Disputationes metaphysicae

1. Celebrated is that division of cause into four genera of causes, namely material, formal, efficient and final, which Aristotle hands down, Metaphysics V, c. 2, and Physics II, c. 3 and following; the exposition of which division depends altogether on the exact understanding of the individual members, which we shall pursue at length in this whole treatise; and therefore we shall now propose in common only those things which can be doubted about this division, and dispatch them briefly. The first is whether all those members are truly and properly contained under the thing divided. The second, whether they are distinguished and opposed among themselves. The third, whether they sufficiently comprehend the whole thing divided. The fourth, whether cause is proximately and immediately divided into those members, or some intermediate division can be thought out. The fifth, whether that division is lowest or atomic, or whether the individual members can be divided into others. The sixth, whether it is univocal or analogous.

The four proper genera of causes

2. The assertion is proved from experience.—To the first doubt it must be said that all those truly and properly participate the notion of cause; and therefore cause is deservedly divided into those four members. This assertion, besides the common consent of all after Aristotle, is proved thus. For that those four are found in things or in the effects which we experience can easily be declared by supposing that something new comes about in the nature of things; which is so evident from the perpetual vicissitude, alteration, generation and corruption of things that it would be superfluous to prove it by arguments. If, then, something comes about anew, some other thing is necessary by which it comes about, because the same thing cannot make itself; and this we call the efficient cause. Which either produces its effect from nothing, or from some thing which it presupposes for its action; the first cannot be said universally, for it is evident by experience that neither does the artificer make a statue except from wood or bronze, nor does fire heat unless something is supposed to it which receives heat, nor effect fire except from wood, tow or another similar thing. Indeed this mode of acting is so proper to natural causes that the philosophers who attended only to them took thence that axiom: From nothing nothing comes. That subject, then, which is supposed for the action of the efficient cause, we call the material cause. But it is necessary that the efficient cause introduce some thing into such a subject; otherwise it would effect nothing new, against the hypothesis posited. That, then, we call form, whatever it may be, of which we shall see afterwards. Finally, since causes acting per se do not act rashly and by chance, as is evident from the very experience of things, and especially in human actions, so that the matter is beyond controversy, it is necessary that besides those three there be also an end for the sake of which the efficient cause operates. These four members, then, are found in things, whether all of them are found in individual effects or not; for this will be to be inquired afterwards; for at present it is enough that these are found in the universe of things.

3. Matter is truly a cause. Form is properly a cause. The efficient is truly a cause. Whether the end is a true cause.—But that each of these is a true cause can easily be proved of the material, formal and efficient; for each of these manifestly flows some being; for matter is defined by Aristotle as that from which, being present in it, something comes about. Where by the particle from taken with propriety matter is distinguished from the other causes; but by the particle being present in it is separated from privation, and the proper influx is declared by which matter, and universally the subject, offers itself, so that from it the being of the whole may arise. Similarly the form offers itself so that by it as by act the composite may be constituted; indeed form is frequently wont to be defined as the intrinsic cause which gives being to the thing; for matter is as it were a certain inchoation or foundation of being itself; but form consummates and completes it; on account of which it is called by Aristotle in the places cited the notion of the quiddity. Likewise these are numbered among the intrinsic principles of the natural thing, or rather those two alone are the principles constituting the natural thing; but they are per se principles, since they are most of all necessary and essential, and they give being in the way which has been explained; they are, therefore, proper causes. Of the efficient too it is evident, because by its action it effects that the thing has being which it did not have before; and to this its action per se and directly tends; therefore the efficient is as it were the fountain and principle per se flowing being into the effect; which being of the effect is distinct from the being of the efficient; therefore the whole definition of cause belongs most properly to the efficient. But of the end there can be some reason for doubting, because no real being is presupposed in it by which it could cause; but because of this one must speak more fully in the proper disputation, now it is briefly declared, because, although the end is last in execution, it is nevertheless first in intention, and under that notion it has the true notion of principle; for it is the first which excites or moves the agent to act; but it is a principle not feigned but true and real, because it truly excites and moves. Whence, as it has sufficient being by which it can exercise such a notion of principle, so also the notion of cause; but that being, although it is in the mind, is not outside the breadth of real being, and therefore can be sufficient for such a notion of cause. Again, a principle of this kind is not per accidens but per se; indeed from it the causality of the agent has it that it tends per se and orderly into the effect; and by this reason it per se flows being into it; therefore the definition of cause belongs truly and properly also to the end.

