Disputationes metaphysicae

1. The reason for doubting.—This question is general about all agents lacking intellect and will, to all of which it is common that they cannot refer or order their actions or means to an end. And hence the reason for doubting arises; for the proper causality of the end is not without this ordination, as those particles for the sake of which, and on account of which something is made, by which the causality of the end is commonly declared, sufficiently declare; and therefore it is difficult to find or declare final causality in the actions of these agents and in their effects, as it comes from them. On the contrary, however, is that these agents too act for the sake of an end, as Aristotle proves at length in II Phys., c. 7; but operation for the sake of an end cannot be understood without the causality of the end. And about brutes there is a special difficulty; for they are truly moved to love from some cognition of good; therefore in that effect and work there intervenes the metaphorical motion of the known good; therefore that pertains to true final causality. And experience confirms this; for we see the swallow so gather straws or effect something similar as is expedient for its end, and so of others.

The old opinion about natural agents

2. In this matter there was an ancient opinion of the old philosophers denying that the works of nature come from the intention of some end, but that they have so come about by chance, either from the concourse of atoms rashly so concurring, or from the necessity of matter, as Aristotle disputes in the cited place, II Phys., cc. 7 and 8, against Anaxagoras, Empedocles, Democritus and Epicurus. Which opinion is so absurd that it does not need refutation. It must be noted, however, that it is one thing to treat of the constitution of the whole universe, and of the action of universal nature for composing it and so ruling it that it can be conserved, another of the proper actions of the single natural agents. The former action or effecting is in truth not the action of some natural agent lacking intellect, but is the action of the supreme author of nature, who by His wisdom founded and moderates the whole nature of the universe; and therefore that action does not pertain to the present question, nor can it be doubted of it that it proceeded for the sake of an end intended by its author, and therefore from the causality of the end, according to the doctrine of the preceding section. And the very beauty of the universe and the wonderful consensus and ordination of its parts and of all causes most evidently teaches this. From which not only the holy Fathers but also the wiser philosophers understood that there is one author and governor of this universe, who constituted and ordered all things to an end intended by Himself, as we shall treat more at length below in demonstrating that God exists, and the Conimbricenses have indicated many things on this matter learnedly and briefly, bk. II Phys., c. 9, q. 1.

3. Here, then, we inquire only about the actions of natural causes, whether they are wholly particular, as fire, plants, etc., or in some way universal, as the heavens. Of which moreover it is certain and clear that they do not operate certain actions by chance or contingently, but that each natural agent from the propension of its proper nature has a definite operation, and mode of operating, and a certain terminus to which it tends through its operation. Which is also evident by experience, for a stone by its natural motion is always borne downward, fire always heats, from diverse seeds diverse living things are procreated, and some powers and organs are destined for this office, others for others; and single things have that form, situation, and all the rest necessary for operating in that proportion which is necessary for such actions or effects. Which can be seen in all natural things, and especially in living things and animals. And this was necessary for the fitting composition and government of the universe itself, for since it consists of various and contrary things, which also exercise various and sometimes contrary actions, if all things were not so constituted that each would orderly perform its offices, there would be the greatest confusion in the universe itself and the things themselves could by no means be conserved¹; but in order that harmony and order of this kind might arise from so many things, it was necessary that single things tend by their actions to destined ends or termini, from which the good of the whole universe would arise. Likewise for this reason we see natural motions regularly perfected in the same way, and rarely failing, and that not without some extrinsic impediment occurring. Likewise in their works natural things so behave as is expedient in order that they arrive at their connatural terminus, which terminus being attained they cease from operating. All these, then, are manifest signs that these natural agents operate not by chance and rashly, but by tending in a definite mode to some certain goal.

