Disputationes metaphysicae

1. The reason for proposing the question.—I propose this question chiefly on account of Aristotle in the prooemium of the Metaphysics, in order that on its occasion we may declare some things which remain to be declared from that prooemium, lest we either pass over them altogether or find it necessary to return to them again. The exposition of this doubt also contributes to commending more fully the dignity of this doctrine, from the fact that it is most of all conformed to the nature of man as he is rational, or rather is his supreme natural perfection.

2. Aristotle, then, in Metaphysics I, cc. 1 and 2, seems directly to intend the affirmative part of this doubt, namely, that the natural appetite of man is most of all drawn to metaphysics. In order to persuade of which he premises that axiom: Every man naturally desires to know.

What the sense of that pronouncement is: Every man naturally desires to know

3. What innate appetite is.—What elicitive appetite is.—Concerning which it is necessary first of all to set out the sense of Aristotle, then the truth of the proposition. Three terms, then, are to be declared in that proposition: the first is to desire or to long for. Concerning which, first, the common distinction of a twofold appetite, innate and elicitive, is to be supposed. The former is called appetite improperly and metaphorically; properly, however, it is nothing other than the natural propensity which each thing has toward some good; which inclination in passive powers is nothing other than the natural capacity and proportion with its perfection, but in active powers is the natural faculty of acting itself. And so in all these appetite adds nothing beyond the nature of the thing itself, or the proximate faculty, by reason of which such an appetite belongs to the thing. Nor in this appetite can first act and second act be distinguished, because to desire in this way is not to do something, but only to have such an innate propensity, such as heaviness has toward the centre, even if it does nothing. Elicitive appetite is properly appetite, because it is borne to the good as good, and can desire it by its proper act. Hence there are two things in this appetite (we speak of creatures): one is the faculty of desiring, the other the desiring itself. The first has now retained the name of appetite, which is divided into sensitive and rational; and this appetite as such is also innate, if we speak of the innate in general, because it has been given with nature itself, and has a natural propensity toward its object and its act. But because it is so innate that it is also elicitive of the actual desiring by which it tends to the good formally and in so far as it is good, and so is most properly appetite, it is therefore co-distinguished from the purely innate and metaphorical appetite; for in this way the former division is to be taken. The second, that is, the act of desiring, which is properly called desiring, or elicited appetite, is nothing other than the act elicited by the eliciting appetite, which loves or desires the good; and this appetite is never innate, at least in us, of whom we are treating at present; sometimes, however, it is natural, as I shall declare more professedly below.

4. In how many ways natural is said.—The second term, then, to be set out was naturally; for natural appetite is said in many ways; for sometimes that is called natural which has been given by nature itself, and has not been effected by the proper, for example, action or effecting of the man himself. And in this way every innate appetite is natural, and the elicitive appetite itself too; not, however, the elicited appetite or act, as is sufficiently evident from the exposition of the terms given. Sometimes, however, that is called natural which comes about necessarily from the intrinsic propensity of nature, even if absolutely and in itself it has not been given by nature, but made by the one desiring; and in this way the appetite which is hunger or thirst is natural to man when food or drink is lacking; by which reason an elicited appetite can be natural, and in the sensitive appetite it is always so of itself; but in the will, although such an appetite is sometimes natural, it is not always so, because the will is free. I omit that natural is sometimes taken as it is distinguished from supernatural, in which sense among natural philosophers, or when proceeding from the light of nature alone, as we are now speaking, every appetite is natural, for the supernatural mode of desiring, which comes about through grace, cannot be investigated by natural reason. Sometimes also natural is taken as it is opposed to violent, as is frequent in philosophy. And in these two ways too an elicited appetite, even if it is free, can nevertheless be natural, as is self-evident. Indeed, sometimes an elicited appetite is called natural by the very fact that it is consonant with nature, and it is opposed to what is preternatural as dissonant with nature, even if it is not violent; in which way the appetite for virtue is natural, but that for vice not at all. Whence it finally comes about that that appetite is much more called natural to which the very propensity of nature brings necessity; and therefore a necessary appetite, even though elicited, can rightly be called natural.

5. A twofold necessity of this appetite, however, is wont to be distinguished, namely, as regards exercise and as regards specification. The former is when the vital appetite elicits or exercises the act of desiring of necessity; which necessity is easily found in the sensitive appetite; in the rational, however, it is not found in this life, but only in the blessed and supernatural life, which does not pertain to our consideration. The latter consists in this, that, although the will does not exercise the act of desiring of necessity, yet, if it exercises it, it necessarily desires and does not shun such an object; and such an act is called necessary as regards species, not as regards exercise; and according to that necessity it is called natural, and departs from an act free on every side, namely as regards exercise and specification, in the way in which the will desires the good in common. From these things, then, the ambiguity of that word remains sufficiently clear.

6. In how many ways science is said.—The third word is science or to know, which is taken indefinitely by Aristotle; and it can be taken generally for any knowledge or understanding of truth whatever, but especially for that which is perfect and has the proper notion of science, as to know is said to be to know a thing through its cause with evidence and certitude. And of science taken in this way too we can speak either indefinitely, or abstractly, or distributively of all the sciences, or singularly of some one; which modes of speaking of science differ not a little among themselves.

