Disputationes metaphysicae

1. It remains, then, to speak of the third point, which is chiefly intended in this section, namely, of several causes of the same genus and species or order in that genus. And, in order that we may come at once to the point of difficulty, the intrinsic causes, material and formal, are to be excluded, for in them this question has no place, as is evident a fortiori from what was said in the second point of the preceding section. The question has place, then, in efficients, and the reason is almost the same of ends, as we shall add at the end; and we shall show that the same must be said of any cause inasmuch as it is extrinsic. Again, the difficulty is about causes total in their order; for of partial ones there is no difficulty, because it is established that many natural effects are from several partial proximate efficients, as the same son from father and mother, supposing that the mother concurs effectively, and the same light or heat from many lamps or fires, and so of others. And the reason is that, when the causes are only partial, from all there arises only one total and sufficient cause; therefore nothing prevents several causes from concurring in that way, because those are not so much several causes as several parts of one cause. For neither is it necessary that the total cause be so one that it be either simple or per se and properly composed through real union of the partial causes, but it suffices that it coalesce from several helping one another to act, and sufficiently conjoined or brought near, so that they can inflow in their partial way. In this part, then, there is no difficulty.

2. But about total causes a twofold question still turns. One is whether the same effect can proceed at once and conjointly from several causes. The other is whether at least successively or dividedly the same effect can be made by various causes, that is, whether that which is made by one would be made the same in number by another, if it were applied to the same matter at the same time. We shall speak first of the former question, and then of the latter.

The first opinion, denying wholly that this is possible

3. There is, then, a first opinion teaching that it is so impossible that several causes concur at once in that way to the same effect that it implies a contradiction, and therefore cannot be done even by absolute power. So thinks Scotus, In III, dist. 1, q. 2, and In II, dist. 20, q. 2. And many Thomists think the same, who, while they say this is impossible, add a proof inferring implication of contradiction; so Cajetan, III, q. 67, a. 6, near the end; Soncinas, V Metaph., q. 6; and Capreolus, In II, dist. 20, q. unica, a. 3, to the arguments of Scotus against the 3rd conclusion, and In III, dist. 1, q. 1, a. 3, to the arguments of Scotus against the 2nd conclusion; and Ferrariensis, III Cont. Gent., c. 68; and Javellus, V Metaph., q. 7. And this opinion in this sense is commonly attributed to St. Thomas, because sometimes he absolutely says that this is impossible, as in I, q. 52, a. 3, and III, q. 82, a. 2, ad 2, and In I, dist. 37, q. 3, a. 3, and V Metaph., c. 2; and Marsilius thinks the same, I De Generat., q. 8. And I do not doubt that this was the opinion of those philosophers who thought that to be simply impossible which cannot be done through natural causes, of which we shall speak at once.

4. The foundation of the proposed opinion.—But this opinion is founded, first, on this, that it is against the notion of a total cause that it have the partnership of another in the same order, for the total cause is that which acts with the whole power necessary in that order for such effect; therefore it is repugnant to the total cause as such to have the partnership of another like cause in the effecting of the same effect. The consequence is evident, because by the very fact that it has another cause concurring, it no longer applies the whole necessary power. Or certainly, if it applies the whole power, and nevertheless the other too exhibits its own, more power is actually applied to that effect; therefore a greater effect too will proceed, and consequently it will be made by them as by partial causes and by neither as total. For it seems to involve manifest repugnance that a more powerful cause should actually operate according to its whole power, and yet operate no more than if a less powerful cause alone effected. And it is confirmed, secondly, in this way, for if one cause effects the effect as total cause, then either the other does nothing, and so it is falsely called a cause; or it does what has been done, and this is impossible, because to act is to educe from non-being to being, for, on the testimony of Aristotle, every action takes place between these termini; but that which has been done by one cause is already outside non-being; therefore it cannot be made by another. Thirdly, it confirms this very thing, because otherwise one total cause could not only at the same time and in the same instant, but also at a later time, produce a thing already produced by another, which is against the notion of production, as we have said. Hence further it would come about that the same thing could produce itself, because if it could not, most of all because for acting it is supposed to be; but even if the thing already is, it can be produced again by another cause; therefore also by itself.

