I. To the Question

A. The Opinion of Thomas Aquinas

1. Exposition of the Opinion

186. There is an opinion here [Thomas Aquinas, Sent. IV d.12 q.1 a2 q.2] that “in the case of natural actions substantial forms are not the immediate principle of acting, or the proximate active principle of acting, but they act through the medium of active and passive qualities as their proper instruments, as said in On the Soul 2.4.416b28-29, namely that natural heat is that whereby the soul acts. And therefore qualities do not act by their own virtue but in virtue of the substantial form. Hence their act has not only an accidental form but a substantial one as term; and because of this, generation is the term of alteration. Now such sort of qualities receive instrumental virtue from the fact that they are caused by essential principles; hence, just as the same being, the same as to species, remains in accidents by divine power after the substance is removed, so too does the same virtue as before remain in them. And therefore, just as they were able to cause a change for substantial form before, so are they also able now.”

187. And if argument is made against this that “nothing acts beyond its species” they reply that “nothing acts beyond its species by its own virtue; but it can, by the virtue of something else of which it is the instrument, act beyond its species, as a saw acts for the form of a bench” [Thomas, ibid. ad 2].

2. Rejection of the Opinion

188. Against this I ask what is meant by the ‘in virtue of substance’ that is said? Because whether he means an absolute or a relative [accident], I ask, what is it in? If he means the absolute that is substance or that is something in substance, then since the substance of bread simply does not exist [sc. after transubstantiation], it follows that an accident will generate by nothing or by non-being, or by virtue of nothing. If he means the absolute that is accident or something in accident, then nothing nobler than accident is there, and consequently, in virtue of such a something, an accident has no more power for anything more perfect than it has by its own virtue. But if he means the relation of accident to substance as to a prior cause, then since there is no relation to nothing, and the bread is not a being, it follows that nothing positive is being set down by what the ‘in virtue of’ is, and so the same as before [sc. an accident will generate in virtue of nothing].

189. From these words [nn.186-187], it seems that he is positing the virtue to be in the accident instrumentally, for he says that the virtue in accidents is caused, or that “they receive instrumental virtue from the fact that they are caused by essential principles of substance.” And then, since nothing in an accident is nobler than that accident, it manifestly follows that an accident has, through what is first said (‘in virtue’ or ‘through this virtue’), no power for anything more perfect than it has power for from itself or through itself.

190. But the true understanding of these words, ‘in virtue of such a cause’, seems, where the said words have place, to be this, namely that he is asserting the relation of inferior cause to superior cause, or more perfect cause, that concurs in the causing, just as was said above, that the influence which an inferior agent receives from a superior is not any form then caused, but is only a determinate order of causes in acting together or causing together [cf. Ord. IV d.1 n.170].

191. Again, what does not exist possesses no idea of cause with respect to a generated thing when it is generated, because the cause in act and the effect in act are and are not together (Physics 2.3.195b17-21 and Metaphysics 5.2.1014a20-25). And the fact is plain by reason, because non-being, when it is not, is not cause of anything, in any order of cause; now the substance that the accident affected and was accident of does not exist; therefore the substance has no idea of cause, proximate or remote, with respect to the effect caused by the accident, and consequently the accident does not cause anything in virtue of the substance, as in virtue of a superior cause.

192. Again, nothing is an instrumental cause with respect to that for producing which its sole active virtue is sufficient - the point is plain if ‘instrument’ be taken strictly, as a saw or axe are said to be moved mover instruments [Ord. IV d.1 nn.120, 317-318; d.6 nn.124-126]; for such an instrument does not have of itself a form sufficient for producing the effect, but only by the motion of the principal agent is that produced which is produced. If too ‘instrument’ be taken according to other modes posited above [ibid. d.6 nn.117-119], namely insofar as an inferior cause is said to be an instrument, or a form that this sort of cause receives from the motion of a higher agent (by which form it acts), still none of these instruments has, through its form, power for the effect in respect of which it is the instrument; but it is necessary that, for the effect, the co-cause it is instrument of concur with it at the same time. But as it is [sc. after transubstantiation], the accident, without any action of the substance, acts precisely by its form on whatever it acts on; therefore, in no way does it act for any effect in virtue of substance or as its instrument.

193. Again, the point can be argued through the principles of the above statements [nn.186-187] about an instrument that is a moved mover, because an accident in the issue at hand is not moved by substance, since the substance does not exist; therefore, the accident is not its instrument.These objections against may seem to be missing the point. For one could gloss Thomas’ position as that accidents act in virtue of substance (as the red of an apple acts on the eye) because they are really there, and they are really there because the substance they are accidents of is really there. But if accidents do nothing unless really there in an actual substance, so a substance does nothing through accidents it lacks (a green apple, for instance, causes no perception of red). So, it would seem that accidents act in virtue of substance, not because they receive some form from substance, but because they exist in virtue of substance. However, if they were to exist without substance (as they do by divine power in the Eucharist), then they would act through their own form in virtue of existing, but their existing would not be in virtue of substance. Thus the ‘in virtue of substance’ Thomas is talking about seems to refer, not to the form of the accident (redness, for instance), but to the existence of the accident. If so, Scotus’ objections would seem misdirected. However, Scotus returns to this issue later, nn.204-211, and argues that, on Thomas’ own principles, substance must be cause also of the form of accidents and not just of their existence. But be that as it may, for nothing prevents Scotus having his own different view on the matter regardless. ⁴³

B. Scotus’ own Opinion

194. I say to the question, therefore, that since a triple action can be posited to belong to accidents, namely one with respect to generating substance and two with respect to causing accidents (one with respect to sensation, the other real as to a passive thing that really has the contrary [accident]) - the first can in no way belong to a separated accident, not even instrumentally, as already proved [nn.191-193] - and this when taking ‘instrument’ for any cause that attains the end of the principal agent, whether for a second cause properly speaking, or for a part through which the whole acts, or for what then receives the active form by which it acts, or for what receives motion alone as an effect on the way to the principal effect (these ways of taking ‘instrument’ are plain above [refs. in n.192]). For in all these ways it is required that that of which it is the instrument concur in its own order as causer; and, when it does not exist, nothing causes in any order of causing.