7. Man desires all the sciences.—Beginning, then, from this last term, it is certain that Aristotle in that general dogma does not speak of some singular science, as is evident both from his words, and from the proof, which is general, and finally from his intention; for he takes this general principle in order to descend thence to this science in particular. And this reason further concludes that, although Aristotle’s words are indefinite, nevertheless, since they are doctrinal, they are equivalent to universal ones, so that the sense is that all men naturally desire any science whatever: both because this appetite does not arise from the peculiar notion of some science as it is such, but from the notion of science as such; and also because otherwise one would not proceed sufficiently efficaciously in that discourse from indefinite speech to singular. This, then, is the mind of Aristotle; and that that opinion is true in that sense will easily be evident from what is to be said.

8. With innate appetite.—Again, many expositors here, especially Scotus and his followers, think that Aristotle speaks of innate appetite; nor does St. Thomas shrink from that opinion; whence Javellus and Flandria follow it. Nor is there doubt that in that sense the proposition is most true, which St. Thomas confirms by various reasons. The sum of them is that every thing naturally desires its perfection, operation and happiness; but science is compared to man in all these ways; for it is a great perfection of his, and his operation, and his happiness consists in it. In which reason the first two members are common to all the sciences, but the third is proper to this one, as we shall say. Hence I also think that Aristotle did not exclude this sense, but rather supposed it. But that he spoke in that sense alone seems neither necessary nor true. Which can be gathered from the propriety of his words; for from the delight and love of the senses he gathers the appetite for science; but he speaks openly of the love of the senses through an elicited act; for love properly signifies this, and below he similarly says that we prefer the sense of sight to the others, namely in elicited love. And although it could be said that it is true that Aristotle in that reason speaks of the elicited act, and from it gathers natural appetite, certainly that inference would not be good unless he supposed that that elicited love is also in some way natural, because natural appetite cannot be gathered from any elicited appetite whatever; for sometimes by an act of the will we desire things which are repugnant to nature itself, such as, for example, death; therefore, if Aristotle gathers natural appetite from elicited appetite, he supposes that the elicited one too is natural; and if the elicited love of the senses is natural, much more the love of science.

9. With elicited appetite too.—It must be said, therefore, that man loves science with elicited appetite too. The reasons indicated from St. Thomas prove this; for they proceed equally of elicited appetite and of the weight of nature, because man also by this appetite naturally desires his perfection, operation and happiness; but science is the most perfect operation of man, and is either happiness itself, or most necessary for happiness and the advantage of this life. For if it is contemplative science, happiness consists in its most perfect operation, as is said in Ethics X, c. 6; and the other speculative sciences serve that higher one, and in all there is a certain great delight; for to contemplate is best, Metaphysics XII, text 39. The practical sciences, however, are necessary, or very useful, for the advantages of this life too.

The doctrine of Aristotle about the love of sight and of the other senses is explained

10. Moreover, the discourse of Aristotle taken from the love of the senses, and especially of sight, is excellent for confirming the same thing. Aristotle takes two things in that discourse: the first is that in the love of the senses we prefer sight; the second, that the cause of this is that it serves science most of all. From which he infers a third, namely, that the love of science is greater and more natural than that of sight itself and the other senses. Which inference seems self-evident, and founded on that principle: That on account of which each thing is such, is itself more so. The first proposition assumed, however, is first of all to be understood with prescission, in order that the comparison may be made rightly; for touch can be found without sight, but not conversely, because touch is the first of all the senses and the foundation of the others. Whence, touch being destroyed, sight cannot naturally remain, because neither is life preserved without touch, De Anima III, c. 12, and De Sensu et Sensato, c. 1. In so far, therefore, as sight in a certain way includes touch, sight will be more desirable than touch alone; and in the contrary sense, in so far as the loss of touch includes the loss of sight, and not conversely, touch is preferred to sight, because a man will rather choose the conservation of touch than of sight, if at the loss of touch sight must necessarily be lost. But this comparison understood in this way is of no moment, because the individual senses are not compared among themselves, but two to one which is included in them; the comparison, therefore, is to be made precisely in what each contributes per se.

