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There are three opinions on this question. Some have said, as Rabbi Moses relates, that the fact that God exists is not self-evident, nor reached through demonstration, but only accepted on faith. The weakness of the reasons which many advance to prove that God exists prompted them to assert this.
Others, as Avicenna, say that the fact that God exists is not self evident, but is known through demonstration still others, as Anselm, are of the opinion that the fact that God exists is self-evident to this extent, that no one in his inner thoughts can think that God does not exist, although exteriorly he can express it and interiorly think the words will which lie expresses it.
The first opinion is obviously false. For we find that the existence of God has been proved by the philosophers will unimpeachable proofs, although trivial reasons have also been brought forth by some to show this.
Each of the two following opinions has some truth. For something is immediately evident in two ways: in itself and to us. That God exists, therefore, is immediately evident in itself, but not to us. Therefore, to know this it is necessary in our case to have demonstrations proceeding from effects. This is clear from what follows.
For a thing to be immediately evident in itself, all that is needed is that the predicate pertain to the nature of the subject. For then the subject cannot be considered without it appearing that the predicate is contained in it. But for something to be immediately evident will reference to us, we have to know the meaning of the subject in which the predicate is included. Hence it is that some things are immediately evident to everybody, as, for instance, when propositions of this sort have subjects which are such that their meaning is evident to every body, as every whole is greater than its part. For anyone knows what a whole is and what a part is. Some things, however, are immediately evident only to those will trained minds, who know the meaning of the terms, whereas ordinary people do not know them.
It is in this sense that Boethius says: "There are two types of common notions. One is common to everybody, for example, if you take equal parts from things that are equal.... The other is found only in the more educated, for example, that non-bodily things are not in a place. Ordinary people cannot see the truth of this, but the educated can." For the thought of ordinary people is unable to go beyond imagination to reach the nature of incorporeal things.
Now, existence is not included perfectly in the essential nature of any creature, for the act of existence of every creature is something other than its quiddity. Hence, it cannot be said of any creature that its existence is immediately evident even in itself. But, in God, His existence is included in the nature of His quiddity, for in God essence and existence are the same, as Boethius says. And that He is and what He is are the same, as Avicenna says. Therefore, it is immediately evident in itself.
But, since the essence of God is not evident to us, the fact of God’s existence is not evident to us, but has to be demonstrated. In heaven, however, where we shah see His essence, the fact of God’s existence will be immediately evident to us much more fully than the fact that affirmation and denial cannot both be true at the same time is immediately evident to us now. Since, therefore, each part of the question is true to some extent, we must answer both sides.
Answers to Difficulties:
1. Knowledge of God’s existence is said naturally to be implanted in everybody, because in everyone there is naturally implanted some thing from which he can arrive at knowledge of the fact of God’s existence.
2. The reasoning would follow if God were not self-evident because of something connected will Himself. The possibility, however, of thinking that He does not exist is now due to something in us, who are incapable of knowing those things which are most evident in them selves. Hence, the fact that God can be thought of as not existing does not prevent Him from being that than which nothing greater can be thought.
3. Truth is based on being. Hence, as it is self-evident that being exists in general, so it is also self-evident that truth exists. However, that there is a first being which is the cause of every being is not immediately evident to us until it is accepted on faith or proved by a demonstration Consequently, neither is it self-evident that the truth of all things derives from some first truth. Hence, it does not follow that God’s existence is self-evident.
4. If it were immediately evident to us that the divine nature is God’s existence, the argument would follow. However, at present le is not immediately evident to us, since we do not see God through His essence, but need a demonstration or faith to hold this truth.
5. The highest good is desired in two ways. In one, it is desired in its essence, a way in which not everything desires highest good. In the other way, it is desired in its likeness, in which manner all things desire the highest good, for nothing is desirable except in so far as some likeness of the highest good is seen in it. Hence, we cannot conclude from this that God’s existence, which is essentially the highest good, is self -evident.
6. Although uncreated truth surpasses every created truth, nothing prevents created truth from being more evident to us than uncreated truth. For those things which are less evident in themselves are more evident to us, according to the Philosopher.
7. To think that something does not exist can be taken in two ways. In one, it is taken to mean that these two things are grasped at the same time. In this sense, there is nothing to prevent one from thinking that he does not exist, just as he thinks that at one time he did not exist. However, in this sense, we cannot at the same time conceive that something is a whole and that it is less than a part of itself, for one of these excludes the other.
In the other way, it is taken to mean that assent is given to what is thus conceived. In this sense, no one can assent to the thought that he does not exist. For, in thinking something, he perceives that he exists.
