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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
Objection 1. It would seem that thesoul does notknow bodies through theintellect. ForAugustine says (Soliloq. ii, 4) that "bodies cannot be understood by theintellect; nor indeed anything corporeal unless it can be perceived by the senses." He says also (Gen. ad lit. xii, 24) thatintellectual vision is of those things that are in thesoul by theiressence. But such are not bodies. Therefore thesoul cannotknow bodies through theintellect.
Objection 2. Further, as sense is to the intelligible, so is theintellect to the sensible. But thesoul can by no means, through the senses, understandspiritual things, which are intelligible. Therefore by no means can it, through theintellect,know bodies, which are sensible.
Objection 3. Further, theintellect is concerned with things that arenecessary and unchangeable. But all bodies are mobile and changeable. Therefore thesoul cannotknow bodies through theintellect.
On the contrary, Science is in theintellect. If, therefore, theintellect does notknow bodies, it follows that there is no science of bodies; and thus perishesnatural science, which treats of mobile bodies.
I answer that, It should be said in order to elucidate this question, that the earlyphilosophers, who inquired into the natures of things, thought there was nothing in the world save bodies. And because they observed that all bodies are mobile, and considered them to be ever in a state of flux, they were of opinion that we can have no certainknowledge of thetruenature of things. For what is in a continual state of flux, cannot be grasped with any degree ofcertitude, for it passes away ere themind can form a judgment thereon: according to the saying of Heraclitus, that "it is not possible twice to touch a drop of water in a passing torrent," as thePhilosopher relates (Metaph. iv, Did. iii, 5).
After these camePlato, who, wishing to save thecertitude of ourknowledge oftruth through theintellect, maintained that, besides these things corporeal, there is another genus of beings, separate frommatter and movement, which beings he called "species" or "ideas," by participation of which each one of these singular and sensible things is said to be either a man, or a horse, or the like. Wherefore he said thatsciences and definitions, and whatever appertains to the act of theintellect, are not referred to these sensible bodies, but to those beings immaterial and separate: so that according to this thesoul does not understand these corporeal things, but the separatespecies thereof.
Now this may be shown to befalse for two reasons.
First, because, since thosespecies are immaterial and immovable,knowledge of movement andmatter would be excluded from science (whichknowledge is proper tonatural science), and likewise all demonstration through moving and materialcauses.
Secondly, because it seems ridiculous, when we seek forknowledge of things which are to us manifest, to introduce other beings, which cannot be thesubstance of those others, since they differ from themessentially: so that granted that we have aknowledge of those separatesubstances, we cannot for that reason claim to form a judgment concerning these sensible things.
Now it seems thatPlato strayed from thetruth because, having observed that allknowledge takes place through some kind of similitude, he thought that the form of the thingknown must ofnecessity be in the knower in the same manner as in the thingknown. Then he observed that the form of the thing understood is in theintellect underconditions of universality, immateriality, and immobility: which is apparent from the very operation of theintellect, whose act of understanding has a universal extension, and is subject to a certain amount ofnecessity: for the mode of action corresponds to the mode of the agent's form. Wherefore he concluded that the things which we understand must have in themselves anexistence under the sameconditions of immateriality and immobility.
But there is nonecessity for this. For even in sensible things it is to be observed that the form is otherwise in one sensible than in another: for instance, whiteness may be of great intensity in one, and of a less intensity in another: in one we find whiteness with sweetness, in another without sweetness. In the same way the sensible form is conditioned differently in the thing which is external to thesoul, and in the senses which receive the forms of sensible things without receivingmatter, such as the color of gold without receiving gold. So also theintellect, according to its own mode, receives underconditions of immateriality and immobility, thespecies of material and mobile bodies: for the received is in the receiver according to the mode of the receiver. We must conclude, therefore, that through theintellect thesoulknows bodies by aknowledge which is immaterial, universal, andnecessary.
Reply to Objection 1. These words ofAugustine are to be understood as referring to the medium ofintellectualknowledge, and not to its object. For theintellectknows bodies by understanding them, not indeed through bodies, nor through material and corporealspecies; but through immaterial and intelligiblespecies, which can be in thesoul by their ownessence.
Reply to Objection 2. AsAugustine says (De Civ. Dei xxii, 29), it is not correct to say that as the senseknows only bodies so theintellectknows onlyspiritual things; for it follows thatGod and theangels would notknow corporeal things. The reason of this diversity is that the lower power does not extend to those things that belong to the higher power; whereas the higher power operates in a more excellent manner those things which belong to the lower power.
Reply to Objection 3. Every movement presupposes something immovable: for when a change ofquality occurs, thesubstance remains unmoved; and when there is a change ofsubstantial form,matter remains unmoved. Moreover the variousconditions of mutable things are themselves immovable; for instance, thoughSocrates be not always sitting, yet it is an immovabletruth that whenever he does sit he remains in one place. For this reason there is nothing to hinder our having an immovable science of movable things.