11. Sight and hearing are compared.—Next it is to be observed that Aristotle here indicates a twofold love of the senses. One is on account of usefulness; the other on account of knowledge. The former is most self-evident, and under usefulness can be comprehended every advantage of the body, pertaining either to its conservation, or to pleasure, or to the other operations of human life. The latter love is most proper to man, and in order to this love sight is chiefly compared here with the other senses and preferred to them. Which Aristotle proves by experience, because (he says) even when we are about to do nothing, we prefer sight itself to the others. But he gives the a priori reason, and the one which pertains most to the present matter, in the other proposition. Concerning which it is to be noted, thirdly, that there are two modes of acquiring science, namely, instruction and discovery. For the former mode hearing is most useful, as is self-evident, because words are signs of concepts; but hearing alone perceives words, and although it does not itself perceive their signification, but the mind does, it is enough that it is the proper organ by means of which such a sign reaches the mind. This excess, however, is both per accidens and very small. Per accidens indeed, because the mode of acquiring science through instruction is as it were per accidens; for it both supposes the other, speaking according to the natures of things, and is only for supplying the imperfection or negligence of men in devoting themselves to finding the sciences. But I call the excess very small, because sight too serves very much for instruction; for writings too are signs of concepts, and they are perceived by sight; whence many more things seem to be learned by reading, which is done by sight, than by hearing.¹ There is, however, this difference, that almost the whole usefulness of writing can also be perceived by hearing, but not conversely; for that energy, force and clarity which is in the voice for expressing one’s own concepts cannot be supplied by writing alone or by sight; whence we read that some lacking sight were most learned, partly by hearing only the writings of others, partly also by explanations or teachings proposed to them by the living voice; but that someone altogether deaf turned out most learned, I do not remember having read, and I scarcely think it can happen. These senses, therefore, are not compared here by Aristotle as regards this function, but as regards the mode of acquiring science through discovery. In which there is no doubt that sight and touch surpass both hearing and the other senses, which is so well known that it does not need proof; it only remains to say briefly about the comparison of sight and touch between themselves.

12. Comparison of sight with touch.—It is to be noticed, therefore, fourthly, that it is one thing to speak of the sign (so to speak) of a better faculty and greater aptitude for acquiring science, another of the more apt instrument for finding science; for touch surpasses sight by the former reason, because touch is a universal sense on the side of the subject, for it is diffused through the whole body, and is a sign of the best and most temperate complexion; whence that saying: Those of soft flesh are apt in mind; concerning which more fully in De Anima II, text 24. But sight per se, and as an instrument for science, surpasses touch in many ways. First, in the breadth of its object; for it perceives more differences, as Aristotle said here, and ranges over heavenly and earthly things, and knows the motions, actions and figures of things more perspicaciously than any other sense; but these are as it were the first signs and indications which we use for knowing things. Secondly, it perceives more quickly than the other senses, although it extends itself even to things most distant; and the cause is that it completes its operation in a purer and more immaterial mode, and without material alteration. Thirdly, it impresses what it perceives on the phantasy more vehemently, which is evident by experience; for such things inhere more tenaciously in memory, and occur more easily afterwards. The cause, however, seems to be that its operation, as it is more spiritual, so is performed with greater force and effort of the soul, and with greater cooperation of the phantasy itself. Fourthly, the experience of sight seems more certain than the experience of touch, speaking per se; for although Aristotle, History of Animals I, c. 15, says that touch in man is most exquisite, he there does not compare the senses of man among themselves and with respect to man himself, but with the senses of other animals; and in this way he says that man surpasses the other animals in touch and taste, although in the other senses he is surpassed by many, at least in many conditions of sensing, as by the eagle in the perspicacity and strength of sight; he does not, however, say that the touch of man surpasses his sight in certitude. Rather, in Problems XXXI, q. 18,² he says that touch rivals sight. And so each of these senses has its certitude in order to its proper adequate object; but sometimes it fails with respect to the common sensibles from insufficient application; and perhaps because sight senses from afar and touch does not, it therefore happens more easily that the object of sight is unduly applied and sight is deceived; if, however, other things are equal as regards the application of the object and the disposition of the power, deception does not happen more in sight than in touch. And on the other side sight, on account of its immateriality, perceives its object more acutely, and on this side is more certain; and therefore it is wont more frequently to be used for receiving certitude about sensible things. For these causes, therefore, sight is simply more useful for the sciences, and for this reason it is naturally loved more; it is a sign, therefore, as Aristotle concludes, that science itself too is naturally loved by man.

Of the elicited appetite for science

13. But in what sense it is to be understood that man naturally desires science with elicited appetite remains to be explained. For this cannot be taken in the sense that man of necessity always exercises love or desire of science whenever he thinks of it, nor that he cannot despise it and be unwilling to seek it; for each is against experience; this elicited appetite, therefore, cannot be natural as altogether necessary, either as regards exercise or as regards specification. First, then, it is certain that this appetite is rightly called natural because it is very consonant with the nature of man and with his natural inclination, in so far as he is man. Whence Cicero rightly says, De Finibus II: Nature (he says) has implanted in man the desire of finding the truth. Secondly, it is called natural because it is in some way necessary as regards specification; because, although man can neglect science, or be unwilling to seek it as regards the efficacious appetite of seeking it, this can happen only on account of extrinsic causes or impediments which are adjoined to science by accident, namely on account of the labour and difficulty which the study of science has, or because it impedes the pursuit of other things which man either needs or is attached to, or for other similar causes; whence those of ruder talent seem to desire science less on account of the difficulty, which Aristotle even called impossibility, Politics V,³ last chapter. But of itself science cannot displease, and so, impediments being set aside, it is loved by a certain necessity, at least as regards specification. And this indeed is most of all true of science in common in so far as it is science; yet it is also in its own way true of any science in particular, if in it the knowledge of truth in such a matter is regarded per se; for that perfection is always per se desirable to man. And if it happens that a man does not love one science in order to attend to another, this too is reduced to the extrinsic impediments of which we have spoken; for because man cannot acquire both sciences, and by the study of one would be impeded from the perfect pursuit of the other, he therefore omits the former in order to obtain the latter. And in this way certain men from their individual and proper complexion are more attached to one science than to another; per se, however, and impediments being set aside, or (what is the same) if one did not impede the other, we would naturally desire all the sciences, nor would we despise one by reason of another.