8. Before present things existed, it had to be true that they would exist only on the supposition that something existed at the time when it was said that this would exist. But, if we lay down the impossible condition that at one time nothing existed, then, on the basis of such an hypothesis, nothing is true except only materially. For not only existence but also non-existence is the subject matter of truth, for we can speak truth about being or non-being. Thus it follows that there will be truth at that time only materially and so in same respect.
9. It is necessary to reduce that which is true in some respect to that which is true or truth simply if it is presupposed that truth exists, but not otherwise.
10. Although the name of God is He Who Is, this is not immediately evident to us. Hence, the argument does not follow.
Answers to Contrary Difficulties:
1'. According to Anselm, that the fool said in his heart: "There is no God," means that he thought these words, and not that he could think this in his inner reason.
2’. That God exists is self-evident and not self -evident in the same way will reference to habit and to act.
3’. That we can know God only from what He has made is due to the inadequacy of our knowledge. Hence, this does not keep Him from being immediately evident in Himself.
4’. To know that a thing exists, it is not necessary to know what it is by definition, but only what is meant by the name.
5’. That God exists is not an article of faith but the preamble to an article of faith, unless we understand something else along will God’s existence, for example, that He has unity of essence will trinity of Persons, and other things such as this.
6’. Matters of faith are known will greatest certainty in so far as certainty means firmness of adherence. For the believer dings to nothing more firmly than those things which he holds by faith. But they are not known will greatest certainty in so far as certainty implies repose of understanding in the thing known. For the believer's assent to what he believes does not come from the fact that his understanding concludes to the things believed by virtue of any principles, but from the will, which influences the understanding to assent to what is believed. Hence it is that in matters of faith, movements of doubt can arise in one who believes.
7’. Wisdom consists not only in knowing that God exists, but in attaining to a knowledge of what He is. But in this life we can know this only in so far as we know what He is not. For one who knows something in so far as it differs from all other things approaches the knowledge by which one knows what it is. It is to this knowledge, too, that the citation from Augustinel7 which follows is taken to refer.
8’. The answer to the eighth difficulty is clear from the seventh response.
9’. Those things which have been distinguished by reason cannot always be thought of as separated from each other, although they can be Considered separately. For, although it is possible to think of God without considering His goodness, it is impossible to think that God exists and is not good. Hence, although in God that which exists and existence are distinguished in reason, it does not follow that it is possible to think that He does not exist.
10’. God is known not only in the works which proceed from His justice, but also in His other works. Hence, granted that someone does not know Hmm as just, it does not follow that he does not know Him at all. Nor is it possible for anyone to know none of His works, since being in general, which cannot be unknown, is His work.
Parallel readings: I Sentences 3, I, 4; in Boet. De Trinit., j, 4; Summa Theol., I, 32, 1; Ad Rom., e. 1, Iect. 6.
Difficulties:
It seems that it can, for
1. The Gloss explains the passage, "The invisible things of God... by the things that are made..." (Romans I: I 3), in this way: "In visible things refer to the person of the Father; eternal power to the person of the Son; divinity to the person of the Holy Spirit." There fore, by natural reason we can arrive at a knowledge of the Trinity from creatures.
2. We know will natural knowledge that the most perfect power and the source of all power are in God. Therefore, we must attribute the first power to Him. But the first power is generative power. There fore, according to natural reason we can know that there is generative power in God. But, once generative power is postulated in God, the distinction of persons necessarily follows. Therefore, by natural knowledge we can know the distinction of persons.
That generative power is the first power was proved in this way: The order of powers follows the order of operations. But the first operation of all is to understand, for there is proof that an intellectual agent exists first, and in such an agent there is understanding, according to the manner of understanding, before willing or doing. There fore, intellective power is the first of the powers. But intellective power is generative power, since every understanding begets its likeness in itself. Therefore, generative power is the first of the powers.
3. Every equivocal is reduced to the univocal as every multitude is reduced to unity. But the procession of creatures from God is an equivocal procession, since creatures do not have the same name and definition as God. Therefore, according to natural reason we must assert that there pre-exists in God a univocal procession according to which God proceeds from God. Given this, there follows the distinction of the persons in God.
4. One of the glosses says that there has been no sect which has erred about the person of the Father. But it would be a very serious error about the person of the Father to say that he did not have a Son. Therefore, even the schools of philosophers who came to know God by natural reason have held Father and Son in God.
5. As Boethius says, equality precedes every inequality. But there is inequality between Creator and creature. Therefore, we must say that there was some equality in God before this inequality. But there cannot be equality in Him unless there is distinction, for nothing is equal to itself, just as nothing is like itself, as Hilary says Therefore, according to natural reason, we must assign distinction of persons to God.