Objection 1. It would seem that thesoul understands corporeal things through itsessence. ForAugustine says (De Trin. x, 5) that thesoul "collects and lays hold of the images of bodies which are formed in thesoul and of thesoul: for in forming them it gives them something of its ownsubstance." But thesoul understands bodies by images of bodies. Therefore thesoulknows bodies through itsessence, which it employs for the formation of such images, and from which it forms them.
Objection 2. Further, thePhilosopher says (De Anima iii, 8) that "thesoul, after a fashion, is everything." Since, therefore, like isknown by like, it seems that thesoulknows corporeal things through itself.
Objection 3. Further, thesoul is superior to corporeal creatures. Now lower things are in higher things in a more eminent way than in themselves, asDionysius says (Coel. Hier. xii). Therefore all corporeal creaturesexist in a more excellent way in thesoul than in themselves. Therefore thesoul canknow corporeal creatures through itsessence.
On the contrary,Augustine says (De Trin. ix, 3) that "themind gathersknowledge of corporeal things through the bodily senses." But thesoul itself cannot beknown through the bodily senses. Therefore it does notknow corporeal things through itself.
I answer that, The ancientphilosophers held that thesoulknows bodies through itsessence. For it was universally admitted that "like isknown by like." But they thought that the form of the thingknown is in the knower in the same mode as in the thingknown. ThePlatonists however were of a contrary opinion. ForPlato, having observed that theintellectualsoul has an immaterialnature, and an immaterial mode ofknowledge, held that the forms of thingsknown subsist immaterially. While the earliernaturalphilosophers, observing that thingsknown are corporeal and material, held that thingsknown mustexist materially even in thesoul thatknows them. And therefore, in order to ascribe to thesoul aknowledge of all things, they held that it has the samenature in common with all. And because thenature of a result is determined by its principles, they ascribed to thesoul thenature of a principle; so that those who thought fire to be the principle of all, held that thesoul had thenature of fire; and in like manner as to air and water. Lastly, Empedocles, who held theexistence of our four material elements and two principles of movement, said that thesoul was composed of these. Consequently, since they held that thingsexist in thesoul materially, they maintained that all thesoul'sknowledge is material, thus failing to discernintellect from sense.
But this opinion will not hold. First, because in the material principle of which they spoke, the various results do notexist save inpotentiality. But a thing is notknown according as it is inpotentiality, but only according as it is in act, as is shown Metaph. ix (Did. viii, 9): wherefore neither is a powerknown except through its act. It is therefore insufficient to ascribe to thesoul thenature of the principles in order to explain the fact that itknows all, unless we further admit in thesoul natures and forms of eachindividual result, for instance, of bone, flesh, and the like; thus doesAristotle argue against Empedocles (De Anima i, 5). Secondly, because if it werenecessary for the thingknown toexist materially in the knower, there would be no reason why things which have a materialexistence outside thesoul should be devoid ofknowledge; why, for instance, if by fire thesoulknows fire, that fire also which is outside thesoul should not haveknowledge of fire.
We must conclude, therefore, that material thingsknown must needsexist in the knower, not materially, but immaterially. The reason of this is, because the act ofknowledge extends to things outside the knower: for weknow things even that are external to us. Now bymatter the form of a thing is determined to some one thing. Wherefore it is clear thatknowledge is in inverse ratio of materiality. And consequently things that are not receptive of forms save materially, have no power ofknowledge whatever—such as plants, as thePhilosopher says (De Anima ii, 12). But the more immaterially a thing receives the form of the thingknown, the more perfect is itsknowledge. Therefore theintellect which abstracts thespecies not only frommatter, but also from the individuatingconditions ofmatter, has more perfectknowledge than the senses, which receive the form of the thingknown, withoutmatter indeed, but subject to materialconditions. Moreover, among the senses, sight has the most perfectknowledge, because it is the least material, as we have remarked above (I:78:3): while amongintellects the more perfect is the more immaterial.
It is therefore clear from the foregoing, that if there be anintellect whichknows all things by itsessence, then itsessence must needs have all things in itself immaterially; thus the earlyphilosophers held that theessence of thesoul, that it mayknow all things, must be actually composed of the principles of all material things. Now this is proper toGod, that His Essence comprise all things immaterially as effects pre-exist virtually in theircause.God alone, therefore, understands all things through His Essence: but neither thehumansoul nor theangels can do so.
Reply to Objection 1.Augustine in that passage is speaking of animaginary vision, which takes place through the image of bodies. To the formation of such images thesoul gives part of itssubstance, just as a subject is given in order to be informed by some form. In this way thesoul makes such images from itself; not that thesoul or some part of thesoul be turned into this or that image; but just as we say that a body is made into something colored because of its being informed with color. That this is the sense, is clear from what follows. For he says that thesoul "keeps something"—namely, not informed with such image—"which is able freely to judge of thespecies of these images": and that this is the "mind" or "intellect." And he says that the part which is informed with these images—namely, theimagination—is "common to us and beasts."