4. The first objection.—The Stoics recognized only the efficient as a true cause.—The second objection.—But against this opinion someone can object Augustine, Eighty-three Questions, q. 28, saying: Every cause is efficient. Which opinion he seems to have taken from Plato, in the dialogue on the Beautiful, or which is entitled Hippias Major, where he signifies that cause and efficient are the same and that the end cannot be called a cause; which he confirms both because it is an effect, and because there cannot be a cause of the efficient cause itself. That this was the common opinion of the Stoics, namely that the efficient cause alone is a true cause, Seneca reports, Book VIII, Epistle 66, where he himself also approves it: Since if all things (he says) without which the effect cannot come about are to be placed in the number of causes, more would have to be numbered, namely time, place, motion, etc., without which no effect comes about; one must, therefore, stop at the one efficient cause, but the others are as it were aids of this cause, or necessary conditions. Otherwise it could be objected at the other extreme from Socrates in Plato, in the Phaedo, that the end alone deserves the name of cause, for the whole cause of the thing is that for the sake of which it comes about; but all the others are only conditions required in order that the thing come about; whence to the question on account of what the thing is or comes about only the answer through the final cause satisfies.

5. The first objection is unravelled together with a difficult place of Augustine.—To the former objection, the place of Augustine is difficult; for he denies there that it is to be asked why God willed to create the world, because this is to ask the cause of the will of God; but every cause is efficient, which cannot have place in the divine will; where Augustine seems plainly to confound the final cause with the efficient; for he who asks why God willed to create the world does not ask the efficient cause, but the final. But it must be said that the sense of Augustine is that a cause is not to be sought why he willed to create the world, so that some proper cause of the will of God itself is thought to be, because, if the divine will had some cause of this kind, it would have an efficient cause; not because end and efficient are formally the same, but because nothing can have a proper extrinsic final cause without having an efficient, either because the end itself does not cause without efficiency, as many hold; or because the end proximately moves the efficient to effecting. When, therefore, Augustine says that every cause is efficient, he is speaking of extrinsic causality, which is never without the intervention of the efficient cause; yet Augustine does not intend to exclude that another genus of causing can be conjoined with that cause. Others answer more briefly that Augustine spoke strictly of cause as it expresses a relation to an effect also strictly taken and denominated from the verb to effect. But this can scarcely be accommodated to Augustine’s discourse, for he who asks why God willed, etc., does not ask a cause so strictly taken.

6. Plato admitted as many genera of causes as Aristotle.—The sense of the ancient philosophers on this.—Why the efficient usurps the name of cause by antonomasia.—To Plato, it is certain that he posited all the genera of causes which Aristotle posited, and perhaps more, as we shall see afterwards. And in the cited place he does not say that cause and efficient are the same, as is attributed to him, but conversely he says: The efficient is nothing other than cause. Which proposition cannot be simply converted, as is self-evident. But thence he does not infer that the end is not a cause, but infers that that which is made by the efficient cause is distinct from it, because a cause cannot effect itself. But of the other philosophers I think that they dissent from Aristotle in words rather than in the thing. For they do not deny the necessity and the concausality of matter, or form, or end; but they differ in names: rarely do they call matter something prerequired; but form they judge should rather be called an effect than a cause, because the whole causality is terminated at it, or at most they call it part of the cause, as Seneca speaks above; but the end they call in some way a cause, or rather a concause with the efficient, or something supervening on the efficient, by means of the purpose or intention of the end, so that it can cause. Moreover the efficient cause has an influence both more real and in a certain way more immediate to the effect than the end; and better known and in a certain way more proper than matter and form, and also prior to them; and therefore the name of cause is sometimes wont to be taken by antonomasia, or also by reason of first imposition, for the efficient cause. Nevertheless, considering the thing itself physically, there is no doubt that each of the said causes has the true and proper notion of cause, and in its genus total and plainly diverse, as we shall say in the second point; and therefore Aristotle much better numbered these distinctly under the common notion of cause.