6. Natural reason comes to the conclusion that there is the greatest joy in God. But "there is not the greatest enjoyment of any good without a companion," as Boethius says. Therefore, by natural reason we can know that there are distinct persons in God, and that by reason of their companionship there is joyful possession of goodness.
7. Natural reason reaches the Creator from the likeness in the creature. But the likeness of the Creator is seen in the creature will reference not only to the essential attributes but also to the properties of the persons. Therefore, by natural reason we can arrive at the proper tics of the persons.
8. Philosophers have had knowledge of God only from natural reason. But some philosophers6 have attained to knowledge of the Trinity. Thus, it is said in Heaven and Earth: "Through this number," three, "we have applied ourselves to admiration of the grandeur of the creator." Therefore.
9. Augustine relates that the philosopher Porphyry taught that there was God the Father and the Son begotten by Him. Augustine also says that he found in certain books of Plato the prologue of St. John’s Gospel, from "In the beginning was the Word" down to, but not including, "The Word was made flesh." The distinction of the persons is clearly shown in these words. Therefore, by natural reason one can reach knowledge of the Trinity.
10. From natural reason, philosophers would have also conceded that God can say something. But to say something in God implies the utterance of the Word and the distinction of persons. Therefore, the trinity of persons can be known by natural reason.
To the Contrary:
1. Hebrews (11:1) says: "Faith is the substance of things to be hoped for, the evidence of things that appear not." But those things 'which are known by natural reason are things that appear. Therefore, since the Trinity belongs to the articles of faith, it seems that it cannot be known by natural reason.
2. Furthermore, Gregory says: "Belief does not have merit when human reason offers evidence for it." But it is in belief especially in the Trinity in which the merit of our faith consists. Therefore, it can not be known by natural reason.
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The trinity of persons is known in two ways. In the first, it is known according to the properties by which the persons are distinguished. When these are known, the Trinity in God is really known. The second way is through essential notes which are appropriated to the persons, as power to the Father, wisdom to the Son, and goodness to the Holy Spirit. But it is impossible to know the Trinity perfectly through notes like these, for, even if in our minds we prescinded from the Trinity, those things would remain in God. But, once the Trinity is presupposed, attributes of this type are appropriated to the persons because of a certain likeness to properties of the persons. With natural knowledge it is possible to know the things which are thus appropriated to the persons, but it is not at all possible to know the proper ties of the persons.
The reason for this is that it is impossible for an action outside the range of the instruments of an agent to proceed from that agent. Thus, it is impossible to build will the art of the blacksmith, for this effect is outside the range of the instruments of the smith. Moreover, as the Commentator says, in us first principles are, as it were, instruments of the agent intellect, and in virtue of its light, natural reason thrives in us. Hence, our natural reason cannot attain to knowledge of any of those things which are outside the range of first principles.
But knowledge of first principles arises from sensible objects, as is clear from the Philosopher. But we cannot proceed from sensible things to knowledge of the properties of the persons in the way one reaches causes from effects. For everything that has the nature of cause in God pertains to His essence, since through His essence He is the cause of things. However, the properties of the persons are relations, through which the persons are related not to creatures, but to each other. Hence, we cannot attain to the properties of the persons by natural knowledge.
Answers to Difficulties:
1. That explanation of the Gloss is taken as referring to the things which are appropriated to the persons, not to the properties.
2. It can be made sufficiently clear from natural reason that intellective power is the first of the powers, but it cannot be shown that this intellective power is generative power. For, since in God the one who understands, the act of understanding, and what is understood is the same thing, natural reason does not force us to say that God, in understanding, begets something distinct from Himself.
3. Every multiplicity supposes some unity and every e supposes univocity, but every equivocal generation does not presuppose univocal generation. Rather, if we follow natural reason, the opposite is true, for equivocal causes are essential causes of a species. Hence, they exert causality on the whole species. But univocal causes are not essential causes of a species, but only in this or that individual. Consequently, a univocal cause does not exert causality will reference to the whole species. Otherwise, it would be its own cause, which is impossible. Therefore, the argument does not follow.
4. That Gloss should be taken of heretical sects which have sprung up in the Church. Accordingly, the sects of the gentiles are not included among them.
5. Even without supposing the distinction of persons, we can affirm equality in God, in so far as we say that His goodness is actual to His wisdom. Another answer can be based on a consideration of the two elements of equality, the cause of the equality and its terms. Unity is the cause of equality, but some number is the cause of other proportions. Hence, according to this consideration, equality precedes in equality, as unity precedes number. But the terms of equality are many. And these are not assumed to be prior to the terms of inequality. Otherwise, duality would have to precede every unity, for equality is first found in duality, but between unity and duality there is in actuality.