195. But besides these modes, an instrument is called a cause that precedes as dispositive for the term [Ord. IV d.6 n.117], and this even though it have the dispositive action in its own virtue; and in this way it is very possible for an accident to be the instrument of substance, because it can cause an action dispositive for the term of the agent’s substance. But not even in this way can an accident be an instrument of substance in the issue at hand, because a substance that does not exist induces no term, nor can induce any term, at the end of the alteration caused by the accidents.

C. Response to the Arguments for Thomas’ Opinion

196. From this is plain the solution to the deduction for the opinion [of Thomas, n.186]; for the authority of the Philosopher in On the Soul [ibid.] only proves that heat is an instrument of soul in this last way [n.195], namely because it digests and alters food, so that at the end of the alteration a substance can be generated from it. Hence two actions are there and two principles of acting: because with respect to the previous alteration the principle of acting is heat, but with respect to the form of the flesh to be induced the soul or the form of flesh is the principle; and the first agent is said to be an instrument with respect to the second, not properly by subordination of virtue to virtue, but by subordination of effect to effect; hence it would more properly be called a dispositive agent than an instrumental agent.

197. And when it is said further in the deduction [n.186] that the accidents act in virtue of substance, what follows is only that they are instruments; but they are not instruments of a non-entity substance; wherefore from this the opposite follows [sc. that the separated accidents do not act in virtue of substance].

198. And when the further inference is drawn [n.186] that the action of the accidents has a term not only at the accidental form but at the substantial form - this I reckon to be false, save as at a remote term, which is in no way attained by the action of the accidental form but is what the term is ordered to that is attained by the action of the accident.

199. And when the proof is given [n.186] that the accident attains the term of the action because it reaches the passive thing into which the form is induced, while the substance cannot attain the matter as passive object on which to act because it is not separated from the passions by virtue of a natural agent (as said in On Generation 1.3.317b20-33) - I say that this consequence does not hold save in virtue of the following implicitly understood proposition, that ‘every instrument attains the term of the principal agent’, which is false in the issue at hand.

200. And when this seems to be proved by what he adds, that ‘generation is the term of alteration’ [n.186] - this proof can be drawn to the opposite. For generation is not the intrinsic term of alteration, but an extrinsic one is and of a different genus, and generation has its own term prior in genus to the proper term of alteration. But it does not follow that, because alteration has its own and sufficient causality with respect to what is essentially posterior, it has a causality by which it attains what is essentially prior; rather the opposite follows, namely that it does not have a causality by which it attains what is essentially prior. Therefore, in the way in which generation is the term of alteration, what follows is that the principle of alteration does not attain the term of generation save mediately, because it attains something that is ordered toward it.

D. Three Conclusions for the Solution of the Question

1. First Conclusion

201. This conclusion thus follows (and let it be the first for the solution of this question), namely that a separated accident can in no way be a principle of action for substance, and this an instrumental principle, by virtue of a substance that does not exist [n.194]. And along with this, it has also been made clear that not even a conjoined accident can be per se an attainer of substance as term [n.194], because the authorities adduced (from On the Soul and the like [n.186; Ord. IV d.1 n.317]) only take an instrument to be a dispositive agent.

202. And if it be argued, against this, that some form attains the term of generation immediately but the substantial form does not (because it is a principle not of acting immediately but mediately) - I concede the first proposition, but the second is false, because nothing is an instrument of any cause save of a superior cause in the genus of efficient cause. Therefore, if a conjoined accident is, for them [sc. Thomas, n.186], an instrument of substance, the substance will be the superior agent. But a superior agent naturally acts first and, if it is a natural agent, it does whatever it can; therefore, the substance, in the prior instant of nature but in the same instant of time in which it acts, acts as the superior agent, and the accident acts as its instrument. The substance will produce the term that it will be able to produce; but it can produce the whole substance, because the perfection of a produced substance does not exceed the perfection of the acting substance; therefore it will, in the instant of nature, produce the whole substance; therefore the accident will not produce the substance in any way, or the same thing would be produced twice.

203. Again, every merely passive power is in potency of contradiction,That is, has a potency for contradictory results. Cf. Thomas, On Metaphysics 9 lectio 9: “Every power is a power simultaneously for contradiction. But this is said of passive power, according to which something is said to be able to be or not to be, either simply or in a certain respect.” ⁴⁴ Metaphysics 9.8.1050b8-9; but substance is not in potency of contradiction for its proper attribute; therefore, it has some causality, different from the causality of matter, with respect to that attribute - and only the causality of the efficient cause, because not of the formal cause (the thing is plain). As to the final cause, it is not in discussion here.

204. And it seems that they [sc. Thomas and followers] must, according to what they say, concede this. For they say that the powers [of the soul] flow from the essence of the soul, and they say here [n.186] that an accident has instrumental virtue because it is caused by the essential principles of substance; but these features cannot be understood only in a passive way, for a receptive subject.