14. Inference.—And hence it is also easily evident what this appetite in man is; for if the discussion is of elicited appetite, it is evident that it is an act of the will, either efficacious, or at least inefficacious and by simple complacency, which is most natural, and remains even in those who do not efficaciously intend or choose to devote themselves to science. But if the discussion is of the natural weight, it can be considered as terminated immediately at science itself, and thus it is nothing other than the intellect itself and its capacity, by which it regards science as its proper perfection. For just as in prime matter the appetite for form is not something other than the matter itself and its natural capacity, and similarly in every other power the appetite for its act is not something added to the power itself, but its natural constitution and aptitude, so the appetite for science stands in the intellect. But if the weight of nature is considered as it is terminated at science by means of an elicited appetite, it is nothing other than the will of man, which in this way is naturally inclined to all the perfections of man; for the will does not desire to have science, but it naturally desires to will science for man or for the intellect; and in this way we say that this weight of the will is terminated at science by means of an elicited act.

That the natural appetite for knowing is greatest toward the speculative sciences

15. From these things, then, that general axiom remains sufficiently explained, that a natural appetite for science is innate in man; under this principle, however, it is to be taken that this appetite is greatest toward the speculative sciences, which are sought only for the sake of knowing the truth. Aristotle seems tacitly to have intended this in the whole discourse of that first chapter of this prooemium. To explain which he distinguishes all these things, and their order among themselves, namely, sense, memory, experience, art, science, which he tacitly distinguishes into that which is sought for the sake of work or usefulness and that which is sought for its own sake, and in the last place he adjoins wisdom.

16. Some sayings of Aristotle in the prooemium are explained.—He says, then, first of all, that sense has been given by nature to all animals; he does not, however, explain what it is, because this does not pertain to the present matter; nor does he say that every sense has been communicated to all animals, but sense indefinitely; and he intends only to suppose that this is the most imperfect grade of knowledge. Secondly, he adds that brute animals sometimes have, besides sense, memory, and a certain natural prudence as it were; and that some extend to this, that they are also teachable, but participate little or nothing of experience. Where notice that by the name of sense Aristotle understands also the sensitive knowledge which comes about only in the presence of the object, whether through the internal senses, or through the interior common sense or phantasy; for whatever is necessary for sensing in the presence of the object he comprehends under the name of sense; but in all something of phantasy or imagination is necessary even for sensing externally; and therefore, just as to sense, so also to use imagination is common to all brutes. Memory, however, adds an interior power of preserving species and using them in the absence of the objects, so that in this way one can remember those things which one perceived by sense, even when one does not have them present according to the external senses. This faculty, then, Aristotle says certain animals have, but not all; he does not, however, declare which are these or those.

17. It is commonly judged, however, that those animals have memory which can properly and perfectly be moved from place to distant place, whether by progressive motion over the earth, or by flying through the air, or by swimming in the water; for memory seems to have been given to animals for this end, that they may be able to be moved to a distant place, either fleeing harmful things or seeking useful things which they have in some way experienced. Nor does it matter that a brute can sometimes be moved to a distant place not from some memory, as is evident in the newly born; because either it is then moved by an object somewhat distant, or it wanders, and roams as it were by chance.

18. Whether flies have memory.—But what Aristotle says here of flies, that they do not have memory even though they are moved to distant places, is quite uncertain; for the sign by which Aristotle is moved to assert this, namely, that flies, when struck and driven from a place, immediately return importunately, is insufficient, since this can rather happen from the memory of the delight which they take there, and from vehement appetite, or because that object is always in some way present through sight or smell, and therefore moves more vehemently. Only of those imperfect animals, then, which possess only the sense of touch, or also of taste, can it certainly be affirmed that they lack memory, because they have no sign or effect of it, nor use for it.