6. What Boethius says should be understood of those things which do not have within them perfect goodness, but one needs the support of the other. For this reason, enjoyment is not complete without a companion. But God has within Himself the fullness of joy. Hence, there is no need to posit companionship for the fullness of His enjoyment.
7. Although some aspects of creatures are like the properties of the persons, we cannot conclude from these likenesses that they are found 1n God in the same way. For the things which are distinguished in creatures are in the Creator without distinction.
8. Aristotle did no intend to put the number three in God, but lie Wanted to show the perfection of the number three from the fact that the ancients made use of it in sacrifices and prayers.
9. We should take the words of those philosophers as referring to things appropriated to the persons, not to properties.
10. From natural reason, philosophers have never thought that God speaks in so far as speaking implies distinction of persons, but only in so far as it is applied essentially to God.
Parallel readings: II Sentences, 2, ad 4; 28,, ad Contra Gentiles II, Summa Theol., I, 117, I; De Unit. intell., 5, nn. 50-5 I.
Difficulties:
It seems that only God teaches and should be called a teacher, for 1. In St. Matthew (23:8) we read: "One is your master"; and just before that: "Be not you called Rabbi." On this passage the Gloss comments: "Lest you give divine honor to men, or usurp for your selves what belongs to God." Therefore, it seems that only God is a teacher, or teaches.
2. If a man teaches, he does so only through certain signs. For, even if one seems to teach by means of things, as, when asked what waking is, he walks, this is not sufficient to teach the one who asks, unless some sign be added, as Augustine proves. He does this by showing that there are many factors involved in the same action; hence, one will not know to what factor the demonstration was due, whether to the substance of the action or to some accident of it. Furthermore, one cannot come to a knowledge of things through a sign, for the knowledge of things is more excellent than the knowledge of signs, since the knowledge of signs is directed to knowledge of things as a means to an end. But the effect is not more excellent than its cause.
Therefore, no one can impart knowledge of anything to another, and so cannot teach him.
3. If signs of certain things are proposed to someone by a man, the one to whom they are proposed either knows the things which the signs represent or he does not. If he knows the things, he is not taught them. But if he does not know them, he cannot know the meanings of the signs, since he does not know the things. For a man who does not know what a stone is cannot know what the word stone means. But if he does not know the meaning of the terms, he cannot learn any thing through the signs. Therefore, if a man does nothing else to teach than propose signs, it seems that one man cannot be taught by an other.
4. To teach is nothing else than to cause knowledge in another in some way. But our understanding is the subject of knowledge. Now, sensible signs, by which alone, it would seem, man can be taught, do not reach the intellective part, but affect the senses Only. Therefore, man cannot be taught by a man.
5. If the knowledge is caused by one person in another, the learner either had it already or he did not. If he did not have it already and it was caused in him by another, then one man creates knowledge in another, which is impossible. However, if he had it already, it was present either in complete actuality, and thus it cannot be caused, for what already exists does not come into being, or it was present seminally (secundum rationes seminales). But such seminal principles can not be actualized by any created power, but are implanted in nature by God alone, as Augustine says. So, it remains true that one man can in no way teach another.
6. Knowledge is an accident. But an accident does not change the subject in which it inheres. Therefore, since teaching seems to be nothing else but the transfer of knowledge from teacher to pupil, one cannot teach another.
7. The Gloss, on Romans (10: 17), "Faith then cometh by hearing," says: "Although God teaches man interiorly, the preacher proclaims it exteriorly." But knowledge is caused interiorly in the mind, not exteriorly in the senses. Therefore, man is taught only by God, not by another man.
8. Augustine says: "God alone, who teaches truth on earth, holds the teacher’s chair in heaven, but to this chair another man has the relation which a farmer has to a tree." But the farmer does not make the tree; he cultivates it. And by the same token no man can be said to teach knowledge, but only prepare the mind for it.
9. If man is a real teacher, he must teach the truth. But whoever teaches the truth enlightens the mind, for truth is the light of the mind. If, therefore, man does teach, he enlightens the mind. But this is false, for in the Gospel according to St. John (1:9) we see that it is God who "enlightened every man that cometh into this world." There fore, one man cannot really teach another.
10. If one man teaches another, he must make a potential knower into an actual knower. Therefore, his knowledge must be raised from potency to act. But what is raised from potency to actuality must be changed. Therefore, knowledge or wisdom will be changed. How ever, this is contrary to Augustine, who says: "In coming to a man, wisdom is not itself changed, but changes the man."
11. Knowledge is nothing else but the representation of things in the soul, since knowledge is called the assimilation of the knower to the thing known. But one man cannot imprint the likeness of things in the soul of another. For, thus, he would work interiorly in that man, which God alone can do. Therefore, one man cannot teach another.