205. Again, if an accident is produced, and by some immediate productive principle which (according to you [n.186]) is an accident, I ask about the essential order in these accidents (not speaking of the accidental infinity in generators and generated of the same species that philosophers speak about [Ord. I d.2 n.46, II d.1 n.169]). For wherever there is an accidental order in generators, there must be (outside that whole order) some cause essentially more perfect [Ord. I d.2 n.54]. Therefore, with respect to singular accidents in the species of heat, give me a proximate cause essentially ordered to that whole species (and I argue the same way about individuals of the species). And there is no infinite process in an essential order. So, there will be a stand at some species of accident that will be caused, and not caused by any accident but immediately by substance. And consequently, substance will have the idea of active principle immediately with respect to accident.

206. This is confirmed by the Philosopher Metaphysics 7.9.1034b16-19, where the Philosopher says that “a property of substance can be grasped from these facts, that some other actually existing substance must necessarily pre-exist to make it the case that there is an animal, if there is an animal; but that a quality or a quantity pre-exist is not necessary save only in potency.” He maintains, therefore, that, in order for a substance to come to be, another substance must pre-exist to produce it; but in order for a quantity and a quality to be produced, there is no need for a quality or a quantity to pre-exist save only in potency. Therefore, something that is not actually a quantity or a quality can be the immediate productive principle of a quantity and a quality.

207. Again, Meteorologica 4.12.390a10-12 says, “A singular is that which exists as long as it has power for its own proper operation.”

208. And the like is got from Damascene, Orthodox Faith ch.60 [“Things that have the same substance, have the same will and operation”].

209. And although there is against these authorities [nn.206-208] an objection drawn from imperfect beings, yet it seems very unacceptable that the being among created things the most perfect as to genus should lack activity, such that its form could not be the immediate and proximate productive principle of some action.

210. And this argument is in accord with one of their principles [Thomas, ST Ia q.4 a.3]: that form is a principle of acting wherein the generator and generated are like each other; but the generated is like the generator principally in substantial form, and in accidents in a certain respect.

211. Nor can this result be avoided by adding to these statements that they prove the substantial form to be the principle of acting, but a remote one, both with respect to substance and with respect to accident, and that about these do the arguments proceed [nn.202-205]. This is not enough, because no one denies that there is some form in God that is the proximate principle of acting (not because God may act without intermediate causes, but because in his own order of causing he acts through nothing intermediate -beyond his own form). And so, in the issue at hand, let it be the case (which however has been disproved [n.200]) that an accident have some action for substance that is posterior to the action of substance; yet substance will be by its own proper form the principle of the action proper to it in its own order of acting.

2. Second Conclusion

212. The second conclusion for this solution is that an accident cannot be a principle for principally generating substance.

213. I prove this: every total agent is either univocal, and so it is as equally perfect as its product, or equivocal, and so it is more perfect; but an accident is altogether more imperfect than substance;     therefore etc     .

214. It is said in reply to this [Henry of Ghent, Quodlibet IV q.14] that some equivocal agent can be more ignoble than its effect, as whiteness in respect of the intellection of whiteness, and as the Commentator [Averroes], on Metaphysics 7 [com.31], relates from Galen about the virtue he calls ‘divine’, which is formative of the fetus and yet, if it is an accident, is not simply nobler than the formed fetus. And there can be a like difficulty about each living thing generated through putrefaction, which living thing is nobler than the heaven by which it is generated.It was a common opinion, derived from Aristotle, that some flies and grubs were generated by the sun from putrefying matter. That they are in fact generated from eggs, invisible to the naked eye, laid by parent flies and grubs was unknown. Still the sun would be needed to keep the eggs, and the decaying matter, warm enough for incubation. ⁴⁵

215. On the contrary: although the proposition ‘what is simply more imperfect in species or genus cannot be the total active principle with respect to something more perfect’ is as equally known to me as any proposition in philosophy - on whose denial I would not know how to prove any order of beings, or that there was a most perfect being; indeed [on this denial] it could be said, turning impudent, that the whole universe and everything in it was made by a fly; for if you argue that a fly is imperfect so, and if you say that the same thing which is more imperfect can produce what is more perfect, then, with this point in hand, there is no reason why something more imperfect so could not produce something more perfect so; nor, once this impudence is in place, can it be proved that the first cause is most perfect, excelling everything else in the creation - not even with the addition that it is an equivocal cause; indeed, the view could herewith stand, according to this impudence, that the first thing was most imperfect, or more imperfect than the things it caused - yet [although all this be so] I prove and argue the said proposition in a different way:

216. First as follows: a univocal cause has a univocal effect as the adequated term of its power; but, for you, a total equivocal cause is more imperfect than a univocal cause; therefore, it is impossible for the equivocal cause to be the total cause with respect to the effect, and thus God could not bring about the effect of any creature at all, which is an absurd thing to say. The consequence is plain, because an effect adequated to a more perfect power can in no way be from a more imperfect power.

