ARTICLE I

The Question Treats of the Teacher, and in the First Article We Ask: CAN A MAN OR ONLY GOD TEACH AND BE CALLED TEACHER?

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 yourselves 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 walking 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 anything through the signs. Therefore, if a man does nothing else to teach than propose signs, it seems that one man cannot be taught by another.

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 cannot 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 "enlighteneth every man that cometh into this world." Therefore, 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. However, 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 with 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 another. 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 with 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 rain 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 rain coming down from the clouds. Therefore, at least since sin came into the world, man is taught by man.

REPLY:

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, and 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 removed 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 with 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 recall 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 to 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 with 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 fire 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. Therefore, as there are two ways of being cured, that is, either through the activity of unaided nature or by nature with 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 person 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 to 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 another 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 to another things which are not included in self-evident principles, or does not make it clear that they are included, 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 with 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 to 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 to 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 to 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 he declares it exteriorly, while God teaches interiorly.

8. When Augustine proves that only God teaches, he does not intend 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 he teaches the truth and enlightens the mind. This does not mean, however, that he endows the mind with light, but that, as it were, he co-operates with the light of reason by supplying external help to it to reach the perfection of knowledge. This is in accordance with 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 with 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, though 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 act. 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. Therefore, the seeing subject needs no stimulus from another to see something, 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 with 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 with certainty when they are reduced to the principles. Therefore, that something is known with 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.