12. Boethius says that teaching does no more than stimulate the mind to know. But he who stimulates the understanding to know does not make it know, just as one who incites someone to see will the eyes of the body does not make him see. Therefore, one man does not make another know. And so it cannot properly be said that he teaches him.
13. There is no scientific knowledge without certitude. Otherwise, it is not scientific knowledge but opinion or belief, as Augustine says. But one man cannot produce certitude in another by means of the sensible signs which he proposes. For that which is in the sense faculty is less direct than that which is in the understanding, while certainty is always effected by the more direct. Therefore, one man cannot teach another.
14. The intelligible light and a species are all that are needed for knowledge. But neither of these can be caused in one man by an other. For it would be necessary for a man to create something, since it seems that simple forms like these can be produced only by creation. Therefore, one man cannot cause knowledge in another and, so, cannot teach.
15. As Augustine says, nothing except God alone can give the mind of man its form. But knowledge is a form of the mind. Therefore, only God can cause knowledge in the soul.
16. Just as guilt is in the mind, so is ignorance. But only God cleanses the mind of guilt, according to Isaias (43:25): "I am he that blots out thy iniquities for my own sake." Therefore, God alone cleanses the mind of ignorance. And, so, only God teaches.
17. Since science is certain knowledge, one receives science from him whose words give him certainty. However, hearing a man speak does not give anyone certainty. Otherwise, anything that one person says to another would of necessity be clearly certain. Now, one reaches certitude only when he hears the truth speaking within him. And to be certain, he takes counsel will this interior voice even about those things which he hears from men. Therefore, not man but the truth speaking within, which is God, teaches.
18. No one learns through the words of another those things, which, if asked, he would have answered, even before the other spoke. But even before the teacher speaks, the pupil, upon being questioned, would answer about the matters which the teacher proposes. For he would be taught by the words of the teacher only in so far as he knew that matters were such as the teacher claimed. Therefore, one man is not taught by the words of another.
To the Contrary:
1'. In the second Epistle to Timothy (1:11) we read: "Wherein I am appointed a preacher... and teacher of the gentiles." Therefore, man can be a teacher and can be called one.
2'. In the second Epistle to Timothy (3:14) it is said: "But continue thou in those things which thou has learned, and which have been committed to thee." of this the Gloss says: "From me as from a true teacher." We conclude as before.
3’. In one place in Matthew (23:8,9) we find: "One is your Father" and "One is your master." But the fact that God is our Father does not make it impossible for man truly to be called father. Likewise, the fact that God is our teacher does not make it impossible for man truly to be called teacher,
4'. The Gloss on Romans (10:15), "How beautiful over the mountains..." reads: "They are the feet who enlighten the Church." Now, it is speaking about the Apostles. Since, then, to enlighten is the act of a teacher, it seems that men are competent to teach.
5'. As is said in the Meteorology, each thing is perfect when it can generate things like itself. But scientific knowledge is a kind of perfect knowledge. Therefore, a man who has scientific knowledge can teach another.
6’. Augustine says that just as the earth was watered by a fountain before the coming of sin, and after its coming needed ram from the clouds above, so also the human mind, which is represented by the earth, was made fruitful by the fountain of truth before the coming of sin, but after its coming it needs the teaching of others as ram coming down from the clouds. Therefore, at least since sin came into the world, man is taught by man.
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There is the same sort of difference of opinion on three issues: on the bringing of forms into existence, on the acquiring of virtues, and on the acquiring of scientific knowledge.
For some have said that all sensible forms come from an external agent, a separated substance or form, which they call the giver of forms or agent intelligence, and that all that lower natural agents do is prepare the matter to receive the form. Similarly, Avicenna says that our activity is not the cause of a good habit, but only keeps out its opposite and prepares us for the habit so that it may come from the substance which perfects the souls of men. This is the agent intelligence or some similar substance.
They also hold that knowledge is caused in us only by an agent free of matter. For this reason Avicenna holds that the intelligible forms flow into our mind from the agent intelligence.
Some have held the Opposite opinion, namely, that all three of those are embodied in things and have no external cause, but are only brought to light by external activity. For some have held that all natural forms are in act, lying hidden in matter, arid that a natural agent does nothing but draw them from concealment out into the open. In like manner, some hold that all the habits of the virtues are implanted in us by nature. And the practice of their actions removes the obstructions which, as it were, hid these habits, just as rust is re moved by filing so that the brightness of the iron is brought to light. Similarly, some also have said that the knowledge of all things is con-created will the soul and that through teaching and the external helps of this type of knowledge all that happens is that the soul is prompted to or consider those things which it knew previously. Hence, they say that learning is nothing but remembering. But both of these positions lack a reasonable basis. For the first opinion excludes proximate causes, attributing solely to first causes all effects which happen in lower natures. In this it derogates from the order of the universe, which is made up of the order and connection of causes, since the first cause, by the pre-eminence of its goodness, gives other beings not only their existence, but also their existence as causes. The second position, too, falls into practically the same difficulty. For, since a thing which removes an obstruction is a mover only accidentally, as is said in the Physics, if lower agents do nothing but bring things from concealment into the open, taking away the obstructions which concealed the forms and habits of the virtues and the sciences, it follows that all lower agents act only accidentally.