217. Second as follows: whenever a univocal and an equivocal cause come together for the production of the same effect, the equivocal cause is simply more perfect. The point is plain from Metaphysics 12.6.1072a9-18; for, because of this, it is necessary to reduce the whole accidental order to some species essentially superior in causing, because a uniform difference of form must be reduced to a uniform cause; and so there must be for all generable and corruptible things some superior cause that is the cause of uniformity in the continuing of generation and corruption. - From this I have the proposition that ‘where a univocal and equivocal cause come together for the same effect, the equivocal cause is more perfect’. But that the equivocal cause could not act without the univocal cause, this belongs to some sort of imperfection in the equivocal cause. The thing is plain, for God can act without a univocal cause, but the sun does not have power for a perfect animal, although it does for an imperfect one; therefore any equivocal cause that has power by itself for the effect is simply more perfect than an equivocal cause that could come together with a univocal cause for causing the same thing. And consequently, an equivocal total cause has a double preeminence of causality over an effect: one that an equivocal cause universally has when concurring with a univocal cause, and it has another, because it has the perfection that the univocal cause adds in the causing and that many equivocal causes lack, even though far more perfect than univocal ones.

218. A third argument as follows: if the form of an equivocal cause were to give being formally to something, it could not give it a being simply more perfect than itself; therefore, if it more imperfectly than formally give being to something, it cannot give to it what is more perfect than itself. But when it gives being to something as efficient cause it gives it being in a more imperfect way than when it gives it formally; for it is not possible that any mode of giving being should be as perfect as the giving of being formally, just as neither can the divine essence give being to something in any genus more perfect than is the being that it gives formally.

219. Fourth as follows: if the thing caused be simply more perfect, although it be simple, yet it can, according to this understanding, be divided into two, namely into that in which it is equaled with the cause and into that in which it exceeds the cause. Let the first be called a, the second b; the effect according to a is precisely an effect adequate to its cause, because it is simply as equally perfect a being as the cause; therefore b either will be from itself or will be from nothing, because it cannot be from a or from the cause itself, because something more excellent over and above the effect adequate to the cause cannot at the same time be from the cause. And this argument can be taken from Avicenna in his Metaphysics, 6 ch.2.

220. I say therefore that, on account of no particular objections, must this universal proposition, which is known from its terms, be denied, namely that ‘what totally causes something cannot be more imperfect than what is caused (speaking of effective cause), and that an equivocal total causer is more perfect’, for it cannot be equally perfect, for species are disposed as numbers are [sc. a higher number is not equal to, but does include, a lower number].

221. Now the objection about whiteness and intellection [n.214] is not valid, as is plain from Ord. I d.3 nn.452-455, where the argument proves that whiteness is not the total cause with respect to intellection but only a partial cause. Hence it can very well be that the effect excels such a partial cause in some real perfection, which perfection it can have from the partial cause that is left, and so it is more perfect from the two together than from one of them, as was said there [ibid. nn.486-503].

222. The second and third objection [n.214], which go to the inducing or educing of the soul in living things (and that by the heaven, whether in propagated or putrefied things), where I reckon the difficulty to be almost the same - these objections have to be solved in Ord. II d.18.Missing in fact in the Ordinatio as it now stands. Scotus’ view must be looked for instead in Lectura II d.18 nn.27-39, 66-72. ⁴⁶

223. And let it be that there not appear that any other created cause could be found nobler than the soul (which is the term of such generation), one should concede that it was immediately from God first before denying the above now proved proposition [n.220].

3. Third Conclusion

224. Let the third conclusion be about the two actions contrary to the others [ nn.201, 212, instrumental or principal actions for substance], namely actions on the intellect and sense. I say that a separated accident (at any rate in the way that a quality of the third speciesThe reference is to the several species of quality listed by Aristotle, the third of which is the perceptible qualities that affect the several senses, Categories 8b26-10a11. ⁴⁷ is here separated, namely without a substance) can be the principle of both actions in the way it was before [sc. before when it existed in a substance, nn.194-195] - and this to the extent it is from itself (the reason for this addition will be plain in the solution of the following doubts [nn.230-238]).

225. I prove this as follows: in the case of any action of which some form is the total active principle, that form could, if it were to exist per se and in a manner fit for acting, be the principle of the same action; but quality is the total and formal principle of both the aforesaid actions [n.224], and when it is separated from substance, it is yet in quantity or, having extension as it is here [sc. in the Eucharist], it remains in a manner fit for acting, which is an extensive manner;     therefore etc     .

226. The major is plain, because when a total principle is in place and is under the idea under which it is of a nature to be principle, it can act as principle for that of which it is posited to be the principle.

227. The minor is proved in one way as follows, that nothing is taken away from this form by the fact that it exists per se save its subject; and the subject only makes a unity per accidens with it, but a per se principle of acting in a single order is a per se unity; therefore, the taking away of this subject takes nothing away from the per se principle of acting.

228. But this argument [n.227] only proves that the subject does not have the per se idea of principle in the same order as the accident; but there is no obstacle to prevent it being a per se principle of acting for the same action, yet in a different order (as is plain about ordered causes [cf. Lectura I d.3 n.372, II dd.34-37 nn.124-126]); and the per accidens unity of them [subject and accident] does not prevent unity of order.

229. Therefore the minor is proved in another way as follows: that form is the total principle of action which is the total principle of assimilating the passive object to itself - not only really, as in a real action, which is action on a contrary, but in intentional action, which is action on the senses. The first point is plain, because the formal term simply is like to the accidental form; therefore the accident can be the principle ‘by which’ of acting. The second point has a proof, because if the likeness in the senses falls away in some respect from the real likeness in the passive object [sc. the perceived object], then, on the part of this form as agent, it can as well be the total principle of this action as of the former; but if there is some further perfection in the sensation, this is not insofar as the sensation is from the sensible quality but insofar as it is from the sense power.