19. What kind of prudence there is in brutes.—But what Aristotle says, that certain brutes with memory have prudence, is to be understood not properly but by transference; for they do not use discourse, nor acquire a habit by which to judge about things to be done; but because by natural instinct they often so operate as is expedient to such a nature here and now, and so provide for the future as if they truly reasoned, they are therefore called prudent by metaphor. You will say: therefore this prudence of brutes is nothing other than the instinct of nature; but all animals have this instinct accommodated to themselves, even those which lack memory; why, then, does Aristotle attribute this peculiarly to certain brutes? To this Javellus, Book I, q. 7, seems to distinguish nothing between natural instinct and the prudence of brutes, and to concede all that the reason given seems to prove, namely, that this prudence is in all brutes; and he ascribes this opinion to St. Thomas. But, although perhaps it is a question about a name, that manner of speaking is nevertheless foreign to the mind of Aristotle, as the reason given shows; and it is beyond the notion of metaphor; for some animals are so stupid that they cannot be called prudent even by metaphor; not only of all those which lack memory, but perhaps also of those which are endowed with memory. Whence Aristotle said not that all, but that certain ones with memory have prudence. Others, taking this metaphor with too much rigour, say that only those animals are called prudent which operate from the memory of the past, either to provide for the future, or as it were to choose some means. So Fonseca holds here, reporting others. But this limitation seems excessive; for so much propriety is not necessary in metaphors. For when Christ said: Be ye prudent as serpents, he said it not on account of operation with memory of the past, but on account of natural sagacity, by which the serpent guards its head, as the Saints explain. And the ant is judged prudent when it gathers grain for the winter, even if it does this without memory, as when it first operates thus. This prudence of brutes, therefore, is the special sagacity of certain ones, which are so ruled by the instinct of nature that they seem to imitate the reason and prudence of man, as Aristotle said in general, History of Animals I, c. 5, and in particular of many, Book IX, c. 6 and following; and in c. 7 he says that this kind of prudence is found more frequently in the smaller kind of animals than in the larger; and there he recounts many things which he says pertain to this prudence, not because they proceed from the memory of past things, but because they proceed from a certain natural ingenuity as it were, by which they imitate the reason of man. And in this way this natural prudence is not found in all; yet the brutes which are endowed with it always have memory too, not because this prudence is always founded in memory, but because these animals are always so perfect as to participate memory. We can also add that these very animals, prudent by their nature, become more prudent through the memory of the things which they have experienced. And in this way it could be said in favour of the second opinion that natural sagacity itself most of all deserves the name of prudence when it has been as it were cultivated and perfected by the memory of things; but these things are enough said about the use of the word.

20. Which animals are teachable.—Whether bees hear.—Aristotle adds that certain animals not only have memory but are also teachable, but others not at all. Of this latter kind he says are those which, although they have memory, lack hearing, because hearing is the sense of instruction; and although sight too helps toward instruction, and we sometimes see certain brutes, such as puppies, taught and instructed even by certain external signs, nevertheless this never happens without some cooperation of hearing, by which they are aroused and called in order to perceive the signs. Aristotle, however, gives an example in bees, about which there is nevertheless a great controversy whether they hear, as Aristotle himself teaches, History of Animals IX, c. 40; and Pliny, Book XI, c. 20, affirms that they hear, which absolutely seems more probable, considering the signs and experiences which these authors report. For they teach that bees are soothed and attracted by certain sounds; likewise that they utter certain sounds among themselves when they wish to take flight, or are aroused from sleep, or are called together to sleep. Whence Albert here uses a certain probable distinction of hearing; for there is hearing of sound as such, or of voice as it is articulated sound; and he says that bees have hearing in the former way, but not in the latter; and that this latter mode is necessary for instruction.

21. Of the former kind of animals, namely the teachable ones, nothing occurs to be noted, except that this instruction too is to be understood metaphorically, like prudence; for those animals are said to be capable of instruction which by a certain use grow accustomed either to approach when they are called by a certain name, or to gather together when they hear such a sound or voice, or to flee when they perceive another sign. Whence some are taught to dance after the human manner, others to speak, and the like. All of which are done by these by natural instinct alone, memory and experience of such a sign or voice being supposed. Aristotle says, however, that all animals which have hearing are teachable. Which is perhaps true; it would, however, be difficult to believe that this is evident by experience in all animals; and without experiment I do not see how it could be affirmed of all both winged and aquatic animals. It can more easily be said that all animals which are teachable have hearing, and perhaps also sight, memory and metaphorical prudence or sagacity.

22. Aristotle concludes, therefore, that brutes live by imaginations and memory, and participate little of experience; indicating three grades, of which the posterior includes the prior, whence the prior are understood with the exclusion of the posterior. For imperfect animals live only by imperfect imagination, which they have together with the sense of touch or also of taste; others, more perfect, have memory alone with imagination; others, however, which are more capable of instruction than these, are said to participate a certain imperfect experience, since by use and custom they grow accustomed, as it were by a certain experiment; but why that experience is called imperfect we shall declare more fully immediately. But he says that men live by art and reason, which he declares in the rest of the chapter in order to arrive at his purpose. And rightly does he join those two, because neither seems to suffice without the other, at least for the perfect governance of man; for reason, which is natural, does not suffice unless it is cultivated by art; but art always needs the use of reason and attentive consideration in order to be applied to the work.