Therefore, in all that has been said we ought to hold a middle Position between these two, according to the teaching of Aristotle. For natural forms pre-exist in matter not actually, as some have said, but only in potency. They are brought to actuality from this state of potency through a proximate external agent, and not through the first agent alone, as one of the opinions maintains. Similarly, according to this opinion of Aristotle, before the habits of virtue are completely formed, they exist in us in certain natural inclinations, which are the beginnings of the virtues. But afterwards, through practice in their actions, they are brought to their proper completion.
We must give a similar explanation of the acquisition of knowledge. For certain seeds of knowledge pre-exist in us, namely, the first concepts of understanding, which by the light of the agent intellect are immediately known through the species abstracted from sensible things. These are either complex, as axioms, or simple, as the notions of being, of the one, and so on, which the understanding grasps immediately. In these general principles, however, all the consequences are included as in certain seminal principles. When, therefore, the mind is led from these general notions to actual knowledge of the particular things, which it knew previously in general and, as it were, potentially, then one is said to acquire knowledge.
We must bear in mind, nevertheless, that in natural things something can pre-exist in potency in two ways. In one, it is in an active and completed potency, as when an intrinsic principle has sufficient power to flow into perfect act. Healing is an obvious example of this, for the sick person is restored w health by the natural power within him. The other appears in a passive potency, as happens when the internal principle does not have sufficient power to bring it into act. This is clear when air becomes fire, for this cannot result from any power existing in the air.
Therefore, when something pre-exists in active completed potency, the external agent acts only by helping the internal agent and providing it will the means by which it can enter into act. Thus, in healing the doctor assists nature, which is the principal agent, by strengthening nature and prescribing medicines, which nature uses as instruments for healing. On the other hand, when something pre-exists only in passive potency, then it is the external agent which is the principal cause of the transition from potency to act. Thus, fire makes actual lire of air, which is potentially fire.
Knowledge, therefore, pre-exists in the learner potentially, not, however, in the purely passive, but in the active, sense. Otherwise, man would not be able to acquire knowledge independently. There fore, as there are two ways of being cured, that is, either through the activity of unaided nature or by nature will the aid of medicine, so also there are two ways of acquiring knowledge. In one way, natural reason by itself reaches knowledge of unknown things, and this way is called discovery; in the other way, when someone else aids the learner’s natural reason, and this is called learning by instruction.
In effects which are produced by nature and by art, art operates in the same way and through the same means as nature. For, as nature heals one who is suffering from cold by warming him, so also does the doctor. Hence, art is said to imitate nature. A similar thing takes place in acquiring knowledge. For the teacher leads the pupil to knowledge of things he does not know in the same way that one directs himself through the process of discovering something he does not know.
Now, in discovery, the procedure of anyone who arrives at the knowledge of something unknown is to apply general self-evident principles to certain definite matters, from these to proceed to particular conclusions, and from these to others. Consequently, one per- son is said to teach another inasmuch as, by signs, he manifests to that other the reasoning process which he himself goes through by his own natural reason. And thus, through the instrumentality, as it were, of what is told him, the natural reason of the pupil arrives at a knowledge of the things which he did not know. Therefore, just as the doctor is said w heal a patient through the activity of nature, so a man is said to cause knowledge in another through the activity of the learner’s own natural reason, and this is teaching. So, one is said to teach an other and be his teacher. This is what the Philosopher means when he says: "Demonstration is a syllogism which makes someone know." But, if someone proposes w another things which are not included in self-evident principles, or does not make it clear that they are in c he will not cause knowledge in the other but, perhaps, opinion or faith, although even this is in some way caused by inborn first principles, for from these self-evident principles he realizes that what necessarily follows from them is to be held will certitude, and that what is contrary to them is to be rejected completely, and that assent may be given to or withheld from whatever neither follows necessarily from nor is contrary to self-evident principles. Now, the light of reason by which such principles are evident to us is implanted in us by God as a kind of reflected likeness in us of the uncreated truth. So, since all human teaching can be effective only in virtue of that light, it is obvious that God alone teaches interiorly and principally, just as nature alone heals interiorly and principally. Nevertheless, both to heal and to teach can still be used in a proper sense in the way we have explained.