4. The error being rejected, in what the difficulty is placed.—Now there remains only the question (which in part seems able to pertain to the mode of speaking) whether by reason of this determination these agents are to be said to act for the sake of an end, and (what pertains more to us) whether their actions can be said to be properly caused by the final cause. For some simply deny each mode of speaking, because the agents themselves are not moved by the end, in which properly the causality of the end consists. Likewise, the end with respect to these actions does not behave as principle, but only as terminus; for the lower place with respect to the stone is not the principle of the motion by which it descends, but only the terminus; but the end, as we have often said, as it has only the notion of terminus, is not a cause, but as it is in some way a principle. But others think that those expressions are simply to be admitted, because Aristotle absolutely says that natural agents operate for the sake of an end, and says that the form is the end of natural generation, and signifies that it is properly a final cause. Likewise, because nature seems to exercise these its operations with the highest art and industry through means very proportioned to the end.

Resolution about the causality of the end in merely natural agents

5. Nevertheless, the proper mode of speaking in this matter is that the actions of these natural agents are for the sake of an end and are effects of the final cause. Not, however, as they precisely go forth from the natural agents themselves, but as they are at the same time from the first agent, which operates in all things and through all things. Or conversely (and it comes back almost to the same), as the proximate agents themselves underlie the direction and intention of the superior agent. And therefore the natural agents themselves are not so much said to operate for the sake of an end as to be directed to an end by a superior agent. So the wiser theologians and philosophers explained this matter, St. Thomas, q. 103, a. 1, and III Cont. Gent., c. 25, where he uses the common example of the arrow, which tends to a certain goal, yet does not direct itself to it, but is directed by the archer. Albert the same, in II Phys., c. 2; and there other philosophers, and Simplicius, text 78; and it is taken from Aristotle there, and I De Caelo, c. 4, text 32, where, while he conjoins God and nature, saying that they do nothing in vain, he sufficiently indicates that nature in acting for the sake of an end is subordinated to God. And in the same way, in bk. II De Partib. animal., c. 13, he says that nature does nothing in vain; and there he says that nature wills this or that for the sake of an end, which cannot be understood of nature except on account of its author. And in the same sense he says, IV De Generat. animal., c. 2: All things which are made by nature or art are by some reason. And hence too flowed that trite axiom, the work of nature is the work of an intelligence, as is found in Averroes, XII Metaph., comm. 18; and Themistius, I Phys., text 81, and I De Anim., text 23. Finally, therefore, Hippocrates, whom Galen imitates, bk. I De Usu part., calls natural agents learned and unlearned: unlearned in themselves, learned in the direction of the first cause.

6. And so it comes about that in these actions, as they are from natural agents, there is not proper final causality, but only relation to a certain terminus; but as they are from God, there is final causality in them as in the other external and transient actions of God. For the adequate principle of these actions is not only the proximate natural agent, except perhaps in a qualified sense, namely in such order; yet absolutely the chief is the first cause; and therefore in the adequate principle of such actions is included an intellectual cause intending their end.

7. Why natural things are affected with diverse dispositions.—Hence further Aristotle rightly concludes that the first root on account of which natural things have these dispositions, or these organs, or these parts and similar things, is not to be taken from matter alone, but from the end. For if matter is taken according to itself, it is indifferent and has no necessity of these dispositions or properties; but if it is supposed as already affected with these or those dispositions, these have already been introduced for the sake of some end or form, and the form itself needs them for its conservation or for some operation; but the operation itself again is either for the conservation of the species or of the individual itself, or at least for the communication of its perfection; for in these natural agents there are not operations which themselves are ends; for this is proper to intellectual things. And so every connection and connatural necessity which is per se in these natural things is taken from order to the end. Nor does it stand in the way that natural properties necessarily belong on account of intrinsic emanation from the form, because one relation is not repugnant to the other, but they have subordination among themselves, for that necessary emanation is reduced to the efficient cause, which is subordinated to the final; for nature gave to such form the power that such properties should emanate from it for this reason, because they are accommodated to the end for the sake of which is the thing which is constituted through such form. Thus, then, both in the constitution and formation of these things and in their action the concurrence of the final cause is found; but the proper intention of such end is not in the natural agents themselves, but in the first cause.