E. Doubts Against these Conclusions

1. First Doubt

230. But against these conclusions there are some doubts.

231. First, against the third conclusion [n.224] there is this doubt: for it does not appear that a quality’s action on the senses and on a contrary is different:

a. First, because a quality does not act through choice - therefore, as to how much is from itself, it acts uniformly; therefore, as to how much is from itself, its input into any passive object is the same, and consequently it puts a similar form into the senses and into a passive object, and consequently the action, as to how much is from the side of the agent, is not different.

b. Second, because where the active principle is the same, the action is the same (the proof of this is from the Commentator, On the Heaven 3 com.72: “if the nature is one, the action too is one”); but the formal principle and the proximate formal principle of acting both on the senses and on the intellect are the same; therefore, the action is the same.

2. Second Doubt

232. The other doubt is that this last conclusion [n.224] seems to contradict the two preceding ones [nn.201, 212]. I prove it as follows: because if separated accidents have power for every degree of alteration that the conjoined accidents had power for, then they have power for the corruption of the substantial form of the passive object on which they act; but the corruption cannot, by virtue of them, be corruption into nothing

(for a creature can annihilate nothing), nor into separated accidents (for a creature cannot make separated accidents to exist per se); therefore this sort of corruption is into some other substance - and thus, if the third conclusion be true, namely that separated accidents can be a sufficient principle for alteration, as they were before, [n.229], the result is that they can be a sufficient principle for generating substance, against the first and second conclusion.

F. Solution of the Aforesaid Doubts

1. To the First Doubt

233. As to the first doubt [n.231]: what an action is, and by what it is, will be stated in question one of the following distinction [d.13 nn.18, 27-71]. But positing here briefly what I believe to be true, that action states a certain respect arriving from outside (whether in the agent or in the passive thing), and a respect that corresponds mutually to the respect of passive undergoing, then, since passive undergoings in diverse passive things are of different and diverse idea (just as are the forms received in them), the result is that the actions of them will accordingly be different.

234. This is confirmed specifically in the issue at hand, because a passive thing receptive of a form as to real being is not receptive of the same form as to intentional being, On the Soul 2.7.418b26-27 [12.424a17-b3]: “For what is receptive of sound must be without sound” - at any rate, what is regularly receptive of the form in the latter way is not receptive of the form in the other way, especially in the case of receptive or susceptive material things. Therefore, an organ [sc. object of intentional action] and a contrary subject [sc. object of real action] are not receptive of the form according to the same being, because the one receives it intentionally, the other really; and consequently, since an agent acts on a passive thing according to that thing’s receptive potency (according to On the Soul 2.414a11-12: “It seems that the acts of active things are in the passive and disposed thing”), it follows that an agent does not act on this passive thing and on that passive thing with an action of the same idea.

235. And then, as to the objection about an agent acting by choice [n.231a], I reply that an agent acting by choice can act in diverse ways, with a diversity not only of unlikeness but of contradiction - as it is able not only to do this and that but to do this and not to do that. Now a natural agent, which is unlimited simply or in some way according to active perfection, is able to act for disparate results but not for contradictory results, because each natural agent acts on matter disposed to it, and does so necessarily. Therefore, the inference ‘it does not act according to choice, therefore it does not effect diverse forms in diverse passive objects’ does not hold, but what follows is that ‘therefore it does not act indifferently, or it does not of itself effect the form that it is able to effect or not to effect in such a passive object’. An example from the sun (and it was touched on in Ord. I d.2 nn.349-350), which although it have a certain indeterminateness as to causing diverse effects in diverse passive objects, is yet not indeterminate as to the contradictories of acting or not acting, but it necessarily does in any passive object whatever it can do in it.

236. As to the second objection [n.231b], one must say that there can be many formally distinct actions of the same active principle, provided however that the active principle not be single one limited in active virtue, as a single form is. And thus, all the authorities of the Commentator [n.231], and of anyone else, must be expounded of a form single in virtue as it is single in being of nature.

2. To the Second Doubt

237. To the other doubt [n.232], against the other two conclusions [nn.201, 212], I say:

In one way, briefly one could, by evasion, say that a quality is a principle of action on a passive subject having the contrary quality, and this according to any degree it had before, and this as concerns the part of active quality. But, because of the subject in which the contrary determines for itself some degree more than another, it is possible that it [= the active quality] would not have power for every degree of the contrary (insofar as the contrary exists in such subject) in the same way in which it had power for it before. And this response will be made clear in what follows [nn.240, 247, 251-254, 257, 264265].

238. It could be said in another way that although the quality would have power for every degree of alteration that it had power for when conjoined [sc. when not separated from a substance], the consequence does not hold that it could have power for corruption of substance. - The idea of the first remark [‘although the quality would have...’] is as follows, that generation cannot be separated from corruption (relating it to a natural agent understood in this way) without whatever is created corrupting something simply, leaving behind something at the end of the corruption (for it does not annihilate things). Now a creature cannot corrupt something into a per se existing accident; therefore, if it corrupts, it corrupts into a substance, and consequently if it not have virtue for corrupting something into a substance, it does not corrupt at all; but a separated accident does not have virtue for corrupting into a substance.

3. Objections against the Solution of the Second Doubt and their Solution

a. First Objection

239. But against this:

First, because a quality that has power for every degree of alteration preparatory to generation has power for a degree incompossible with the substantial form of the thing to be corrupted - and so it has power for corruption. The proof of the first part [“power for a degree incompossible.”] is that, if the quality does not have power to induce some degree incompossible with the substantial form, then the substantial form of the thing to be corrupted can stand with any degree inducible by the quality, and so the thing to be corrupted can, by no alteration, be corrupted.