23. Experience is concerned only with the singular.—Experience properly so called is peculiar to man.—Thirdly, then, he says that in men experience is generated from memory: For many recollections of the same thing (he says) complete the force of one experience. In which place the occasion offered itself of declaring at length what experience is, and whether it pertains to sense or to intellect; likewise whether it is a judicative habit or an apprehensive one, and how it is generated, or to what it inclines. But because these things pertain rather to the science of the soul, and are touched upon here by Aristotle only in passing, it is to be noticed briefly that Aristotle here plainly teaches that experience is not concerned with the universal but with the singular; for thus he says: To have found that this helped Callias, suffering from this disease, and likewise Socrates, and in the same way many one by one, belongs to experience; but that it helped all those who suffer from a certain disease, this now belongs to art; and below he proves that experience is more useful for actions than science or art alone, because actions are concerned with singulars. The universal collection from singulars, therefore, does not pertain to experiment, and much less universal assent, but only a firm and prompt judgement about singulars. For experience taken broadly can be said of any perception of one singular, in which way someone can be said to have experienced that wine inebriates, even if he has undergone it only once, or seen it in another; but since, as Hippocrates said, experiment is deceptive, it is not properly taken for the knowledge of one singular only, but of many singulars, as Aristotle said. Indeed, it is not even enough for proper and perfect experience to experience the same effect often; for even brute animals can do this, of whom Aristotle said that they participate little of experience, because they have only the simple memory of those singulars which they perceived by sense; but for perfect experience there is further required a certain comparison of the same singulars among themselves, which is proper to man; and therefore Aristotle said that experience comes to man from memory, because many recollections of the same thing complete experience. Of the same thing, he says, not individual and singular, so that it would suffice for experience to remember often one and the same singular effect perceived by sense; for this repetition will produce a readier memory of such an effect, but not experience. He understands, therefore, of the same according to likeness and agreement of circumstances; and for this is required a comparison of singulars through recollection, namely, that such a medicine helped Peter suffering from this disease, and Paul similarly; for if there is not sufficient likeness, it will often seem to be experience, and in truth will not be. Whence it comes about that experiment is often deceptive. In this way, then, experience is proper to man, which, although it begins in sense, is completed by the mind and reason, as has been declared. Whence it does not consist in apprehensive knowledge, but in judicative, from which a certain ability is generated, by which man is rendered prompt for judging that this effect is wont to come forth from such a cause; which ability is perhaps nothing other than the memory of such singular effects, not in any way whatever, but as they have been compared among themselves and found similar, and are discerned to have emanated with those circumstances from the same or a similar cause. And let these things now suffice about experience, as the opportunity of this place allows.

How much experience serves art and science

24. Fourthly, Aristotle adds that art is generated through experience, and brings a more perfect knowledge than experience, even though without experience it is less sufficient for action. Where it is first necessary to notice that Aristotle here uses the names of science and art indifferently, as is evident from the context; and this because, although elsewhere they are distinct virtues, nevertheless according to a certain notion art is a certain science, or at least, as regards the present matter, the reason is the same concerning it and concerning science. Next it is necessary to notice that science or art is twofold: one they call of the fact, which only demonstrates that this is so; the other of the reasoned fact, which gives the cause. Of the former it is easily understood that it is generated through experience, because it only gathers from effects perceived by experiment that a thing is such, or has such a property. But Aristotle here speaks not of this science, but of the perfect science of the reasoned fact, as is manifestly evident; for when he had said that craftsmen are wiser than those who have the power of experience of things, he gives the reason: because the former know the cause, the latter not; therefore by art and science he understands that which attains and teaches the cause of the thing. And although he declares by many words and signs that craftsmen are preferred to those operating from mere custom or from experience, nevertheless all tends to this, that craftsmen know the reasoned fact and the cause of the thing. When, therefore, he says that art is generated by experience, he understands it of architectonic art and of the reasoned fact.

25. Which, however, is difficult, because human experiment is deceptive, as I said from Hippocrates; and although we grant that it is sometimes certain with the certitude of sense, that certitude nevertheless seems less than that which is required for science; especially because experiment is not universal, or about absolutely all singulars, but science is simply universal, and embraces even those singulars which have not fallen under experience. And although it is sometimes permitted from the things we experience to gather the same about singulars which have not fallen under experience, this collection nevertheless seems very weak, and at most will suffice for science of the fact, but not of the reasoned fact. Again, there occurred here the difficulty whether that proposition of Aristotle, that art is generated from experience, is only indefinite, as it sounds, or is to be taken as doctrinal and universal, so that it never happens that science or art is generated in us otherwise.

26. How science of the reasoned fact is caused by experience.—To the former part the answer is that the argument concludes that experience cannot be the proper and per se cause of art, or of a priori science, but is an occasion, or a certain necessary condition, by which the way is prepared for acquiring science. Which will easily be understood by noticing that two things are required per se in science, namely, the truth which is known and demonstrated, which is called the conclusion, and the principles through which it is known and demonstrated. The science of the conclusion, therefore, depends per se only on the principles; for, since it is a priori science, as we said, the middle term from which it is deduced per se is not experience, but the cause of the very effect which we experience; whence, if the principles which contain the cause of the conclusion could be known or understood clearly without experience, the science of the conclusion would in no way depend on experience. But the evident knowledge of the principles, which is proper to them, arises not from some middle term, but immediately from the natural light itself, the signification or notion of the extremes being known. We are dealing, however, with first and immediate principles; for if they are mediate, they will be demonstrated conclusions, about which the reason will be the same as about all other truths which are known a priori. Therefore neither are immediate principles known per se through experience as through their proper middle term; for in this way they would not be known as principles, but as conclusions demonstrated a posteriori, and known through science of the fact; but as such they could not be sufficient to generate science of the reasoned fact of the conclusion, because a cause cannot produce an effect more noble than itself. It remains, therefore, that experience is required for science only in order that our intellect may be led by the hand through it to understanding exactly the notions of the simple terms; which being understood, the intellect by its natural light sees clearly their immediate connection among themselves, which is the first and only reason for assenting to them.