7. Why place, time and the like are not causes.—Nor does the reason adduced from Seneca stand in the way at all; for not all things without which the effect does not come about are numbered among causes, but only those which per se flow into the effect. Which place does not have, because it is something extrinsic; or, if the discussion is of intrinsic where, that is not presupposed but follows in the effect as a certain accident of it. And the same holds of time; for as it is a common measure, it is extrinsic; but as it can be intrinsic, it is only the duration of the very motion by which the thing comes about, when it comes about successively; but that motion is not a cause, but is rather the actual influx itself of the efficient cause successively, as will be declared below. But matter, although it is something prerequired for the action of the agent, nevertheless in the very instant or time in which the agent acts, matter too per se flows into the effect, indeed even into the very action of the agent, if it operates from it, as we shall see afterwards. But form, although it is the effect of the agent or also of the matter, is nevertheless the cause of the whole composite, completing its essence. And although it is part of the composite, it is nevertheless in its genus its total cause, nor is there reason why it should be called part of the cause, because it is neither part of the agent nor of the matter. But if it is called part of the cause with respect to the whole causality necessary in every genus for the effect, in this way matter and efficient too can be called part of the cause; yet it is an improper expression, because all those do not compose one cause, but an aggregate or required number of causes. And the same holds proportionally of the end; for, although it is required on the side of the agent in order that its action come about not rashly but by design, it nevertheless has a proper and per se influx diverse from the influx of the agent; but of what kind that is, and whether it is always necessary, we shall say below.

8. In moral things the end is the more excellent cause.—Whence to the other part of the objection the answer is that Plato and Socrates in that place speak morally rather than physically. For in moral things the end is in a certain way the whole cause of actions or effects, not that the other causes are excluded in so far as they are physically necessary, but that all the others take from the end as it were the first reason of causing. Whence the end can in a certain way be called the only cause, because it is so a cause that it has no prior cause or reason; but all the others are so causes that they have some prior cause or at least prior reason of causing; which I say on account of the first efficient cause, which is God, as we shall declare below. But if force is put on the word on account of what, it must be said that strictly taken it is accommodated only to the end, but more broadly it is also wont to be extended to all causes. Indeed Aristotle above thence proves the aforesaid genera of causes, because through all of them the question on account of what is wont to be satisfied; for we say that man is mortal on account of matter, and lives on account of the soul, etc.

The mutual distinction of the four causes

9. From these it is easy to dispatch the second point, about the distinction of these causes. But the discussion can be of distinction formally and precisely in the notion of cause, or of distinction as it were material or real in the being of being. The former distinction is that which pertains to the present point, which it is certain is found between these members. First, from the testimony of Aristotle, because otherwise the division would be vicious. Secondly by reason, because cause, as cause in act, is formally constituted through actual influx into the effect; but in those four members there are influxes of diverse notions; therefore. The minor is proved, because the influx of the material and formal cause is intrinsic through internal composition, but the influx of the efficient and final cause is extrinsic. Again, the influx of matter is after the manner of potency, but of form after the manner of act. Likewise the influx of the efficient is through real action or change; but the influx of the end is through intentional or metaphorical change; therefore all these causalities are formally distinct; they constitute, therefore, causes in act formally distinct. Whence also the notions or powers of causing of these causes are distinct; for matter causes in so far as it is passive potency; but the efficient in so far as it has active potency over another; but the form in so far as it has the power of actuating through itself; but the end in so far as it is good and through goodness has the power of alluring the effect; all of which will be expounded more fully in what follows; nor does a special difficulty occur here about this part.

10. The same thing can exercise the functions of diverse causes with respect to diverse effects.—But about the real or material distinction of these causes it can be doubted whether it always intervenes, or whether it can happen that altogether the same thing has several of the enumerated notions of causing. But this can be asked either in order to diverse effects or to the same. In the former way it must be said that a real or material distinction is not necessary between the said causes, because it is not repugnant that altogether the same thing in order to diverse effects have several causalities of diverse notions. For the same form is the end with respect to the generation or alteration through which it comes about, and is form with respect to matter and the composite, and is the efficient principle with respect to action on another, and can be the material cause of its properties, as is the rational soul in so far as it is the subject of the intellect or will. For these influxes or causalities, however diverse in notion they are with respect to diverse effects, do not have repugnance among themselves, nor is it repugnant that they proceed from the same thing; because, just as the same thing is capable of diverse respects in order to diverse things—for it is similar to one and dissimilar to another, the principle of one and the end of another—so it can in order to diverse effects participate diverse respects of causing. The a priori reason, finally, is that the same created thing can in its entity include act mixed with potency, and therefore can be compared to one thing after the manner of formal act, but to another after the manner of a subject; but formal act, since it gives being to the thing, is at the same time wont to be the principle of acting on another, because operation follows being; and finally, because such act is some good, it can also be the principle of metaphorical motion. So, then, it is not repugnant that all these genera of causes meet in the same thing with respect to diverse things.