240. I reply: the altering thing can never induce a degree incompossible with the alterable thing. The proof comes from the ideas of the terms, because a mover cannot induce a degree incompossible with its movable object (the proof of which is that the movable thing remains throughout the whole motion;     therefore , it remains under every degree induced by the motion); but nothing remains under anything incompossible with it; therefore etc     .

241. But when you infer [n.239] that ‘then the altering thing will, by alteration, never corrupt the substance of the altered thing’, I concede it. And I prove this by another reason a priori, because a naturally prior is not corrupted by something naturally posterior; but whatever is induced by an altering thing, as altering thing, is naturally posterior to the substantial form of the alterable thing; therefore by nothing such that is induced by the altering thing is the substance of the alterable thing corrupted.

242. I reply, therefore, that no substance can be corrupted save by a substance, just as neither can the opposite of a substance to be corrupted be induced save by a substance, as was proved above [nn.202, 206, 212ff.]; but a substance is not corrupted by a contrary quality save dispositively, because generation follows on the dispositive alteration unless something prevents it.

243. But on the contrary:

It would then follow that if the accidents of fire were the greatest (namely as great in quantity as the sphere of fire), and yet they were separated from substance, they could not corrupt a drop of water existing there, which seems impossible.

244. Something else follows, because if the accidents that do the altering have power for any degree whatever of alteration the way they had before, then they have power for the ultimate degree - and consequently, since the ultimate degree, when corrupted, disposes immediately for the corruption of substance, or its corruption is immediately accompanied by the corruption of substance, the result is that the substance will be corrupted;     therefore etc     .

245. To the first [n.243] it can be said: I concede that if the whole substance of fire were destroyed and all the accidents remained there, a drop of water put there would never be destroyed. And the reasons set down before [nn.242, 202, 206] have this as conclusion, because accidents cannot generate any substance, and the corruption of substance can only be into substance; because the corruption is not into nothing, nor into matter, nor into accidents, and especially by virtue of a natural agent, because nature cannot annihilate anything, nor resolve anything into prime matter, nor make accidents without a subject.

246. Lest, however, this be said to be too absurd and against sense, I say that, if any accidents were without a subject, a substance of any quantity and quality next to them would be corrupted, but not by them, rather by the created universal agent, namely the heaven, to which natural philosophers take flight - especially since the form to be here induced is imperfect and is totally in the active power of the heaven. And consequently, with no particular agent impeding but rather disposing, this form can be induced by the heaven, just as the heaven induces certain imperfect forms in the matter of corruptible and generable things. And if there were some form for inducing which the heaven did not suffice, one must flee to the simply first Cause, which would here induce the form for which the natural agent disposes it. Nor is this a fleeing to a miracle, because God as a matter of rule supplies every impotency of the whole creation, as is plain in the animation of an organic body by the intellective soul, where no miracle is posited. So here the whole of created nature would not suffice for the generation or corruption in question; and therefore, when nature makes disposition for it with ultimate disposition, God would as a matter of rule supply the impotence of nature.

247. To the second [n.244] I say that there is no degree of alteration on which would necessarily follow the corruption of the substantial form in the alterable thing; but the degree that is next in one alterable thing can fail to be next in another alterable thing, speaking with respect to the corrupter or generator intrinsic to the thing that does the altering. For let it be that some degree, which is as it were next to the degree that is incompossible with the form of water, would be induced in the water by some agent -corruption of the water would immediately follow if there were from the agent a form by which it could corrupt the water. But if there not be in the agent a form corruptive of the water, then the corruption of the water does not follow from that agent, but perhaps from some universal agent inducing the form for which the matter has been disposed. So here, if the water were altered by separated accidents to the degree that would be proximate to the corruption of water, in the way it is possible for a proximate degree to be there (and I speak thus because, in the case of indivisibles, nothing divisible is proximate to something indivisible), then indeed the corruption of the water would immediately follow from the altering agent, though in this case only extrinsically.

b. Three Other Objections

α. Exposition of the Objections

248. But there is still argument against this [n.238], that when some quality is in a subject, it can be the principle of acting toward something incompossible with the substantial form; therefore it can be here too [sc. in the Eucharist], because it was stated before [cf. n.186] that every alteration that an accident in a subject can cause it can cause without a subject.

249. Again, secondly, every degree of quality is of the same idea; therefore, what can have an action corruptive of one degree, that thing, belonging to the same idea, can, if it is more perfect, be the principle of action corruptive of a further degree, and so on about any degree. But it is possible for a separated quality to corrupt some degree of quality of a substance, as you concede [n.247];     therefore , if another separated quality be superior, it can corrupt any degree of the quality. But when every degree whatever of quality is corrupted, the prior substance does not remain because, without its natural quality, it does not remain; therefore etc     .

250. Again, thirdly, a natural agent could corrupt the qualities in the Eucharist, and so consequently it could induce some degree incompossible with those forms [sc. qualities] in their species; and yet it cannot induce some substantial form there, because there is no subject there; therefore, by parity of reasoning, separated qualities could induce in a passive object a degree incompossible with the quality [of that passive object], albeit they could not induce any substantial form concomitant with the opposite quality.