27. Whether science can be generated without experience.—The other part of the difficulty is more extensive, but has its proper place in Posterior Analytics I, cc. 14 and 18; and therefore I shall briefly set forth what I think. For some⁴ think absolutely and without any restriction or distinction that experience most properly taken is necessary for science or art on the side of the judgement of the principles, so that the experimental knowledge of one or another singular never suffices, but it is necessary to experience many things and compare them among themselves, and find them all uniform and without difference. For before the intellect applies all this diligence it cannot assent with all natural certitude, as is necessary in first principles, because, since the very light of our intellect is weak and imperfect, unless it is helped by experience it can easily go astray; just as, conversely, experience itself too is of itself deceptive, unless the intellect keeps watch with its light to behold in themselves the notions of things and the connection of the terms. And this opinion is thought to be that of Aristotle in various places, namely, Prior Analytics I, c. 31, and Book II, c. 23, and Posterior Analytics I, c. 14, and Posterior Analytics II, last chapter, where the ancient interpreters seem to think so. Nevertheless, if the discussion is of experience properly so called, it seems to me that a distinction must be used, both in the principles themselves and in the mode of acquiring science. I said, if the discussion is of proper experience, because, if one deals generally with any sensible knowledge necessary for the apprehension and understanding of the terms, it is clear that this is necessary for the knowledge of the principles, because all our knowledge begins from sense; but this is not properly experience, which, as is evident from what has been said, consists in judgement or in a judicative habit; and of this without doubt Aristotle spoke. Speaking of this, then, a distinction must be used: for the principles are not all equal. For there is first of all one or another most general and most known, namely: Anything whatever either is or is not; It is impossible for the same thing at the same time to be and not to be; and for knowing these no experience is required, but only the apprehension, understanding or explanation of the terms; indeed, these principles can scarcely be reduced to positive experience; for although of any singular whatever we can experience that it is, nevertheless that it does not at that time lack existence we cannot experience positively by an experiment distinct from that by which it is seen to be, but it is perceived by understanding alone, the terms being explained. And this seems so self-evident that it does not need other proof. We can, however, use an example for greater explanation; for if we wish to induce a rustic man, who through ignorance of the terms does not know how to assent to those principles, to assent to them, we shall certainly use no new experience, but shall only try so to explain the terms that he may understand that the thing which he sees to be cannot absolutely not be.

28. Besides these most known principles, however, concerning which there can scarcely (as I think) be controversy that they do not require proper experience, there are others also very universal and common to almost all the sciences, such as: Whatever things are the same as one third thing are the same as each other, and Every whole is greater than its part, and If from equals you take equals, the remainders are equal. And concerning these it is necessary to distinguish when the knowledge of such principles is acquired by discovery, or by instruction. For in this latter mode I think that experience properly taken is not necessary, but, that being supposed which suffices for distinct knowledge of the terms, and the notions of the terms being sufficiently explained through doctrine, the intellect can assent by its own light with sufficient evidence and certitude without other experience. And the reason is that the things which are required for such evident assent, whether it be experience or any other declaration of the terms, are not required as the formal reason of assenting, nor as the principle per se effecting or eliciting the act of assenting, but as the sufficient application of the object, as has been declared in the former part of the difficulty. But there is no sufficient reason which persuades that experience rigorously taken, as it includes the intuition, comparison and induction of many singulars, is necessary for the sufficient application of these principles, through sufficient apprehension of the terms, and understanding of their notions, and apt composition. For why can this not be supplied through doctrine, one or another sensible example being used at most, which being sufficiently penetrated by the intellect, the truth of the principle immediately appears self-evident? And experience confirms this very thing; for in admitting these principles in teaching, no one waits for the induction of many singulars, or for experimental knowledge, but each one understands the notions of the terms with the easiest effort, and immediately beholds their truth with the mind, the teacher having applied moderate diligence.

29. For the discovery of the sciences experience of the principles is regularly necessary.—But those who acquire the sciences by discovery alone need experience for the knowledge of these principles, because without it, and without the exterior help of a teacher and of doctrine, these principles cannot be sufficiently proposed, nor the notions of the terms sufficiently known, so that evident assent may be given to them. And the testimonies of Aristotle confirm this, and use itself sufficiently teaches this very thing. The reason, however, is that our intellective knowledge is very limited and imperfect, and depends too much on sense; and therefore without its sufficient aid it cannot proceed with sufficient certitude and firmness; and hence it often happens that those who trust much in the intellect, deserting sense, easily err in natural things, as Aristotle noted, Physics VIII, c. 3. It is necessary, however, to apply a limitation here, namely, that this is to be understood regularly; for someone could be so powerful in talent, and weigh so attentively and considerately the notion, for example, of whole and part in only one singular, that he would immediately draw out from it the truth of the whole principle; just as the theologians say that the soul of Christ, from the mere efficacy of natural talent, without special supernatural aid, drew out many truths or principles from one phantasm. For the medium of experience is not so per se necessary that it cannot be supplied from elsewhere.