Answers to Difficulties:
1. Since our Lord had ordered the disciples not w be called teachers, the Gloss explains how this prohibition is to be understood, lest it be taken absolutely. For we are forbidden to call man a teacher in this sense, that we attribute to him the pre-eminence of teaching, which belongs to God. It would be as if we put our hope in the wisdom of men, and did not rather consult divine truth about those things which we hear from man. And this divine truth speaks in us through the impression of its likeness, by means of which we can judge of all things.
2. Knowledge of things is not produced in us through knowledge of signs, but through knowledge of things more certain, namely, principles. The latter are proposed to us through signs and are applied to other things which were heretofore unknown to us simply, although they were known to us in some respect, as has been said. For knowledge of principles produces in us knowledge of conclusions; knowledge of signs does not.
3. To some extent we know the things we are taught through signs, and w some extent we do not know them. Thus, if we are taught what man is, we must know something about him beforehand, namely, the meaning of animal, or of substance, or at least of being itself, which last concept cannot escape us. Similarly, if we are taught a certain conclusion, we must know beforehand what the subject and predicate are. We must also have previous knowledge of the principles through which the conclusion is taught, for "all teaching comes from pre-existing knowledge," as is said in the Posterior Analytics. Hence, the argument does not follow.
4. Our intellect derives intelligible likenesses from sensible signs which are received in the sensitive faculty, and it uses these intelligible forms to produce in itself scientific knowledge. For the signs are not the proximate efficient cause of knowledge, but reason is, in its passage from principles to conclusions, as has been said.
5. In one who is taught, the knowledge did not exist in complete actuality, but, as it were, in seminal principles, in the sense that the universal concepts which we know naturally are, as it were, the seeds of all the knowledge which follows. But, although these seminal principles are not developed to actuality by any created power, as though they were infused by a created power, that which they have in a primitive way and virtually can develop into actuality by means of the activity of a created power.
6. We do not say that a teacher communicates knowledge w the pupil, as though the knowledge which is in the teacher is numerically the same as that which arises in the pupil. It is rather that the knowledge which arises in the pupil through teaching is similar to that which is in the teacher, and this was raised from potency into act, as has been said.
7. As the doctor is said to cause healing, although he works exteriorly, while nature alone works interiorly, so man is said to teach the truth, although lie declares it exteriorly, while God teaches interiorly.
8. When Augustine proves that only God teaches, he does not in- tend to exclude man from teaching exteriorly, but intends to say that God alone teaches interiorly.
9. Man can truly be called a true teacher inasmuch as lie teaches the truth and enlightens the mind. This does not mean, however, that lie endows the mind will light, but that, as it were, he co-operates will the light of reason by supplying external help to it to reach the perfection of knowledge. This is in accordance will Ephesians (3: 8-9): "To me, the least of all the saints, is given this grace...to enlighten all men…"
10. Wisdom is twofold, created and uncreated. Man is said to be endowed will both and to improve himself by advancing in them. Uncreated wisdom, however, cannot be changed in any way, whereas in us created wisdom can be changed for some extrinsic reason, toughly not by reason of anything intrinsic to it. We can consider this capacity for change in two ways. In one way, according to the relation which it has to eternal things, and in this way it is entirely unchangeable. In the other, according to the existence which it has in the subject, it is changed for some extrinsic reason when the subject which has wisdom in potency is changed into a subject having it in ace. For the intelligible forms in which wisdom consists are both likenesses of things and forms perfecting the understanding.
11. In the pupil, the intelligible forms of which knowledge received through teaching is constituted are caused directly by the agent intellect and mediately by the one who teaches. For the teacher sets before the pupil signs of intelligible things, and from these the agent intellect derives the intelligible likenesses and causes them to exist in the possible intellect. Hence, the words of the teacher, heard or seen in writing, have the same efficacy in causing knowledge as things which are outside the soul. For from both the agent intellect receives intelligible likenesses, although the words of the teacher are more proximately disposed to cause knowledge than things outside the soul, in so far as they are signs of intelligible forms.
12. Intellectual and bodily sight are not alike, for bodily sight is not a power which compares, so that among its objects it can proceed from one to another. Rather, all the objects of this sight can be seen as soon as it turns to them. Consequently, anyone who has the power of sight can look at all visible things, just as one who has a habit of knowledge can turn his attention to the things which he knows habitually. There fore, the seeing subject needs no stimulus from another to see some thing, unless, perhaps, someone else directs the subject’s attention to some object by pointing it out or doing something of the sort.
