigned in two ways: in one way, on the part of the complement, and in another way, on the part of the root. Now, the root of such contingency is the nature of potency found in natural things, by which they are both able to fall short for the lesser part and are in potency to contradictories, as stated in On Interpretation Book I [St. Thomas, lect. 14]. Yet the complement of contingency is the accidental concourse of causes, whether active and passive, or of active ones among themselves, etc. It is on this account that the divine Thomas is not saying opposing things, but assigns each of these in the different texts: accordingly, in Metaphysics Book VI he mentions the root [of contingency], while here and in On Interpretation Book I and in [the aforementioned text from] the Summa contra Gentiles, he touches on the complement [of contingency].
[III. Answering a doubt about the response to the third objection]
21. A doubt occurs in regard to the response to the third objection: Whether every natural thing (taking “thing” here as distinguished from a concourse) has a cause due to which is comes to be necessarily. For it seems that the text of the article concedes this twice. First, in the response where he states that the effect of a cause hindering a natural cause from its effect reduces to some heavenly cause. And if such a thing has a necessary cause, no thing will be without a necessary cause, because such a thing comes to be outside of what is always and for the most part. [Second,] also in the body of the article, he says that, because a cause does not fail for the lesser part unless through some hindering cause, therefore the impediment itself seems to be necessary. And this is not to deny the antecedent, but so as to refute the consequence [regarding] the concourse.
To the opposite, however, is the argument brought forward above, namely, that when the whole series of causes of some effect is not necessary, the effect does not follow necessarily. But the effect for the lesser part does not have an entirely necessary series of its own causes, because the heavenly causes reach it modified in the nature of the possible as such, because it fails for the lesser part. Therefore, etc.
22. To this, a brief response: There are three genera of things which come to be. For some come to be always, and the question is not about such things. Others come to be for the most part, and concerning them it is also clear that they come about necessarily, not simply speaking, but by physical necessity. Yet other things come to be outside of what is always or for the most part, and these do not come to be from one single cause, but from many—as is said in the text—namely, by the cause that fails for the lesser part and by the other cause making it to fall short in those cases. As a result, such an effect never happens unless there is a concourse of many causes (ignoring the mode of the genera of causes). Whence, if both causes are considered in themselves, there will not be some per accidens being. And if both concur on the part of those things having natural necessity, then also something per accidens will never happen. But if both or one concur on the part of things that have or a nature having contingency [possibilitatis], the concourse is already contingent, and thus whatsoever comes to be from such causes and [their] concourse as such will come to be contingently.
As is already clear, natural causes have something of the nature of necessity and something of the nature of the possible. This is clear from their operations, for their works are for the most part and frequently, and this is the nature of the necessary, as is clear. And [their works] are [also] outside what is always and frequently, and this is the nature of possibility (whence wholly necessary causes do not have either sort of work, but always act in the same way). Therefore, to causes and things having the nature of the possible due to that part which falls short for the lesser part, if there is a concourse with other causes dueto such a part, there the concourse will be contingent. And if [it is with] other causes that are in themselves necessary, nevertheless as a conjunct possible as such, declines to the contingent, and contingently attains to that effect which comes to be due to the concourse of both.
23. From this is clear, first, the response to the question [see n. 21], that not every thing has a necessary cause, namely those which come to be beyond what is always and frequently. Second, it is clear how the concourse is a complement of contingency and a root of possibility [see n. 20].
Third, this clarifies the reason for the words of St. Thomas both here and elsewhere. Namely, that he intends not that every thing [has a necessary cause], nor that things which come to be for the lesser part [ar such], but that the effect of those two concurrences of causes—not insofar as they are concurrent but insfoar as they are taken of themselves separately—are reduced to some necessary causes. This is since no mixed body arises from the necessary to the possible as it is possible, because every such mixed body comes to be by a concourse of many causes. But a thing which si the effect of a hindering cause and an impeded thing, as such does not have a cause. And he has this meaning in this text, and in the body of the article, and in the other places, as is clear.
Although one could say that the text does not universally affirm even that the effect of causes separately are reduced to necessary causes, the reply would be that, such would be the case, as is clear from the “granted” [used by St. Thomas]. And again, he is speaking only about an effect of causes which are subordinated to the heavenly bodies, and not about the conditions of matter presupposed to the entire action of the heavens. Also, in the body of the article, as is already clear, nothing is maintained affirmatively except that no cause actually falls short for the lesser part unless this is due to some hindering cause. Yet the text does not say whether the effect of that hindering cause taken of itself comes about necessarily or not. Nor does it do to argue negatively, that he does not refute this, therefore, etc. For it has already been said [see n. 17] why he does not examine this regarding the nature of the possible and the necessary.