30. There are, finally, other principles, particular and proper to the individual sciences, and concerning these it is probable that experience and the comparison of many singulars is necessary for firm and evident assent to them, not only by way of discovery, which is most known, but also by way of instruction, because the notions of the terms in these principles are not so known and easy that any proposition of them whatever suffices, unless the one who learns compares them with the singulars which he knows and sees that they agree rightly with them and with all the things which he has experienced about such matters; likewise that such principles have never suffered an instance (as they say). Finally, in these there is almost always so great a difficulty that one scarcely arrives at the proper assent of principles, or at having them self-evident, but one stops at induction and a posteriori knowledge; it is a sign, therefore, that for obtaining evident assent from the notions of the terms themselves well known, much experience is necessary; greater indeed by way of discovery, but some by way of instruction; although according to the diversity of talents greater or less suffices.

31. Various partitions of science.—In the fifth place Aristotle tacitly proposes the division of art or science (for we have already noted that these names are taken here indifferently) into practical and speculative science, which he distinguishes in this, that the practical are referred to the use and advantage of life, the speculative only to the knowledge of truth. He also tacitly subdivides the practical; for some contribute to the necessities of life, others to pleasure (sensible, of course). Of the former kind are either the mechanical arts, such as shoemaking, etc., or medicine and the like; of the latter kind seem to be the arts which are called liberal, such as music, the art also of painting, and finally all those which pertain to delighting the senses. From all these, then, he separates speculative science, which rests in the contemplation of truth and is only for its sake, so that, although the greatest pleasure follows upon it, nevertheless according to the right and best order of nature it is not sought for the sake of pleasure, but for its own sake; but pleasure only so that it may help toward enjoying the very consideration and contemplation of truth with greater quiet and perseverance. From which he rightly gathers that this kind of science is preferred to the other, and that those are held wiser who intend the contemplation of truth for its own sake. For what is for its own sake is more noble than what is for the sake of another; likewise, because the best thing in man is the contemplation of truth; but this is the more excellent the more it is about higher things and things which are not ordered to operation. Thus far Aristotle.

32. The conclusion from all the sayings of Aristotle now explained.—From which, as I said, he seemed tacitly to conclude that that appetite for knowing which nature has given to man inclines most of all to the contemplation of truth for its own sake, because this is the supreme operation of man. And consequently hence is concluded what was proposed, namely, that this appetite is more inclined to the speculative sciences than to the others, because they are ordered to contemplating truth for its own sake. Whence it is not excluded that we are borne to the practical sciences by the appetite for knowing, but only that we are borne more vehemently to the speculative ones.

33. The practical sciences can be desired for the sake of the knowledge of truth alone.—But you will ask whether the practical sciences too can be desired for the sake of the knowledge of truth, resting in it, without the usefulness of their use. For some seem generally to deny that men can desire the practical sciences only for the sake of knowing, but only for the sake of the work. Nevertheless, although practical science differs from speculative in this, that it is ordered per se to work, while the latter is not, as will be said in its place, this nevertheless does not exclude that practical science proximately and immediately confers the knowledge of some truth; indeed this is necessary, otherwise it would not be science. But every knowledge of truth is lovable per se, even if it brings no other usefulness; for it is per se a great perfection of intellectual nature. Whence the angels know these arts, even though they do not serve them for their use. And therefore the practical sciences too are desirable for the sake of the knowledge of truth, even if one rests in it, and it is not ordered to use. And it is confirmed, because otherwise they would not in truth be desired by virtue of the appetite for knowing, because they would be desired only as means; but a means as a means is not desired except by virtue of the propensity toward the end; and so music would not be desired except by virtue of the appetite for pleasure or gain, and so of the others, but not by virtue of the appetite for science as such, although they are true sciences, perfect in their genus. Which experience also teaches; for many are refreshed in the exercise of these sciences not for the sake of use or usefulness, but only in order to know. Regularly, however, they are sought only for the sake of some human usefulness, both because this is more conformed to the institution and end of such arts, and because sensible advantages or necessities or pleasures move more frequently, and because, if science were to be sought for the sake of truth alone, it would be sought in other more noble sciences, especially since man cannot devote himself to all at once. If, therefore, the practical sciences are indeed desirable, the speculative ones are much more so, if the appetite of man as he is man is regarded, and it is not impeded by other human advantages or necessities.

Resolution of the whole question

34. Finally, from all that has been said the assertion intended is concluded, namely, that metaphysics is most of all desirable by man as he is man, both with natural appetite and with rational appetite best ordered. It is proved tacitly by Aristotle at the end of the same chapter, because among all the speculative sciences this one most of all deserves the name of wisdom, since it is concerned with the first causes and the principles of all things, which has been sufficiently declared by us in the preceding section. If, therefore, the speculative sciences are most of all desired among all, among which this is the supreme, it will certainly be of itself most of all desirable. Finally, the greatest appetite of man is toward his natural happiness; but this is acquired through this science, or rather consists in its perfect attainment. For, as is handed down in Ethics X, this happiness is placed in the contemplation of God and of the separated substances; but this contemplation is the proper act and chief end of this science; therefore natural happiness too consists in an act of this science; this appetite, therefore, is most of all consonant both with nature and with right reason. It remains, therefore, that we investigate this most perfect science with all diligence and study.