11. But if sometimes they are not conjoined in some thing, it is not from the formal repugnance of such causalities in order to diverse things, but from a peculiar condition. And sometimes it comes from perfection, but sometimes from imperfection; for example, God can be the efficient and final cause, yet not the material with respect to anything, because he is pure act and has no passive potency; nor can he exercise formal causality either, because this requires an incomplete and imperfect entity. And for the same reason angelic substances cannot exercise formal causality; but because they are not pure acts, they can in some part exercise material causality, at least with respect to some accidents; and because they are not pure potency, they can have some notion of effecting, and much more of finalizing. But conversely prime matter, although it can exercise material causality, nevertheless, because it is pure potency, participates neither formal nor properly effective causality; yet, because it is not so pure potency that it does not have some entity and actuality, it can have some final causality, by reason of which the soul desires its body and any form whatever matter. But the substantial form, although it can exercise formal, efficient and final causality, yet not substantial material causality (so to speak), because it is not passive potency in the genus of substance. But with respect to accidents it can sometimes exercise this causality, which belongs properly to a subsisting form, for that form which on account of its imperfection cannot subsist of itself is not able of itself to sustain accidents either. And in this way one can easily run through the accidental entities, in so far as they can participate the aforesaid notions of causing.

12. With respect to the same thing the same thing cannot undergo the functions of form and matter.—Form and efficient with respect to the same thing cannot coincide in the same.—But if these causes are compared to one and the same effect, there is a somewhat greater difficulty. And indeed in some there is clear repugnance, but in others conversely there is manifest possibility, but in some the matter is controverted and doubtful. Thus that the same thing in order to the same be at the same time material and formal cause is plainly repugnant, because these causalities require formally opposite conditions, such as are to be in potency and in formal act; whence, if the discussion is of a proper substantial form, it always requires a real distinction from its material cause, and the same holds in an accidental form which has its proper entity. But because there are some accidental ones which are only modes of substance, as local presence, or if there is anything else of this kind, in these, as the notion of form is imperfect, so a modal distinction suffices. It is always necessary, however, that the formal and material cause with respect to the same composite be distinguished really or from the nature of the thing. Next it is also evident that the formal and efficient cause cannot be conjoined in the same thing with respect to the same effect; because form exercises formal causality in that in which it is, but efficient with respect to another form or composite; and therefore form as informing either is supposed to the action as a principle of acting, or follows as the effect or formal term of the action; and therefore it cannot happen that formal and effective causality belong to the same form with respect to the same thing, for they include repugnant relationships.

13. Whether form can flow together with end into the same entity.—Again it is also clear that final and formal causality can in a certain way agree in the same form with respect to the same thing, but in a certain way cannot. For if they are compared to the same subject or supposit, they can excellently agree in the same thing; for the same form both is the end of matter and informs it, and the same beatific vision is the form of the intellect and its end and beatitude. And the reason is that the form itself, as informing, and its information, is the good and perfection of the subject which it informs; and therefore it can be compared to it at the same time in the notion of form and end. But if the comparison is made to the composite itself which is constituted through the form, then the same cannot be form and end with respect to the same, because the form is not the end of the composite, but rather the form is for the sake of the composite as for its end. But if they are compared to the action or generation, with respect to it too the same is form and end. In which sense Aristotle, to be cited below, seems to have said that end and form coincide in the same thing in number; yet under that respect, although the form is properly the end of generation, it is nevertheless not properly its formal cause, but only principle, as I was saying in the preceding section.

14. Whether efficient and end are conjoined in the same.—Whether matter admits some notion of end in its entity.—Moreover one must speak in almost the same proportion of the end and the efficient; for according to a certain notion of end they can belong to the same thing, but not according to another. For a twofold end, as we shall see below, is wont to be distinguished, namely the end for the sake of which the action comes about, or to which, or in whose favour and advantage it comes about; as in healing, the end for the sake of which is health; but the end to which is the man himself for whom health is procured. The former end, then, cannot be the same thing as the efficient cause, because it is its effect; but the latter end can excellently be the same thing as the efficient cause, for often the efficient operates for its own sake; and in this way God is at the same time the first efficient and the last end of his works. And according to these is easily understood that common saying of Aristotle, Physics II, c. 7: End and form coincide in the same in number; but end and efficient in the same not in number but in species; for he speaks of the end for the sake of which, or which through the action is formally intended and comes about; of which we have already said that it is distinguished from the agent as its effect, and therefore cannot be the same in number with it. But that it is the same in species happens in univocal agents, not in all, as Aristotle himself indicated. But how formal and final cause can be conjoined in the same thing in number has already been declared. But I add that some notion of end can also be conjoined in the same thing in number with the material cause; for the subject of accidents is both their material cause and their end; for, as I was saying, the proximate end of health to be procured is the man, and among other ends form is induced into matter for the sake of preserving matter itself; for, because the notion of end is founded in goodness, which is transcendental and is found in part in every entity, therefore some notion of end can be conjoined with any other cause whatever.