Reply to Objection 2.Aristotle did not hold that thesoul is actually composed of all things, as did the earlierphilosophers; he said that thesoul is all things, "after a fashion," forasmuch as it is inpotentiality to all—through the senses, to all things sensible—through theintellect, to all things intelligible.
Reply to Objection 3. Every creature has a finite and determinateessence. Wherefore although theessence of the higher creature has a certain likeness to the lower creature, forasmuch as they have something in common generically, yet it has not a complete likeness thereof, because it is determined to a certainspecies other than thespecies of the lower creature. But the Divine Essence is a perfect likeness of all, whatsoever may be found toexist in thingscreated, being the universal principle of all.
Objection 1. It would seem that thesoul understands all things through innatespecies. ForGregory says, in ahomily for the Ascension (xxix in Ev.), that "man has understanding in common with theangels." Butangels understand all things through innatespecies: wherefore in the book De Causis it is said that "everyintelligence is full of forms." Therefore thesoul also has innatespecies of things, by means of which it understands corporeal things.
Objection 2. Further, theintellectualsoul is more excellent than corporeal primarymatter. But primarymatter wascreated byGod under the forms to which it haspotentiality. Therefore much more is theintellectualsoulcreated byGod under intelligiblespecies. And so thesoul understands corporeal things through innatespecies.
Objection 3. Further, no one can answer thetruth except concerning what heknows. But even aperson untaught and devoid of acquiredknowledge, answers thetruth to every question if put to him in orderly fashion, as we find related in the Meno (xv seqq.) ofPlato, concerning a certainindividual. Therefore we have someknowledge of things even before we acquireknowledge; which would not be the case unless we had innatespecies. Therefore thesoul understands corporeal things through innatespecies.
On the contrary, ThePhilosopher, speaking of theintellect, says (De Anima iii, 4) that it is like "a tablet on which nothing is written."
I answer that, Since form is the principle of action, a thing must be related to the form which is the principle of an action, as it is to that action: for instance, if upward motion is from lightness, then that which onlypotentially moves upwards must needs be onlypotentially light, but that which actually moves upwards must needs be actually light. Now we observe thatman sometimes is only apotential knower, both as to sense and as tointellect. And he is reduced from suchpotentiality to act—through the action of sensible objects on his senses, to the act of sensation—by instruction or discovery, to the act of understanding. Wherefore we must say that the cognitivesoul is inpotentiality both to the images which are the principles of sensing, and to those which are the principles of understanding. For this reasonAristotle (De Anima iii, 4) held that theintellect by which thesoul understands has no innatespecies, but is at first inpotentiality to all suchspecies.
But since that which has a form actually, is sometimes unable to act according to that form on account of some hindrance, as a light thing may be hindered from moving upwards; for this reason didPlato hold thatnaturallyman'sintellect is filled with all intelligiblespecies, but that, by being united to the body, it is hindered from the realization of its act. But this seems to be unreasonable.
First, because, if thesoul has anaturalknowledge of all things, it seems impossible for thesoul so far to forget theexistence of suchknowledge as not toknow itself to be possessed thereof: for noman forgets what heknowsnaturally; that, for instance, the whole is larger than the part, and such like. And especially unreasonable does this seem if we suppose that it isnatural to thesoul to be united to the body, as we have established above (I:76:1: for it is unreasonable that thenatural operation of a thing be totally hindered by that which belongs to itnaturally.
Secondly, the falseness of this opinion is clearlyproved from the fact that if a sense be wanting, theknowledge of what is apprehended through that sense is wanting also: for instance, a man who is born blind can have noknowledge of colors. This would not be the case if thesoul had innate images of all intelligible things. We must therefore conclude that thesoul does notknow corporeal things through innatespecies.
Reply to Objection 1. Man indeed hasintelligence in common with theangels, but not in the same degree of perfection: just as the lower grades of bodies, which merelyexist, according toGregory (Homily on Ascension, xxix In Ev.), have not the same degree of perfection as the higher bodies. For thematter of the lower bodies is not totally completed by itsform, but is inpotentiality to forms which it has not: whereas thematter of heavenly bodies is totally completed by itsform, so that it is not inpotentiality to any other form, as we have said above (I:66:2). In the same way theangelicintellect is perfected by intelligiblespecies, in accordance with itsnature; whereas thehumanintellect is inpotentiality to suchspecies.
Reply to Objection 2. Primarymatter hassubstantial being through itsform, consequently it had need to becreated under some form: else it would not be in act. But when once itexists under one form it is inpotentiality to others. On the other hand, theintellect does not receivesubstantial being through the intelligiblespecies; and therefore there is no comparison.