5. Fourthly, it is impossible that the same action be from two total causes; therefore also the same effect. The consequence is evident, both by parity of reasoning, and also because one effect cannot be made except by one action. But the antecedent is proved, because action depends wholly essentially on the agent; one and the same action, then, cannot depend at once on several agents and on each as total. Hence there is the fifth and common reason, because otherwise it follows that such effect depends and does not depend essentially on those causes, which is a contradiction. The sequel is evident, for that it depends is asserted in this very thing, that each of them is said to be a per se and total cause, for a per se cause is that on which the effect per se depends, and a total one that on which it totally depends. But that it does not depend is proved, for if this one is taken away, nevertheless the effect will remain in reality from the influx of the other, since it is said to be a total cause; therefore it does not depend on this one. Again, if this one remains, although the other is destroyed, the effect will remain; therefore it also does not depend on the other; therefore it depends on neither. But if it is said to depend on either confusedly or disjunctively, then in fact neither of them determinately and per se taken is a total cause, because on neither of them determinately taken does the effect depend. Sixthly and finally I argue that, if the concurrence of such causes is not absolutely repugnant, neither will it be naturally repugnant, which this opinion supposes to be wholly false.

The second opinion, affirming it even naturally

6. The second opinion, extremely contrary, can be that it neither implies contradiction nor, per se speaking, is repugnant from the nature of the thing that two total causes of the same order effect the same effect at once. I say per se speaking, because perhaps on the part of the antecedent conditions necessary for acting two causes cannot according to the order of nature be so applied that they effect the same effect at once and totally; yet per se and by virtue of causality, even natural, it is not repugnant. For if two agents are so applied to some patient as is necessary in order that each can totally effect some effect, both too will effect it at once and in the same way. And this opinion, as it seems, Cajetan holds, I, q. 52, a. 3, where, although he interprets St. Thomas, saying that one effect cannot be from two total causes, as to be understood not of logical but of natural power, yet in the discourse he so explains it that he places that natural repugnance only in the application of the causes; but from the hypothesis that the causes are applied, he openly teaches that the effect will naturally emanate from them at once as from total causes.

7. The foundation of the proposed opinion.—But this opinion can be founded on the last argument made for the prior opinion, taking the contrary principle in this way. It does not imply contradiction that there be two total causes of one effect; therefore, if two fires, for example, were equally applied to the same matter disposed in the same way, they would naturally act as much as they could; therefore they would act one and the same effect, because we suppose the same matter is not at once capable of several; but then each would act as total cause, because we suppose each has a sufficient principle for effecting that whole effect, and each would naturally act as much as it could; therefore each would produce the whole effect as its total cause, since from elsewhere no repugnance is adjoined. And it is confirmed, for then either each fire would act or neither, because there is no greater reason of one than of the other; but it cannot be said that neither would act, because there is nothing which impedes them; for since they are alike in power, one does not impede the other; but we suppose that no other impediment intervenes; therefore each acts, and with its whole power, and therefore as total cause.

8. And hence it can further be concluded, not only in the said sense, but absolutely, that it can naturally happen that the same effect proceeds from two total causes, because that supposition, namely that two sufficient agents are applied at once and equally to the same effect, there is no reason why it should naturally be repugnant. For Cajetan adduces no other reason except that nature abhors superfluity. But this is not enough, first, because, although nature abhors superfluity, yet not abundance, nor is that always to be called superfluous which is not simply necessary. It would indeed be superfluous to demand two causes where one suffices; yet that nature was so provident as to confer on several causes sufficient power for the same effect is to be called not superfluous but rather liberal. But that those two causes concur at once, although it was not per se primo intended by nature, can yet be permitted and contingent, since it has nothing repugnant to the natures of things. Secondly, nature abhors a monstrous effect more than superfluity, and yet sometimes it does not refuse it, if the order and concurrence of natural causes produces it; why, then, cannot the same be said of the multitude of total causes? Thirdly, although nature so abhors superfluity, yet a free cause does not always abhor it; therefore two angels can at their will apply their whole power to moving a stone, and then each will move as total cause. The same can be said of two men, if each has the whole power sufficient for carrying a stone, and both at once at their choice apply it wholly. And this opinion is commonly attributed to Ockham and Adam, whom Capreolus, In III, dist. 1, reports from In I, dist. 1, dub. 4; but there I find nothing and the allegation is ambiguous, because there is no dub. 4 there, but various questions, and neither in the 4th nor in the others do they say anything.