15. Whether the efficient can be the same as the matter.—It only remained to compare the efficient cause with the material, whether each notion can be conjoined in the same thing with respect to the same effect. And indeed, speaking of the material cause of natural substances, it is certain that the material and efficient cause cannot be conjoined in the same thing in order to such an effect, because matter cannot be the efficient principle of the form to be educed from it, and consequently not of the whole composite. But speaking of the material cause of accidents, there is greater doubt whether the same material cause can be the efficient of the same. But this efficiency can be understood as twofold: one, through natural resultance; and speaking of this there is no doubt that those causalities can be conjoined, and so it is commonly said that the soul, for example, has a threefold causality on its natural powers, namely final, material and efficient; and many think that this genus of activity is not repugnant even to prime matter on its proper property, which is quantity. The other efficiency is per se and through proper action, and of this there is greater difficulty; but it coincides with that question, whether everything which is moved is moved by another, or (what is the same) whether agent and patient are always distinguished, at least according to the proximate principles of acting and receiving, which we shall treat afterwards in disputing of the efficient cause.

Whether the division of cause into four genera is adequate

16. Instruments are to be placed under the efficient, not the material cause.—Concerning the third point, whether these four genera sufficiently divide cause, various difficulties are wont to be proposed about instrumental, dispositive and objective causes. But these and similar ones have no difficulty, for the instrumental cause is a certain species of efficient cause, as we shall see afterwards. Nor can it with any foundation be reduced to the material cause, as Philoponus falsely thought out, Physics II, text 27, unless perhaps we speak of the dispositions of matter, which are wont also to be called instruments; but these, unless they have efficiency, are in truth not instruments; but if they have efficiency, as such they are not dispositions nor do they pertain in any way to the material cause, but to the efficient, which they either help or whose place they take. But the dispositive cause is commonly reduced to the material, because it prepares matter for form. But this denomination seems to be only through a certain attribution; for, if we speak with propriety, a true disposition is a certain formal cause, for it does not dispose except by informing the subject; for heat in wood does not dispose to the form of fire except by formally heating the wood; but I speak of true and proper physical and positive disposition; for in the vulgar way any removal of an impediment whatever is wont to be called disposition, or any necessary condition whatever, as application to acting or something similar; and in these there is no true causality, but only per accidens.

17. Of what genus is the causality the object exercises on the power and its act.—I call the objective cause the object with respect to the power or act. In which object a twofold relationship can be considered: one of moving, the other of terminating. The former with respect to the cognitive power is efficient causality, whether the object is considered in so far as it moves by impressing a species or in so far as through the species it concurs to the act; but with respect to the appetitive power it is final causality, either proper and formal, as in the rational appetite, or material and imperfect, as in the sensitive, which we shall see afterwards. But under the latter respect some reduce the object to the final cause, because the power and act tend into it as into an end. Nor does it stand in the way that this relationship is essential, because it is not repugnant that some thing be essentially ordered to its end. Others reduce it to the formal cause, in so far as the object gives species to the act; for whatever gives species has the notion of form; but they say that it is not an intrinsic but an extrinsic form. But I would more willingly deny that the object under this notion exercises some true genus of causality, but only that of a pure specifying term, not through some true influx which would constitute a cause, but through the mere relationship of another to it. Nor did Aristotle ever mention that extrinsic formal cause, nor did he call the term of motion the cause of motion, although he said that it takes its species from it; and the same holds of one relative with respect to another, or of the term of a relation as such. Nor does St. Thomas speak otherwise, as may be seen in I-II, q. 1, a. 3. But these are easy, and almost about the mode of speaking.

18. Whether the exemplar is a genus of cause distinct from those enumerated.—The chief difficulty in this point is about the exemplar cause, which Plato adds to the four enumerated by Aristotle, as is evident from the Timaeus and Phaedo, and Seneca reports, in the cited Epistle 66. But of this matter, on account of its gravity, we shall institute a proper disputation. Now we briefly concede to Plato that the exemplar exercises true causality, which Aristotle was not ignorant of, for here, in enumerating form, he adds also exemplar; and therefore perhaps it is not necessary to increase the number on account of this cause, which we shall examine in the said place.