Reply to Objection 3. If questions be put in an orderly fashion they proceed from universal self-evident principles to what is particular. Now by such a processknowledge is produced in themind of the learner. Wherefore when he answers thetruth to a subsequent question, this is not because he hadknowledge previously, but because he thus learns for the first time. For it matters not whether the teacher proceed from universal principles to conclusions by questioning or by asserting; for in either case themind of the listener is assured of what follows by that which preceded.
Objection 1. It would seem that the intelligiblespecies are derived by thesoul from some separate forms. For whatever is such by participation iscaused by what is suchessentially; for instance, that which is on fire is reduced to fire as thecause thereof. But theintellectualsoul forasmuch as it is actually understanding, participates the thing understood: for, in a way, theintellect in act is the thing understood in act. Therefore what in itself and in itsessence is understood in act, is thecause that theintellectualsoul actually understands. Now that which in itsessence is actually understood is a formexisting withoutmatter. Therefore the intelligiblespecies, by which thesoul understands, arecaused by some separate forms.
Objection 2. Further, the intelligible is to theintellect, as the sensible is to the sense. But the sensiblespecies which are in the senses, and by which we sense, arecaused by the sensible object whichexists actually outside thesoul. Therefore the intelligiblespecies, by which ourintellect understands, arecaused by some things actually intelligible,existing outside thesoul. But these can be nothing else than forms separate frommatter. Therefore the intelligible forms of ourintellect are derived from some separatesubstances.
Objection 3. Further, whatever is inpotentiality is reduced to act by something actual. If, therefore, ourintellect, previously inpotentiality, afterwards actually understands, this must needs becaused by someintellect which is always in act. But this is a separateintellect. Therefore the intelligiblespecies, by which we actually understand, arecaused by some separatesubstances.
On the contrary, If this weretrue we should not need the senses in order to understand. And this isproved to befalse especially from the fact that if a man be wanting in a sense, he cannot have anyknowledge of the sensibles corresponding to that sense.
I answer that, Some have held that the intelligiblespecies of ourintellect are derived from certain separate forms orsubstances. And this in two ways. ForPlato, as we have said (Article 1), held that the forms of sensible things subsist by themselves withoutmatter; for instance, the form of a man which he calledper seman, and the form oridea of a horse which is calledper se horse, and so forth. He said therefore that these forms are participated both by oursoul and by corporealmatter; by oursoul, to the effect ofknowledge thereof, and by corporealmatter to the effect ofexistence: so that, just as corporealmatter by participating theidea of a stone, becomes an individuating stone, so ourintellect, by participating theidea of a stone, is made to understand a stone. Now participation of anidea takes place by some image of theidea in the participator, just as a model is participated by a copy. So just as he held that the sensible forms, which are in corporealmatter, are derived from theideas as certain images thereof: so he held that the intelligiblespecies of ourintellect are images of theideas, derived therefrom. And for this reason, as we have said above (Article 1), he referredsciences and definitions to thoseideas.
But since it is contrary to thenature of sensible things that their forms should subsist withoutmatter, asAristotle proves in many ways (Metaph. vi),Avicenna (De Anima v) setting this opinion aside, held that the intelligiblespecies of all sensible things, instead of subsisting in themselves withoutmatter, pre-exist immaterially in the separateintellects: from the first of which, said he, suchspecies are derived by a second, and so on to the last separateintellect which he called the "activeintelligence," from which, according to him, intelligiblespecies flow into oursouls, and sensiblespecies into corporealmatter. And soAvicenna agrees withPlato in this, that the intelligiblespecies of ourintellect are derived from certain separate forms; but thesePlato held to subsist of themselves, whileAvicenna placed them in the "activeintelligence." They differ, too, in this respect, thatAvicenna held that the intelligiblespecies do not remain in ourintellect after it has ceased actually to understand, and that it needs to turn (to the activeintellect) in order to receive them anew. Consequently he does not hold that thesoul has innateknowledge, asPlato, who held that the participatedideas remain immovably in thesoul.
But in this opinion no sufficient reason can be assigned for thesoul being united to the body. For it cannot be said that theintellectualsoul is united to the body for the sake of the body: for neither is form for the sake ofmatter, nor is the mover for the sake of the moved, but rather the reverse. Especially does the body seemnecessary to theintellectualsoul, for the latter's proper operation which is to understand: since as to its being thesoul does not depend on the body. But if thesoul by its verynature had an inborn aptitude for receiving intelligiblespecies through the influence of only certain separate principles, and were not to receive them from the senses, it would not need the body in order to understand: wherefore to no purpose would it be united to the body.
But if it be said that oursoul needs the senses in order to understand, through being in some way awakened by them to the consideration of those things, the intelligiblespecies of which it receives from the separate principles: even this seems an insufficient explanation. For this awakening does not seemnecessary to thesoul, except in as far as it is overcome by sluggishness, as thePlatonists expressed it, and by forgetfulness, through its union with the body: and thus the senses would be of no use to theintellectualsoul except for the purpose of removing the obstacle which thesoul encounters through its union with the body. Consequently the reason of the union of thesoul with the body still remains to be sought.