8. What necessity there is of asserting the connection of natural things and their direction to an end.—But it can seem to someone that this mode of acting for the sake of an end is devised without cause, and is beside the intention of Aristotle. For in the first place Aristotle, in XII Metaph., seems to think that God does not know these lower things, let alone care for them; and in the book On the World to Alexander he signifies that they do not think rightly of God who think that God is occupied in caring for these lower actions. Next, if, per impossibile, God did not concur to the actions of natural agents, but let them perform their motions independently, nevertheless a stone would descend downward, fire would generate what is like itself, and so of the rest; this is not, therefore, final causality, but mere natural necessity. And it is confirmed, for if natural agents acted from divine intention, they would never err in their actions, nor fail in attaining their termini; the consequent is against experience, since monsters are often generated, which are called sins of nature. The sequel is evident, because the divine intention can neither be frustrated nor err.

9. It is answered: of the mind of Aristotle it is already sufficiently established from what has been said, and we shall show more at length below that, according to his opinion, God has knowledge and providence of these singular and lower things; which he indicates not obscurely below, bk. XII, at the end, while he subjects the whole universe to God as to the supreme prince and leader. But to the first reason it is answered, first, that from that impossible hypothesis it follows that nature operates most orderly tending to an end without any direction or intention of the end, which per se is sufficiently absurd. For in the same way someone could argue that, although this world were not founded by another, if it were of itself as it now is, it would have a most fitting order without the causality of the end. This, however, does not prevent that in fact, just as it cannot be except as caused, so it cannot be except as caused by the end. So, then, we say that the motions and actions of natural things, just as they cannot be without the concurrence of some intellectual agent, so they cannot be without the causality of the end. I add next that, if per impossibile God did not concur per se and immediately to all the actions of natural agents, nevertheless they would have to be said to be mediately ordered to an end by the author of nature, who both gave natural agents such powers for the sake of such actions and willed the actions themselves to be for the sake of certain ends and generally for the sake of the good and conservation of the universe.

10. Many effects in nature of which no sufficient cause can be given besides the end intended by the first cause.—Hence finally I add that there are many motions or actions in these natural things of which no sufficient reason can be given from the private properties or inclinations of single things; for water ascends upward to fill a vacuum, of which the reason cannot be given from the peculiar nature and proper impetus of water, but from the end which is placed in the perfection of the whole universe, which must be intended by another superior agent. Similar is the case of the water of the sea, which so contains its impetus and swelling waves on the shore that it never covers the earth; namely for the safety of mixed bodies and living things, which end the supreme Governor of nature intends. From these, then, we understand that, when these natural things are moved or operate according to their proper and peculiar inclinations, since through them they also serve the advantages and conservation of the whole universe and of their species, or also of individuals and especially of man, in them too they operate from direction to an end, through subordination to a superior agent.

11. To the confirmation it is answered by simply denying the sequel; indeed rather Aristotle, II Phys., text 82, thence confirms that these natural agents act for the sake of an end, because, just as art intending an end sometimes does not attain it, so in the actions of nature, because they intend a certain end, thence follow monsters or sins of nature, because they cannot always attain their end on account of an impediment occurring². Otherwise, if nature did not tend to a certain end, there would be no monsters in nature, because it would no more stray from the goal by effecting a monster than by effecting anything else; for a monster properly is a defect of nature failing from its end. But what was objected about the intention of the author of nature does not stand in the way, because that intention is not always absolute and efficacious, or (to speak in the manner of the theologians) by the will of good pleasure or consequent, but by the general or antecedent will, which is as it were a conditional intention, which consists in this, that God wills the perfect effect to follow so far as it could follow according to the order of natural causes, with which, so far as concerns Himself, He wills to concur. But at the same time He either permits, or also sometimes wills and intends, monsters or sins of nature, either for the beauty and variety of the universe, or in order to let natural causes perform their motions and courses. And therefore He neither wills to concur in an extraordinary way with a cause impeded by another, nor yet to remove the impeding cause by peculiar care or providence, regularly speaking, although for the common good He sometimes does this, of which the theologians speak more at length, partly In I, dist. 45, partly In II, dist. 37; and St. Thomas, I, q. 22, and q. 105; and Augustine can be read, XVI De Civit., c. 8, and bk. LXXXIII Questions, q. 24.