Approval of the third opinion and resolution of the question

9. Between these opinions I think a middle way is to be held: it must be said, first, that it does not imply contradiction that the same effect proceed from two total causes. As to this part the opinion of Cajetan pleases, which he also insinuates in III, c. 3, a. 6. Nor can it be better proved than by answering the prior arguments; for if there is nothing which proves contradiction, there will be no reason why it should be believed or asserted. But conversely, since God can do everything in which repugnance is not shown, He will also be able to make two total causes effect the same effect. And it is declared briefly in this way, for God can, this sun existing in this hemisphere, create another equally perfect and equally applied to illuminating. Again, He could through another sun effect in the air the same light in number which this present sun now makes, dividedly, or without this sun concurring or assisting; for what repugnance is there that God make through one cause what He can make through another? Indeed in the following point I shall show that this can even be done naturally. These two luminous bodies, then, existing at once and applied, God can supply to each the whole concurrence necessary for producing the same light and bring it about that each of them produces it by its own proper action, total and independent of the other, which is to be properly a total cause; for no repugnance intervenes in this, as will easily be evident from the solutions of the arguments.

10. What is of the notion of total cause.—To the first, the assumption is denied, namely, that it is against the notion of total cause that it have another like and equally inflowing into the same effect. For, although, in order that a cause be total, it is necessary that it actually operate with the whole power necessary in that order for the effect, yet this is not taken away or impeded from the fact that another cause acts with like power and action, but each will exercise its whole force and action about that effect. But when it is inferred that then greater power is actually applied and consequently the effect increases, a distinction must be used about greater power, either intensive or extensive. And of the intensive the assumption is to be denied, because several agents equal in intensive power, per se speaking, do not compose one of more intense power or efficacy, but that multitude can only contribute to a more intense effect when neither agent could act according to its whole intensity on account of some impediment, as was treated at length in the foregoing. But in the present case we suppose that the single agents act according to the whole intensity possible to them, or certainly that God does not supply concurrence for a more intense effect, but up to a certain grade which can be made by each, and gives to each the whole necessary concurrence. The acting power as such, then, does not increase intensively, and therefore it is not necessary that the effect increase intensively. Yet that power can be called greater extensively, which is not so much to be greater as to be several powers; yet it does not necessarily follow from this that the effects too be several, because at least from the direction of the first agent the influx of each secondary cause can be determined to the same effect, since there is no repugnance in this by virtue of the multitude or plurality of acting powers; for as several ways tend to the same terminus, so several acting powers too can tend.

11. The mode which several causes of the same order concurring to the same effect would observe.—To the second and third it is answered that, when two total causes so acted the same effect, one indeed would act the whole and by a total action, and the other would not act nothing, but would act that same whole effect by another total action. But those causes can be understood to effect in two ways: first, so that they begin to effect wholly at once and in the same instant, and so neither, properly speaking, acts what has been done, because neither acts before the other, either in time or in nature. For we suppose that they are equal and not subordinated among themselves, but behaving merely concomitantly; neither, then, supposes the effect of the other as already made prior either in time or in nature; neither, then, acts what has been done, but each acts the same which the other acts, educing it from non-being to being, and this was enough for our conclusion. But in another way it can be understood that one of these causes has produced that effect prior in time, and afterwards the other begins to effect the same by a total action. And indeed, if the prior has already ceased from its action, there is no difficulty nor is it the case of which we dispute, because those two causes do not concur at once to the same effect, but successively, the prior as effecting and the posterior as conserving; which too I shall say below can happen naturally. It is necessary, then, to posit that, the prior agent continuing in its total action by way of conservation, another begins to effect the same effect, and this too we say is not repugnant. For to effect extends more widely than to produce anew, because to conserve too is to effect. That agent, then, could anew effect the same effect by conserving it; which action, although it could have been production, yet then in that case cannot receive that denomination, because production as such connotes on the part of the effect a certain negation of prior existence. Although, then, it is repugnant to do what has been done, that is, to produce anew that which pre-exists, yet it is not repugnant to conserve what has been made. Nor yet does it stand in the way that it is conserved by another cause, because, just as in the beginning it could be made by two, so afterwards it can be conserved by two, although before it was produced by one only.

12. The same thing can supernaturally participate efficiency upon its own substance.—But what is further inferred in the third argument, that the same thing could have efficiency upon itself, is in my opinion no drawback, speaking of absolute power and of conservative efficiency, provided the thing is supposed already produced and conserved through another action; of which matter I have written more at length in tome III of the III Part, disp. XLIX, sect. 1, and disp. L, sect. 4, at the end, because that miracle is proper to that mystery, and therefore pertains to the theological disputation. But lest the present resolution seem necessarily connected with that opinion, it can be answered otherwise by denying the sequel, because in efficiency of itself there is a peculiar difficulty which is not in efficiency of another, even if the thing is at once made and conserved by another cause. Because the efficient cause seems necessarily to demand distinction in reality from the effect, and therefore no thing, inasmuch as it is active, includes itself under the object of its activity; and therefore perhaps it cannot happen that it have action upon itself according to its proper being; but two active powers can enclose under the object of their activity one and the same thing distinct from them, as we shall declare a little below. And from this side there can be greater repugnance in conservative efficiency of itself than of another thing, although it is not convincing; for, although that assumption is true of the object contained under natural power, yet not of every thing to the effecting of which a thing can be elevated through obediential potency; but of this elsewhere.