And if it be said withAvicenna, that the senses arenecessary to thesoul, because by them it is aroused to turn to the "activeintelligence" from which it receives thespecies: neither is this a sufficient explanation. Because if it isnatural for thesoul to understand throughspecies derived from the "activeintelligence," it follows that at times thesoul of anindividual wanting in one of the senses can turn to the activeintelligence, either from the inclination of its verynature, or through being roused by another sense, to the effect of receiving the intelligiblespecies of which the corresponding sensiblespecies are wanting. And thus a man born blind could haveknowledge of colors; which is clearlyuntrue. We must therefore conclude that the intelligiblespecies, by which oursoul understands, are not derived from separate forms.
Reply to Objection 1. The intelligiblespecies which are participated by ourintellect are reduced, as to their firstcause, to a first principle which is by itsessence intelligible—namely,God. But they proceed from that principle by means of the sensible forms and material things, from which we gatherknowledge, asDionysius says (Div. Nom. vii).
Reply to Objection 2. Material things, as to the being which they have outside thesoul, may be actually sensible, but not actually intelligible. Wherefore there is no comparison between sense andintellect.
Reply to Objection 3. Our passiveintellect is reduced frompotentiality to act by some being in act, that is, by the activeintellect, which is a power of thesoul, as we have said (I:79:4; and not by a separateintelligence, as proximatecause, although perchance as remotecause.
Objection 1. It would seem that theintellectualsoul does notknow material things in theeternal types. For that in which anything isknown must itself beknown more and previously. But theintellectualsoul ofman, in the present state of life, does notknow theeternal types: for it does notknowGod in Whom theeternal typesexist, but is "united toGod as to the unknown," asDionysius says (Myst. Theolog. i). Therefore thesoul does notknow all in theeternal types.
Objection 2. Further, it is written (Romans 1:20) that "the invisible things ofGod are clearly seen . . . by the things that are made." But among the invisible things ofGod are theeternal types. Therefore theeternal types areknown through creatures and not the converse.
Objection 3. Further, theeternal types are nothing else butideas, forAugustine says (QQ. 83, qu. 46) that "ideas are permanent typesexisting in the Divine mind." If therefore we say that theintellectualsoulknows all things in theeternal types, we come back to the opinion ofPlato who said that allknowledge is derived from them.
On the contrary,Augustine says (Confess. xii, 25): "If we both see that what you say istrue, and if we both see that what I say istrue, where do we see this, Ipray? Neither do I see it in you, nor do you see it in me: but we both see it in the unchangeabletruth which is above ourminds." Now the unchangeabletruth is contained in theeternal types. Therefore theintellectualsoulknows alltrue things in theeternal types.
I answer that, AsAugustine says (De Doctr. Christ. ii, 11): "If those who are calledphilosophers said by chance anything that wastrue and consistent with ourfaith, we must claim it from them as fromunjust possessors. For some of the doctrines of theheathens are spurious imitations orsuperstitious inventions, which we must be careful to avoid when we renounce the society of theheathens." Consequently wheneverAugustine, who was imbued with the doctrines of thePlatonists, found in their teaching anything consistent withfaith, he adopted it: and those thing which he found contrary tofaith he amended. NowPlato held, as we have said above (Article 4), that the forms of things subsist of themselves apart frommatter; and these he calledideas, by participation of which he said that ourintellectknows all things: so that just as corporealmatter by participating theidea of a stone becomes a stone, so ourintellect, by participating the sameidea, hasknowledge of a stone. But since it seems contrary tofaith that forms of things should subsist of themselves, outside the things themselves and apart frommatter, as thePlatonists held, asserting thatper se life orper se wisdom are creativesubstances, asDionysius relates (Div. Nom. xi); thereforeAugustine (QQ. 83, qu. 46), for theideas defended byPlato, substituted the types of all creaturesexisting in the Divine mind, according to which types all things are made in themselves, and areknown to thehumansoul.
When, therefore, the question is asked: Does thehumansoulknow all things in theeternal types? we must reply that one thing is said to beknown in another in two ways.
First, as in an object itselfknown; as one may see in a mirror the images of things reflected therein. In this way thesoul, in the present state of life, cannot see all things in theeternal types; but the blessed who seeGod, and all things in Him, thusknow all things in theeternal types.
Secondly, one thing is said to beknown in another as in a principle ofknowledge: thus we might say that we see in the sun what we see by the sun. And thus we must needs say that thehumansoulknows all things in theeternal types, since by participation of these types weknow all things. For theintellectual light itself which is in us, is nothing else than a participated likeness of the uncreated light, in which are contained theeternal types. Whence it is written (Psalm 4:6-7), "Many say: Who showeth usgood things?" which question the Psalmist answers, "The light of Thy countenance, O Lord, is signed upon us," as though he were to say: By the seal of the Divine light in us, all things are madeknown to us.