Whether the aforesaid division of cause is immediate

19. The division of cause into internal and external is higher than the aforesaid.—The most immediate division of cause into real, strictly, and intentional.—Concerning the fourth, that division can seem immediate, because Aristotle proximately divided cause into those four members. But nevertheless it must be said that that division is not immediate; for agreements among some of these members can easily be thought out, by reason of which other prior divisions of cause into fewer members are constituted. So, then, cause can first be divided into internal and external; the internal again into matter and form; of which it cannot be doubted that they agree peculiarly in the mode of causing; for they give being to the effect by conferring on it their own entity in number and internally composing it; but the efficient and the end cause far otherwise, and agree in this, that they do not intrinsically compose the effect, and therefore are commonly called extrinsic causes. Therefore in the notion of cause a common notion of matter and form can be abstracted which is not common to the other causes, and conversely; cause, therefore, is rightly divided immediately into intrinsic and extrinsic, and then the former into material and formal, but the latter into efficient and final. In another way too another more immediate division of cause could be thought out; for the three other causes besides the final agree in this, that they confer to the being of the effect through real influx, and therefore require real existence for their causalities, as we shall see afterwards; but the final cause flows intentionally, and therefore can cause before it really exists in itself. Cause, therefore, can rightly be divided immediately into real and intentional, taking that term real strictly in the former member; for, if it is taken in its whole breadth and transcendence, it also belongs to the final cause. And again real cause is divided into intrinsic, which is divided into matter and form, and extrinsic, which is the efficient, and by a peculiar reason and as it were by antonomasia can be called extrinsic; for, although the final cause compared to the formal and material is also extrinsic, nevertheless compared to the efficient it is in a certain way intrinsic; for the relationship to the end is more intrinsic to each thing, and in some is even essential.

Whether the four members of cause are atomic

20. Of the fifth point few things can be said in this place until we treat of the individual causes, and therefore it must briefly be said that this is not a division into the ultimate notions of cause; for under any one of those members various divisions can be given. For of the material cause one is pure potency, another only potency in a certain respect. Which is not only a material division (so to speak) according to the entity which is the cause, but is also formal in the notion of material cause. For it is of its formal notion that it be potency, and therefore according to the diverse notion of receptive potency there will be a diverse notion of material cause; which diversity can also be attended to from the effects; for the former is the material cause of substance, but the latter of accidents. Whence the former can be called material cause simply, but the latter in a certain respect, taking these words not from the entities of such causes but from the relationship to the effects; for as regards entity the material cause of accidents can be being simply, or an integral substance; but the material cause of substance can only be being in a certain respect; yet as regards causation or the relationship of cause, the latter causes being simply, the former in a certain respect. Again the material cause of substance is divided into the matter of corruptible or incorruptible substances; but the material cause of accidents can be divided either into corporeal and spiritual, or into proximate or remote, or into that which in itself is an accident, or which is a substance, either partial or integral, of all of which I shall speak in the next disputations. And in a proportional way form can be divided into substantial and accidental, and each member is subdivided into various forms according to the variety of composite substances and accidents. Likewise of the efficient and final cause there are very many divisions, which cannot be briefly recounted here, but in the proper disputations.

21. Why cause has been divided by the principal division neither into the highest nor into the lowest members.—You will say: if cause can immediately be divided into fewer members and remotely into more, why did Aristotle hand down that four-membered division rather than others? The answer is that by the very fact that that division is intermediate between those extremes it was more apt for handing down a doctrinal division. Especially because those members have more distinct and better known notions and modes of causing. Add that Aristotle did not altogether omit, but sufficiently indicated, both the agreements of these causes among themselves and their divisions, as is evident from the places cited.

Of what kind the division given is

22. In the sixth point all authors, rather supposing than proving or disputing, teach that that division of cause is analogous, and for that cause say that cause in common was not defined by Aristotle. Yet they do not sufficiently declare the mode or notion of this analogy, nor can it be declared by us until the notions of the individual causes are exactly treated. And therefore let us now suppose that that opinion is true, from the authority of the common opinion and from this general reason, that those modes of causes are common to the causes of accidents and of substances, which cannot be causes univocally, because they do not give being univocally; whence neither can the notion of effect be univocal in accident and substance; but the more exact declaration of this analogy I remit to the aforesaid place.