β. Solution to the First Objection

251. To the first [n.248] I say that an active quality existing in a substance cannot be per se the active principle with respect to some quality repugnant to the substance to be corrupted; but it can only be the principle of causing some quality in the sort of degree on which follows the corruption of the substance possessing that quality. But there [sc. when a quality exists in a substance] the corruption of the corruptingTreating the Latin ‘corrumpentis’ as intransitive and as meaning ‘undergoing corruption’. Otherwise the text seems hard to make sense of. ⁴⁸ substance follows this degree of the quality, while here [sc. in the Eucharist] it does not. For some agent conjoined with the accident is there that can corrupt this substance and generate another; while here whatever precedes the corruption of the substance would very well be induced, but on it the corruption of the substance by that agent does not follow, but rather by some universal agent, as was said above [n.247].

γ. Solution to the Second Objection

252. To the second [n.249] I say that, although this degree and that be of the same idea in themselves, yet not in comparison with any agent at all, because an agent that can corrupt a substance can corrupt the ultimate degree of the quality consequent to that substance, and only that agent can do so. But another agent can well corrupt other degrees not necessary to that substance.

253. Or one can say differently, and more plainly, that degrees can be of the same idea either in themselves alone or in themselves and in relation to a subject.

254. If in the first way [n.253], the proposition is false that says an agent of the same idea can corrupt things that are of the same idea [n.249]; for if these things are not of the same idea in relation to the subject (for instance because the subject determines one of them for itself but does not necessarily determine the others for itself), some agent can well corrupt one degree in such subject and yet not be able to corrupt the ultimate degree, because this latter is only corrupted with the corruption of the substance.

255. And if you make this argument, that just as substance necessarily requires the degree of the quality consequent to it, so that degree is repugnant to a contrary agent; therefore, just as you say the degree will remain as long as the subject remains [n.252], so it follows that, because of an active contrary, it do not remain.

256. And besides, what is posterior in generation is prior in corruption; but the quality (according to the degree necessary for the substance) is posterior in generation to the substance;     therefore , it will be prior in corruption. Therefore , it will be naturally corrupted before the substance is, and only by the altering cause as it is altering cause; therefore etc     .

257. To the first point [n.255] I say that if the contrary agent were as potent in destroying that degree as the substance is in conserving it, then the argument would have evidence on its side; but I say the substance has greater virtue for resisting the contrary corruptive of that degree than the contrary has active virtue for corrupting it. And the reason for this is that, by comparing active agent to active agent, the one simply more perfect in entity is simply more perfect in virtue; but substance has active virtue with respect to the quality that is consequent to it, and the contrary quality has an active virtue for corrupting it. But substance is simply more perfect than the contrary quality; therefore, the virtue of the substance is simply greater in resisting. And from this the probability is good that the substance is the active cause with respect to the quality consequent to it, because otherwise it would not resist the contrary corrupting its quality, nor would that quality be able to resist, because it is of itself something more imperfect than the corrupting contrary, were it posited, is more intense in its species than the quality is in its.

258. To the second [n.256] I say that that proposition [sc. ‘what is posterior in generation is prior in corruption’] is only true of things that are ordered in a generation and corruption pertaining to the same genus, of which sort are ordered forms (according to those who posit many forms); for as there the more universal form comes first to the matter, so it departs last. But as to substance and proper quality (which is consequent to the substance in the degree to which it is necessary for the substance), the proposition is false; rather, the quality is both induced later and corrupted later.

259. And if you ask, ‘by what is this sort of quality induced, whether by the generator as generator or by the alterer as alterer?’, and if you ask similarly, ‘by what is it corrupted, whether by what is corrupting the substance as it is corrupting it or by the alterer as it is inducing an opposite quality in what has been generated?’ - I reply: the proximate effect of a cause equivocal in species is caused in any individual by an individual of the equivocal cause. The reason is that individuals of the same species do not necessarily require causes different in species; for it is possible for the same specific nature in this individual to be produced by a cause of the same idea as that by which the same nature is caused in another individual; because the same inducing formal principle is sufficient for the same formal term; and that which, here and there, has the same formal term does not necessarily require a productive cause of a different idea,

260. From this proved proposition [n.259] about equivocal cause and proximate effect, I conclude that a quality necessarily consequent to a substance according to its species is caused in any substance by a substance of that sort; because the first quality is only caused by a substance; therefore any quality can be caused by it as well. And consequently, since an equivocal cause has more virtue than a univocal cause, then, if the univocal cause could induce the effect, the equivocal cause would still precede it, as the Philosopher says about a big flame and a little flame, On Respiration 4.469b31-70a5. The quality, therefore, of a generated thing is not induced by any alterer as it is alterer; that is, a quality is not the formal principle of inducing the quality.

261. And if you argue that then the previous alteration does not have a term - this is not unacceptable about a term per se of the same genus, because it has an extrinsic term, the substantial form of the generated thing.

262. And if you ask whether the quality of the generated thing is induced by the substance that generates it, I say that, although it could be induced by that substance, yet more probably it is induced by the generated substance itself, because though agents that have the same and equal virtue could induce the same form in the same passive thing, yet the generator or agent has the passive thing the more immediately conjoined to it the more it acts more efficaciously than the other equal things. But if it is the passive susceptive thing of the term of its action, as in the issue at hand, it is a passive thing more immediately conjoined to itself, and consequently the generator there will not precede the generated substance, because it is not prior to itself in perfection but only in duration. Now the generated thing is equal in perfection to, and more immediate than, itself as passive, and this can well preserve how such inducible equivocal forms are induced by whatever is in the generated thing itself; but such an equivocal agent would not be said to be able to induce the form in another passive thing (just as one will cannot induce volition in another will, yet it can well induce volition in itself).