But since besides theintellectual light which is in us, intelligiblespecies, which are derived from things, are required in order for us to haveknowledge of material things; therefore this sameknowledge is not due merely to a participation of theeternal types, as thePlatonists held, maintaining that the mere participation ofideas sufficed forknowledge. WhereforeAugustine says (De Trin. iv, 16): "Although thephilosophersprove by convincing arguments that all things occur intime according to theeternal types, were they able to see in theeternal types, or to find out from them how many kinds of animals there are and the origin of each? Did they not seek for this information from the story of times and places?"
But thatAugustine did not understand all things to beknown in their "eternal types" or in the "unchangeabletruth," as though theeternal types themselves were seen, is clear from what he says (QQ. 83, qu. 46)—viz. that "not each and every rationalsoul can be said to be worthy of that vision," namely, of theeternal types, "but only those that areholy and pure," such as thesouls of the blessed.
From what has been said the objections are easily solved.
Objection 1. It would seem thatintellectualknowledge is not derived from sensible things. ForAugustine says (QQ. 83, qu. 9) that "we cannot expect to learn the fulness oftruth from the senses of the body." This he proves in two ways.
First, because "whatever the bodily senses reach, is continually being changed; and what is never the same cannot be perceived."
Secondly, because, "whatever we perceive by the body, even when not present to the senses, may be present to theimagination, as when we are asleep orangry: yet we cannot discern by the senses, whether what we perceive be the sensible object or the deceptive image thereof. Now nothing can be perceived which cannot be distinguished from its counterfeit." And so he concludes that we cannot expect to learn thetruth from the senses. Butintellectualknowledge apprehends thetruth. Thereforeintellectualknowledge cannot be conveyed by the senses.
Objection 2. Further,Augustine says (Gen. ad lit. xii, 16): "We must not think that the body can make any impression on the spirit, as though the spirit were to supply the place ofmatter in regard to the body's action; for that which acts is in every way more excellent than that which it acts on." Whence he concludes that "the body does notcause its image in the spirit, but the spiritcauses it in itself." Thereforeintellectualknowledge is not derived from sensible things.
Objection 3. Further, an effect does not surpass the power of itscause. Butintellectualknowledge extends beyond sensible things: for we understand some things which cannot be perceived by the senses. Thereforeintellectualknowledge is not derived from sensible things.
On the contrary, ThePhilosopher says (Metaph. i, 1; Poster. ii, 15) that the principle ofknowledge is in the senses.
I answer that, On this point thephilosophers held three opinions. For Democritus held that "allknowledge iscaused by images issuing from the bodies we think of and entering into oursouls," asAugustine says in his letter to Dioscorus (cxviii, 4). AndAristotle says (De Somn. et Vigil.) that Democritus held thatknowledge iscause by a "discharge of images." And the reason for this opinion was that both Democritus and the other earlyphilosophers did not distinguish betweenintellect and sense, asAristotle relates (De Anima iii, 3). Consequently, since the sense is affected by the sensible, they thought that all ourknowledge is affected by this mere impression brought about by sensible things. Which impression Democritus held to becaused by a discharge of images.
Plato, on the other hand, held that theintellect is distinct from the senses: and that it is an immaterial power not making use of a corporeal organ for its action. And since the incorporeal cannot be affected by the corporeal, he held thatintellectualknowledge is not brought about by sensible things affecting theintellect, but by separate intelligible forms being participated by theintellect, as we have said above (Articles4 and5). Moreover he held that sense is a power operating of itself. Consequently neither is sense, since it is aspiritual power, affected by the sensible: but the sensible organs are affected by the sensible, the result being that thesoul is in a way roused to form within itself thespecies of the sensible.Augustine seems to touch on this opinion (Gen. ad lit. xii, 24) where he says that the "body feels not, but thesoul through the body, which it makes use of as a kind of messenger, for reproducing within itself what is announced from without." Thus according toPlato, neither doesintellectualknowledge proceed from sensibleknowledge, nor sensibleknowledge exclusively from sensible things; but these rouse the sensiblesoul to the sentient act, while the senses rouse theintellect to the act of understanding.
Aristotle chose a middle course. For withPlato he agreed thatintellect and sense are different. But he held that the sense has not its proper operation without the cooperation of the body; so that to feel is not an act of thesoul alone, but of the "composite." And he held the same in regard to all the operations of the sensitive part. Since, therefore, it is not unreasonable that the sensible objects which are outside thesoul should produce some effect in the "composite,"Aristotle agreed with Democritus in this, that the operations of the sensitive part arecaused by the impression of the sensible on the sense: not by a discharge, as Democritus said, but by some kind of operation. For Democritus maintained that every operation is by way of a discharge of atoms, as we gather from De Gener. i, 8. ButAristotle held that theintellect has an operation which is independent of the body's cooperation. Now nothing corporeal can make an impression on the incorporeal. And therefore in order tocause theintellectual operation according toAristotle, the impressioncaused by the sensible does not suffice, but something more noble is required, for "the agent is more noble than the patient," as he says (De Gener. i, 5). Not, indeed, in the sense that theintellectual operation is effected in us by the mere impression of some superior beings, asPlato held; but that the higher and more noble agent which he calls the activeintellect, of which we have spoken above (I:79:4)causes the phantasms received from the senses to be actually intelligible, by a process ofabstraction.