13. In the fourth reason it is asked whether the effect made by two total causes can or must be made by one or by two actions. And it must be said that it is necessary that it be made by two actions, as the argument made there rightly proves. Indeed I add that in this chiefly consists the difference between two causes of the same order, when they act as total causes or as partial; for if they act by one action, they cannot be total causes but only partial. Which I prove because a cause is not called total on account of power in first act, although that is an integral and total power, because by virtue of it it is not constituted a cause in act, but in potency; but here we are not treating of the total cause in potency, but in act. But a cause in act is constituted through actual influx, which is nothing else than the action itself; therefore, in order that a cause be total, it must inflow into the effect by a total action proper to itself in its genus; therefore, whenever the action is as it were divided between two causes of the same order, it is from neither of them totally or as from a total cause, and so each will be only a partial cause, with partiality on the part of the cause, as they say.

14. That a single action emanate from several total agents not subordinated implies contradiction.—You will say: by this reason it would also be proved that the first and the second cause are partial while they inflow into the same effect. It is answered that many so speak, as we said above, considering not the genus of causality but causality simply; but the sequel is better denied; for the reason is far diverse, for between the first and the second cause there is subordination and essential dependence, and consequently a diverse order of causes; and therefore each can be total in its order, even if it inflows with the other through the same action. But when two causes are of the same order, if they concur only concomitantly and inflow through the same action, they can be called total neither simply nor in that genus; they will be, then, partial. If, therefore, causes of this kind are to be total, they must inflow into the same effect by diverse actions; and it is repugnant that one and the same action be from two causes of the same order as from total causes, which also the fifth argument made above convinces, as will be established from its solution. Yet I deny that the reason is equal of the effect or terminus of the action, for the effect flows from the cause by means of action, and the same effect in number can be made through various actions, as we declared above in treating of the causality of the efficient cause; since, therefore, various actions can proceed from diverse agents, the same effect in number too can proceed through several distinct and total actions from diverse causes of the same order, and this very thing is to proceed from them as from total causes. But action does not proceed from the cause through another action, but by itself, and therefore one action cannot proceed except from one agent or from several by way of one; and therefore it cannot be at once from many causes as total in the same order, which will be declared more in the following solution.

15. To the fifth argument, then, it is answered by denying the sequel and that contradiction, whose affirmative part we admit, namely, that that effect depends on those causes and on each of them. But when it is proved that it does not depend, because, any of those causes being taken away, the same whole effect remains, it is answered by denying the consequence. For there is an equivocation in that word to depend, for, in order that one thing depend on another, it is not necessary that, that being taken away, this too be removed from the midst, but it is enough that it receive being from it, even if, that not giving being, it can retain being as given by another. For so the light of this air truly depends now on this lamp, and nevertheless, this being extinguished, the same light could be conserved if at the same moment another luminous body were applied sufficient to conserve such light. When, therefore, a thing is said to depend on a cause because, it being taken away, it is taken away, it is understood of the cause which is unique, and because regularly and naturally the total cause is wont to be so, therefore dependence on it is wont to be declared in that way. Or certainly there is to be understood there a condition, namely, that, the cause on which the effect depends being taken away, the effect too is taken away, unless from elsewhere another cause comes to aid which can conserve the effect in being, as happens in the present case.

16. The agent being taken away, the dependence of the effect on it must be taken away.—But it rightly and necessarily follows that, the cause being taken away, some dependence of the effect on it is taken away, by reason of which the effect too would be taken away unless it were conserved by another cause. It is proved, for every effect, inasmuch as it is from a cause, depends on it; but it can depend only as long as the cause is, because nothing depends on that which is not, especially efficiently, as was shown in the foregoing; therefore, the cause being taken away from which the effect proceeded efficiently, it is necessary that some dependence of such effect on such cause be taken away. But this dependence is not other than the action, as was also proved above; therefore it is also necessary that, the cause being taken away, some action of it about such effect be taken away; yet it is not necessary that the effect itself be taken away, because another sufficient cause holds it in being through another proper and total action. And hence is confirmed what we said before, that, although the effect is one, if the causes are several and total of the same order, it is necessary that the actions be several, because, the influx of one cause ceasing, its action is of necessity taken away, because the dependence on it is taken away, and nevertheless the action of the other cause can remain, because, since it is total and not subordinated to the other, it can conserve its action even if the other ceases from acting; therefore it is necessary that the actions be distinct.