But, since the intellective power can compare, it proceeds from some things to others. As a result, it does not have the same relation to all intelligible objects of consideration. Rather, the mind sees certain things immediately, those which are self-evident, in which are contained certain other things which it can understand only by using reason to unfold those things which are implicitly contained in principles. Thus, before the mind has the habit, it is not only in accidental potency to know these things, but also essential potency. For the mind needs a mover to actualize it through teaching, as is said in the Physics. But a man who already knew something habitually would not need this. Therefore, the teacher furnishes the pupil’s intellect will a stimulus to knowledge of the things which he teaches, as an indispensable mover, bringing the intellect from potentiality to actuality. But one who shows some thing to bodily sight prompts it to action as a nonessential mover. And one who has the habit of knowledge can in this way receive a stimulus from someone to consider something.
13. The whole certainty of scientific knowledge arises from the certainty of principles. For conclusions are known will certainty when they are reduced to the principles. Therefore, that something is known will certainty is due to the light of reason divinely implanted within us, by which God speaks within us. It comes from man, teaching from without, only in so far as, teaching us, he reduces conclusions to the principles. Nevertheless, we would not attain the certainty of scientific knowledge from this unless there were within us the certainty of the principles to which the conclusions are reduced.
14. Man, teaching from without, does not infuse the intelligible light, but he is in a certain sense a cause of the intelligible species, in so far as he offers us certain signs of intelligible likenesses, which our understanding receives from those signs and keeps within itself.
15. When it is said that nothing but God can form the mind, this is understood of its basic form, without which mind would be considered formless, no matter what other forms it had. This is the form by which it turns toward the Word and clings to Him. It is through this alone that rational nature is called formed, as is clear from Augustine.
16. Guilt is in the affections, on which only God can make an impression, as will appear later. But ignorance is in the understanding, on which even a created power can make an imprint. For the agent intellect impresses the intelligible species on the possible intellect, and through the mediation of this latter, scientific knowledge is caused in our soul by sensible things and by the teaching of man, as has been said.
17. One has the certainty of scientific knowledge, as has been said, from God alone, who has given us the light of reason, through which we know principles. It is from these that the certainty of scientific knowledge arises. Nevertheless, scientific knowledge can in a certain sense be caused in us by man, as has been said.
18. Before the teacher speaks, the pupil would, if asked, answer about the principles through which he is taught, but not about the conclusions which someone is teaching him. Hence, he does not learn the principles from the teacher, but only the conclusions.
Parallel readings; Summa Theol., I, 117, 1, ad. See also parallels given for preceding article.
Difficulties:
It seems that he can, for
1. An activity should be ascribed more to the principal cause than to the instrumental cause. But in us the agent intellect is, as it were, the principal cause of the knowledge which is produced in us. But man who teaches another is, as it were, an instrumental cause, furnishing the agent intellect will the instruments by means of which it causes knowledge. Therefore, the agent intellect is more the teacher than another man. If, then, because of what a speaker says we call him the teacher of the one who hears him, the hearer should in a much fuller sense be called his own teacher because of the light of the agent intellect.
2. One learns something only in so far as he acquires certain knowledge. But such certitude is in us by reason of the principles which are naturally known in the light of the agent intellect. Therefore, the agent intellect is especially fitted to teach. We conclude as before.
3. To teach belongs more properly to God than to man. Hence, it is said in Matthew (23:8): "For one is your master." But God teaches us in so far as He gives us the light of reason, by means of which we can judge about everything. Therefore, we should attribute the activity of teaching especially to that light. The same conclusion follows as before.
4. It is more perfect to learn something through discovery than to learn it from another, as is clear in the Ethics. If, therefore, a man is called a teacher in virtue of that manner of acquiring knowledge by which one learns from another so that the one is called the teacher of the other, he should will much greater reason be called a teacher in virtue of the process of acquiring knowledge through discovery, and so be called his own teacher.
5. Just as one is inspired to virtue by another and by himself, so also he gets to know something by discovering for himself and by learning from another. But those who attain to works of virtue will out having another as an instructor or a lawgiver are said to be a law unto themselves, according to Romans (2: 14): "For when the Gentiles, who have not the law, do by nature those things that are of the law...they are a law to themselves." Therefore, the man who ac quires knowledge by himself ought also to be called his own teacher.
6. The teacher is a cause of knowledge as the doctor is a cause of health, as has been said. But a doctor heals himself. Therefore, one can also teach oneself.
To the Contrary:
1'. The Philosopher says that it is impossible for one who is teaching to learn. For the teacher must have knowledge and the learner must not have it. Therefore, one cannot teach himself or be called his own teacher.
2’. The office of teacher implies a relation of superiority, just as dominion does. But relationships of this sort cannot exist between a person and himself. For one is not his own father or master. There fore, neither can one be called his own teacher.
De veritate EN 104