According to this opinion, then, on the part of the phantasms,intellectualknowledge iscaused by the senses. But since the phantasms cannot of themselves affect the passiveintellect, and require to be made actually intelligible by the activeintellect, it cannot be said that sensibleknowledge is the total and perfectcause ofintellectualknowledge, but rather that it is in a way the materialcause.
Reply to Objection 1. Those words ofAugustine mean that we must not expect the entiretruth from the senses. For the light of the activeintellect is needed, through which we achieve the unchangeabletruth of changeable things, and discern things themselves from their likeness.
Reply to Objection 2. In this passageAugustine speaks not ofintellectual but ofimaginaryknowledge. And since, according to the opinion ofPlato, theimagination has an operation which belongs to thesoul only,Augustine, in order to show that corporeal images are impressed on theimagination, not by bodies but by thesoul, uses the same argument asAristotle does inproving that the activeintellect must be separate, namely, because "the agent is more noble than the patient." And withoutdoubt, according to the above opinion, in theimagination there must needs be not only a passive but also an active power. But if we hold, according to the opinion ofAristotle, that the action of theimagination, is an action of the "composite," there is no difficulty; because the sensible body is more noble than the organ of the animal, in so far as it is compared to it as a being in act to a being inpotentiality; even as the object actually colored is compared to the pupil which ispotentially colored. It may, however, be said, although the first impression of theimagination is through the agency of the sensible, since "fancy is movement produced in accordance with sensation" (De Anima iii, 3), that nevertheless there is inman an operation which by synthesis and analysis forms images of various things, even of things not perceived by the senses. AndAugustine's words may be taken in this sense.
Reply to Objection 3. Sensitiveknowledge is not the entirecause ofintellectualknowledge. And therefore it is not strange thatintellectualknowledge should extend further than sensitiveknowledge.
Objection 1. It would seem that theintellect can actually understand through the intelligiblespecies of which it is possessed, without turning to the phantasms. For theintellect is made actual by the intelligiblespecies by which it is informed. But if theintellect is in act, it understands. Therefore the intelligiblespecies suffices for theintellect to understand actually, without turning to the phantasms.
Objection 2. Further, theimagination is more dependent on the senses than theintellect on theimagination. But theimagination can actuallyimagine in the absence of the sensible. Therefore much more can theintellect understand without turning to the phantasms.
Objection 3. There are no phantasms of incorporeal things: for theimagination does not transcend time and space. If, therefore, ourintellect cannot understand anything actually without turning to the phantasms, it follows that it cannot understand anything incorporeal. Which is clearlyfalse: for we understandtruth, andGod, and theangels.
On the contrary, ThePhilosopher says (De Anima iii, 7) that "thesoul understands nothing without a phantasm."
I answer that, In the present state of life in which thesoul is united to a passible body, it is impossible for ourintellect to understand anything actually, except by turning to the phantasms.
First of all because theintellect, being a power that does not make use of a corporeal organ, would in no way be hindered in its act through the lesion of a corporeal organ, if for its act there were not required the act of some power that does make use of a corporeal organ. Now sense,imagination and the other powers belonging to the sensitive part, make use of a corporeal organ. Wherefore it is clear that for theintellect to understand actually, not only when it acquires freshknowledge, but also when it appliesknowledge already acquired, there is need for the act of theimagination and of the other powers. For when the act of theimagination is hindered by a lesion of the corporeal organ, for instance in a case of frenzy; or when the act of thememory is hindered, as in the case of lethargy, we see that a man is hindered from actually understanding things of which he had a previousknowledge.
Secondly, anyone can experience this of himself, that when he tries to understand something, he forms certain phantasms to serve him by way of examples, in which as it were he examines what he is desirous of understanding. For this reason it is that when we wish to help someone to understand something, we lay examples before him, from which he forms phantasms for the purpose of understanding.