263. From this is plain what the preceding quality is corrupted by, because it is corrupted by that by which the quality proper to the generated thing is induced, as was said [n.262]. Or one can say better that it is corrupted by that which corrupts its subject; but this is the thing that is generating the contrary substance - and then the quality of the corrupted thing is not corrupted save per accidens. However, the generated thing’s induced quality, which has some degree that was simply incompossible with the substance to be corrupted, is itself induced per se by the action of the generated substance, although not by a change, because the subject did not previously exist lacking that quality.

264. Now these things which have been said are not only true of an accident separated from substance, but also of an accident existing in a substance, because there the substance as possessed of quality does not induce a degree of it compossibleThe text says ‘compossible’ but a variant reads ‘incompossible’, which latter may be right. ⁴⁹ with the substance to be corrupted; but as a substance it corrupts a substance and consequently corrupts its quality; and as substance it generates substance; and the further degree proper to the substance to be generated, which was previously incompossible with the substance to be corrupted, is from the generated thing itself.

265. Hence is manifestly clear the falsity of this proposition, ‘every substance is corrupted for this reason, that some degree is induced that is incompossible with its own proper quality’; rather, never is a degree incompossible save in some substance already generated, otherwise the incompossibles would exist together. Nor can any degree induced or inducible by an alterer, as it is alterer, corrupt a substance, because nothing posterior in genus can be the cause of corrupting something prior in genus.

266. From this is plain the answer to the objection that can be made about water which could not corrupt fire [cf. n.243], because the fire simply has a nobler and more perfect active virtue. - I reply: it is not said that a more imperfect thing cannot corrupt a more perfect one [cf. n.245] (speaking of species compared to species), but that an active thing more imperfect in genus cannot corrupt a being more perfect in genus (because it can only induce something more imperfect in genus, and this more imperfect something cannot be successor to the corruption of a thing more perfect in genus). Now an accident cannot be properly successor to the corruption of a substance, because if it alone were to succeed to it, the substance as substance would be quasi annihilated. But an imperfect thing of the same genus is not so, because a more imperfect thing (in that it can induce something like itself) can induce something that can succeed to the corrupted thing of the same genus.

267. One could also say that between a perfect and imperfect thing of the same genus there is a formal repugnance, on account of which the one can corrupt the other; but between a perfect thing of one genus and an imperfect thing of another genus there is no repugnance save only a virtual one, the way the prior is repugnant to the opposite of the posterior, and the posterior to the opposite of the prior. Now the posterior in genus has only power per se for the opposite of its genus, and therefore not for the corruption of the prior in genus, to which it is not opposed save indirectly.

δ. Solution to the Third Objection

268. As to the third [n.250], I concede that the separated species could be corrupted by a created agent, as will be stated in the following article [nn.432-437], and as will also be stated in what way a substance there may be generated or not generated [nn.490-499].

269. But if the argument be formed in this way: ‘once separated accidents are posited, as the heat of fire in a quantity, not only the most perfect degree of the heat but even the ultimate degree could be corrupted by a substance altering it, or by some other separated quality, by a contrary or more active thing, as a separated quantum of cold. But this separated coldness is not of greater virtue or more active by the fact the heat is separated than if the heat were in a substance as in a subject; therefore if the heat were in the substance of fire, the separated cold could still corrupt the ultimate degree of the substance of fire; and then the whole main argument stands [n.250], that the heat cannot be corrupted unless the substance of the fire be corrupted, nor can it be corrupted unless another substance be generated, and so the separated cold could generate a substance’ - I reply that, by positing the heat of fire and the cold of water in separated quantities, if the coldness, in accord with intensity in its own species, were simply to overcome the heat in its species, I concede that any degree, even the ultimate degree, of the heat could be corrupted by the cold; but it does not follow that likewise the ultimate degree of heat could be corrupted when the heat is in fire.

270. The reason is this, that the quantity that is the subject of the separated heat does not determine for itself necessarily a degree of heat that is no more the lowest than the highest; for it does not have an active virtue or a necessity with respect to any degree there at all; and therefore what can corrupt one degree in such a subject can corrupt this degree and that degree and any degree you like.

271. Hence these degrees are of the same idea in themselves and in comparison with the subject, and the subject has an equal determination or lack of determination for any degree at all, and conversely; but it is not so when the heat is in the fire; for fire does not determine for itself necessarily the supreme degree, but the degree is in the fire contingently, and therefore if that degree could not resist the cold corrupting it, the subject will not resist it either, because it does not necessarily require that degree, but determines the lowest degree for itself. And therefore, although the lowest degree could not resist the corrupting contrary, yet the substance of fire, which is of greater virtue, can resist the corrupting contrary; for the substance of fire has more power for preserving the effect than the cold has for corrupting it. The substance will therefore preserve that degree as long as the fire is remaining in its being; and therefore, unless there is something corrupting the fire in itself, the degree will not be corrupted.

272. When, therefore, it is said [n.269] that the cold is not of greater virtue or more active by the fact that the heat is without a substance than if the heat were in a substance - I concede that in itself the cold is not more active, but it can act more on the contrary, because this separated contrary lacks a cause preserving its being, but when it is conjoined [sc. with a substance] it does have a cause preserving its being.

273. And this reason [n.272] is universal about contrary causes formally or virtually coming together on the same passive object; for one cause is not simply more or less active than the other because it comes together with it on the same passive object; but yet one acts less on this object by the fact that the other comes together with it, for the other impedes it.