The second assertion

17. Naturally the same effect cannot emanate totally from several non-subordinated agents.—The sixth argument demands that we pass judgement on the second opinion. I say, then, secondly, that it cannot happen naturally that the same effect be effected at once by several total causes. In this conclusion the philosophers almost agree, and Aristotle signified it, V Metaph., c. 2; for, saying that there can be several causes of the same effect, he adds but not in the same way, as St. Thomas and the other interpreters noted. Who all understand not only that this cannot be done naturally because the application of several agents per se sufficient cannot naturally be made; for this is both uncertain, as the arguments touch upon, and very remote and accidental; but they understand that, even the application of several agents of themselves sufficient being made (whether that application happens naturally or is posited to be made supernaturally), provided those agents are left to their nature, they will not effect the effect as total causes, but only as partial.

18. Various reasons of the second assertion.—But the reason of this conclusion so understood is not very easy. Some bring back the reason to another principle, namely, that no natural cause can naturally effect some effect the same in number which another can. From which principle one must philosophize thus. For in the first place it must be said that those two causes equally applied cannot produce one and the same effect at once, so that each makes it as total cause, because, by the very fact that it is contained in the power of one, it is not contained in the power of the other. And so it comes about that, if one of them by its sole power effects the effect which it contains, the other effects nothing; yet this will only happen when one is applied prior in time to the other; for then the posterior will effect nothing, because it already finds the capacity of the patient filled. But when both are applied at once, it cannot rationally be said that one effects the proper effect adequate to itself, and the other causes nothing, since there is no greater reason of one than of the other. Unless perhaps someone has recourse to the concurrence and will of the first cause and says that it is necessary that only one operate, and therefore God by His will gives concurrence to whom He wills, and therefore that one operates and not the other. But this, although it can be done by the first cause, yet does not seem philosophical nor consonant with the natures of things; for since each agent is equally powerful and equally prepared or brought near for acting, as we suppose, concurrence is not more due to one than to the other.

19. It must be said, then, that both together, as partial causes, produce one effect. For, although they cannot operate at once either several effects distinct in number alone, because we suppose the subject is not capable of them, or one and the same by way of total causes, because there is no effect which the same in number is contained in the power of each agent, yet it is not therefore necessary that only one of those agents effect its own proper effect; for both can concur by way of one to some effect contained in them taken together, which will necessarily be distinct from those effects which those agents singly and by themselves could totally produce. It is therefore more consonant with the natures of things that God supply to those agents concurrence for acting in this way, than that He give the whole to one and wholly deny it to the other. Those agents, then, will effect together in the said way; and so they will always act as partial causes and not as total, because that effect so proceeds from each of those causes that it could proceed from neither alone, and so it will also proceed by one single action, because it so depends on both those causes conjointly that it cannot be without either.

20. But this discourse, although it proceeds rightly from the principle posited, yet the principle itself is to me very uncertain, nor do I think it can be proved by any sufficient reason, as we shall declare in the following point. And therefore a more certain conclusion does not seem to be founded on a less certain thing; but it is more constant in philosophy that several total causes cannot conjointly effect the same effect than that they cannot dividedly. The conclusion, then, is better founded in this, that one effect in number cannot naturally be made at once except by a single action; but a single action cannot be from two total causes of the same order, as was proved above; therefore neither can one effect naturally be made by several total causes. The major is proved, first, because the unity of the action is in some way taken from the terminus; I say in some way, because relation to the agent is also necessary; yet, since unity of terminus is also necessary, at least from that head, for one terminus a single action is naturally demanded. Secondly, although the agents are several and otherwise could effect singly, yet they can also be conjoined for acting by way of one, and this mode of acting is more consonant with the unity of the terminus; therefore, naturally speaking, they always so act. Thirdly and finally, since each mode of acting is absolutely possible, although natural agents themselves cannot determine themselves to either of them, but would have to be determined through the concurrence of the first cause, a twofold concurrence for acting by two total actions would not be due to them, because it is not necessary to them and nature abhors superfluity; therefore also from the definition of the concurrence of the first cause those secondary agents cannot naturally act at once as total causes. Which reason will be declared more in the following point, and after its resolution the arguments adduced above in the second opinion will be better answered.