Now the reason of this is that the power ofknowledge is proportioned to the thingknown. Wherefore the proper object of theangelicintellect, which is entirely separate from a body, is an intelligiblesubstance separate from a body. Whereas the proper object of thehumanintellect, which is united to a body, is a quiddity ornatureexisting in corporealmatter; and through such natures of visible things it rises to a certainknowledge of things invisible. Now it belongs to such anature toexist in anindividual, and this cannot be apart from corporealmatter: for instance, it belongs to thenature of a stone to be in anindividual stone, and to thenature of a horse to be in anindividual horse, and so forth. Wherefore thenature of a stone or any material thing cannot beknown completely andtruly, except in as much as it isknown asexisting in theindividual. Now we apprehend theindividual through the senses and theimagination. And, therefore, for theintellect to understand actually its proper object, it must ofnecessity turn to the phantasms in order to perceive the universalnatureexisting in theindividual. But if the proper object of ourintellect were a separate form; or if, as thePlatonists say, the natures of sensible things subsisted apart from theindividual; there would be no need for theintellect to turn to the phantasms whenever it understands.
Reply to Objection 1. Thespecies preserved in the passiveintellectexist therehabitually when it does not understand them actually, as we have said above (I:79:6). Wherefore for us to understand actually, the fact that thespecies are preserved does not suffice; we need further to make use of them in a manner befitting the things of which they are thespecies, which things are naturesexisting inindividuals.
Reply to Objection 2. Even the phantasm is the likeness of anindividual thing; wherefore theimagination does not need any further likeness of theindividual, whereas theintellect does.
Reply to Objection 3. Incorporeal things, of which there are no phantasms, areknown to us by comparison with sensible bodies of which there are phantasms. Thus we understandtruth by considering a thing of which we possess thetruth; andGod, asDionysius says (Div. Nom. i), weknow ascause, by way of excess and by way of remotion. Otherincorporeal substances weknow, in the present state of life, only by way of remotion or by some comparison to corporeal things. And, therefore, when we understand something about these things, we need to turn to phantasms of bodies, although there are no phantasms of the things themselves.
Objection 1. It would seem that the judgment of theintellect is not hindered by suspension of the sensitive powers. For the superior does not depend on the inferior. But the judgment of theintellect is higher than the senses. Therefore the judgment of theintellect is not hindered through suspension of the senses.
Objection 2. Further, to syllogize is an act of theintellect. But during sleep the senses are suspended, as is said in De Somn. et Vigil. i and yet it sometimes happens to us to syllogize while asleep. Therefore the judgment of theintellect is not hindered through suspension of the senses.
On the contrary, What a man does while asleep, against the morallaw, is not imputed to him as asin; asAugustine says (Gen. ad lit. xii, 15). But this would not be the case ifman, while asleep, had free use of hisreason andintellect. Therefore the judgment of theintellect is hindered by suspension of the senses.
I answer that, As we have said above (Article 7), ourintellect's proper and proportionate object is thenature of a sensible thing. Now a perfect judgment concerning anything cannot be formed, unless all that pertains to that thing'snature beknown; especially if that be ignored which is the term and end of judgment. Now thePhilosopher says (De Coel. iii), that "as the end of a practical science is action, so the end ofnatural science is that which is perceived principally through the senses"; for the smith does not seekknowledge of a knife except for the purpose of action, in order that he may produce a certainindividual knife; and in like manner thenatural philosopher does not seek toknow thenature of a stone and of a horse, save for the purpose ofknowing theessential properties of those things which he perceives with his senses. Now it is clear that a smith cannot judge perfectly of a knife unless heknows the action of the knife: and in like manner thenatural philosopher cannot judge perfectly ofnatural things, unless heknows sensible things. But in the present state of life whatever we understand, weknow by comparison tonatural sensible things. Consequently it is not possible for ourintellect to form a perfect judgment, while the senses are suspended, through which sensible things areknown to us.
Reply to Objection 1. Although theintellect is superior to the senses, nevertheless in a manner it receives from the senses, and its first and principal objects are founded in sensible things. And therefore suspension of the sensesnecessarily involves a hindrance to the judgment of theintellect.
Reply to Objection 2. The senses are suspended in the sleeper through certain evaporations and the escape of certain exhalations, as we read in De Somn. et Vigil. iii. And, therefore, according to the amount of such evaporation, the senses are more or less suspended. For when the amount is considerable, not only are the senses suspended, but also theimagination, so that there are no phantasms; thus does it happen, especially when a man falls asleep after eating and drinking copiously. If, however, the evaporation be somewhat less, phantasms appear, but distorted and without sequence; thus it happens in a case of fever. And if the evaporation be still more attenuated, the phantasms will have a certain sequence: thus especially does it happen towards the end of sleep in sober men and those who are gifted with a strongimagination. If the evaporation be very slight, not only does theimagination retain its freedom, but also thecommon sense is partly freed; so that sometimes while asleep a man may judge that what he sees is a dream, discerning, as it were, between things, and their images. Nevertheless, thecommon sense remains partly suspended; and therefore, although it discriminates some images from the reality, yet is it always deceived in some particular. Therefore, whileman is asleep, according as sense andimagination are free, so is the judgment of hisintellect unfettered, though not entirely. Consequently, if a man syllogizes while asleep, when he wakes up he invariably recognizes a flaw in some respect.