How brute animals operate for the sake of an end

12. It remains that we say a few things about brute animals, for in them a certain greater participation of final causality appears. First indeed, because they are metaphorically allured by the good fitting to them and known, and so tend to it through an act elicited by themselves and caused by that metaphorical motion; that motion, then, is some real causality, and none other than final. Next, in order to attain that fitting object which they have desired, they desire also certain means known by themselves with so great industry and prudence that they seem plainly both to know their utility for the end and to desire them on account of it. Of which sagacity and industry of animals both the philosophers write much,³ and daily experience makes it sufficiently established to us. Which so moved some philosophers that they thought brutes use reason, although weaker and more imperfect than men. Which opinion is commonly reported from Porphyry, bk. III On Abstinence. It is, however, foreign not only to the doctrine of our faith, but also to all reason and the common sense of men; for the rational power, as Aristotle said, IX Metaph., is able for opposites, for by means of discourse in things to be done it uses now this means, afterwards another; but beasts do not so operate, but always in the same way, which is a sufficient sign that they are led not by reason but by the impulse of nature. Add that, if the souls of brutes were rational, they would also be immortal.

13. It is absurd that brutes truly know or vitally desire nothing.—But others, in order to avoid this drawback, fell into another extreme error, denying that brutes truly know or desire anything by elicited appetite, but are borne only by natural weight, as a stone, or moved and attracted from without, as iron is drawn by the magnet. But this is equally absurd, and against evident experience, indeed also against divine Scripture. Nevertheless, against these two errors one must treat more at length in the science of the soul.

14. Brutes do not formally know the notion of end.—As regards the present, then, it must be said that brutes do not formally know the notion of end or of means, because they cannot compare one with another; hence neither in the end itself do they know the proper notion of fittingness on account of which it is per se lovable, indeed neither do they discern between the object inasmuch as it is fitting per se or for the sake of another, because this whole requires great discretion of reason. In some way, however, they know and apprehend some thing or motion as fitting to themselves, and by natural instinct judge that such object is to be desired, pursued or fled by them.⁴ Which natural instinct is nothing else than a certain act of the phantasy or estimative power flowing from it by natural necessity, the phantasm of such thing being posited; by which act practically (to speak in human manner) the brute judges that this is to be avoided, or pursued, or desired by it, although it cannot discern the notion of fittingness or unfittingness. But this natural judgement being posited, the appetite too naturally follows it.

15. What causality of the end brutes participate.—From which it comes about, first, that the causality of the end is in some way participated by brutes, as the argument made convinces, because that elicited appetition is without doubt caused by the metaphorical objective motion of the fitting good, which cannot be brought back to another genus of causality. Nevertheless it must be added that that causality is so imperfect in that genus that it is rather as it were a material motion of the end than a formal one, as St. Thomas signified, I-II, q. 1, a. 2, and q. 6, a. 2. And the reason is that they do not know the formal notion of fittingness or utility; therefore they are not so moved that they can order one thing to another, nor yet formally desire something as lovable for its own sake; therefore they do not tend formally to the end as end, nor to the means as means, nor to the end for its own sake and to the means for the sake of the end, but, as far as concerns their mode of operating, they tend equally to both, and therefore they are deservedly said to operate materially rather than formally for the sake of an end. Wherefore, as regards formal relation to the end, the same judgement is to be passed of the actions of brutes as of other natural agents. And the same judgement holds of the sensitive appetite of man, if it is considered per se alone and not as it underlies the motion of the will or of reason, of which elsewhere.