ARTICLE I

The Question Treats of Higher and Lower Reason, and in the First Article We Ask: ARE UNDERSTANDING AND REASON DIFFERENT POWERS

IN MAN?

Difficulties:

It seems that they are, for

1. In Spirit and Soul we read: "When we want to rise from lower to higher things, first, senses come to our aid; then, imagination; then, reason; then, understanding; then, intelligence; and, in the highest place, there is wisdom, which is God Himself." But imagination and sense are different powers. Therefore, reason and understanding are, too.

2. As Gregory says, man has something in common with every creature, and for this reason is man called all creation. However, that by which man has something in common with plants is a power of the soul, the vegetative, which is distinct from reason, the proper power of man, as man. The same is true for the senses, by which he has something in common with brute animals. Therefore, with equal reason, his understanding, which he has in common with angels, who are above man, is a power different from reason, which is proper to the human race, as Boethius says.

3. Just as the perceptions of the proper senses terminate at the common sense, which makes judgments concerning them, so the discourse of reason terminates at understanding, so that judgment may be made about the things which reason has compared. For man judges of the things which reason compares when by analysis he reaches principles which are the objects of understanding. For this reason the art of judging is called analytical. Therefore, as common sense is a different power from proper sense, so understanding is different from reason.

4. To comprehend and to judge are acts requiring different powers, as is clear in proper and common sense. For common sense judges about the things which proper sense perceives. But, as is said in Spirit and Soul: "Whatever sense perceives, imagination represents, thought forms, genius investigates, reason judges, memory retains, and intelligence comprehends." Therefore, reason and intelligence are different powers.

5. That which is simply composite relates to simple act in the same way as that which is altogether simple relates to composite act. But the divine intellect, which is simple in every way, has no composite act, but only the most simple act. Therefore, our reason, which is composite, inasmuch as it compares, does not have a simple act. But the act of understanding is simple, "for it is understanding of things indivisible," as is said in The Soul. Therefore, understanding and reason are not one power.

6. According to the Commentator and the Philosopher, the rational soul knows itself through a likeness. "The mind, however, in which the image resides, knows itself through itself," according to Augustine. Therefore, reason and mind, or understanding, are not the same.

7. Powers are differentiated according to acts, and acts according to objects. But the objects of reason and understanding differ very greatly. For, as is said in Spirit and Soul: "The soul perceives bodies by sense, likenesses of bodies by imagination, natures of bodies by reason, created spirit by understanding, and uncreated spirit by intelligence." But bodily nature differs very greatly from created spirit. Therefore, understanding and reason are different powers.

8. Boethius says: "Sense, imagination, reason, and intelligence each look on man in a different way. Sense sees figure embodied in given matter, whereas imagination judges of figure alone without matter. Reason, in its turn, transcends imagination, examining with general consideration the species which exists in singular things. Moreover, the eye of intelligence has a more lofty existence, for intelligence goes beyond the scope of the universe and by sheer force of mind surveys simple form itself." Therefore, just as imagination is a power different from sense, since imagination considers form outside of matter, and sense sees it embodied in matter, so intelligence, which considers form absolutely, is a power different from reason, which studies the general form as it exists in individual things.

9. Boethius says: "As reasoning is related to understanding, as that which is produced, to that which exists, as time to eternity, and as the circle to its center point, so the changeable series of fate is related to the stable simplicity of providence." But it is plain that there is an essential difference between providence and fate, between the circle and its center, between time and eternity, and between generation and existence. Therefore, reason, too, is essentially different from understanding.

10. As Boethius says: "Reason belongs to the human race alone, as intelligence belongs only to the divine." But the divine and the human cannot both share in the one essence of power. Therefore, they are not one power.

11. The order of powers follows the order of acts. But to receive something absolutely, which seems to belong to understanding, is prior to comparison, which belongs to reason. Therefore, understanding is prior to reason. But nothing is prior to itself. Therefore, understanding and reason are not the same power.

12. It is one thing to consider the entity of a thing absolutely, and another to consider it as in this thing. The human soul exercises both of these considerations. Therefore, in the human soul there must be two powers, one to know the absolute entity, which is understanding, and another to know the entity in something else, which seems to be reason. We conclude as before.

13. In Spirit and Soul we read: "Reason is the sight of the mind by which it distinguishes good and evil, chooses virtues, and loves God." These things seem to belong to the affections which are a different power from the understanding. Therefore, reason, too, is a different power from the understanding.

14. The rational is distinguished from the concupiscible and irascible. But the irascible and concupiscible belong to the appetites. Therefore, reason does, also. We conclude as before.

15. The Philosopher says: "The will is in the rational part." But it is distinguished from understanding. We conclude as before.

To the Contrary:

1'. Augustine seems to say the opposite when he says: "We arrive at the image of God, which is man, in that by which he surpasses other animals, that is, in reason or intelligence. And whatever else there is of the rational or intellectual soul can be said to belong to that thing which is called mind or mental life." From this it seems that he takes reason and intelligence as the same thing.

2'. In Augustine (and in the Gloss on Ephesians [4:23], "And be renewed in the spirit of your mind,") we read: "We should understand that man is made in the image of God in that by which he surpasses irrational animals." But this is reason itself, mind, intelligence, or whatever other name fits it better. Therefore, it seems that reason and understanding are for Augustine different names for the same power.

3'. Augustine says: "The image of that nature than which no nature is better should be sought and found in us in that than which our nature, also, has nothing better." But the image of God is in us in the higher part of reason, as is said in The Trinity. Therefore, there is no other power in man better than reason. But, if intelligence or understanding were different from reason, they would be above reason, as is clear from the citations from Boethius and Spirit and Soul mentioned above. Therefore, in man, understanding is not a different power from reason.

4'. The more immaterial a power is, the more it can extend to many things. But common sense, which is a material power, institutes comparisons of proper sensibles by distinguishing them from one another, and also has knowledge of them separately. Otherwise, it would not be able to distinguish one from another, as is proved in The Soul. Therefore, it is much more certain that reason, which is a more immaterial power, can not only compare, but also perceive things separately, a function which belongs to understanding. Thus, understanding and reason do not seem to be different powers.

5'. As is said in Spirit and Soul: "The mind, capable of receiving everything, and stamped with the likeness of all things, is said to be the soul and to be a nature with a certain power and natural dignity." But that which designates the whole soul should not be distinguished from some power of the soul. Therefore, the mind, which is a power of the soul, should not be distinguished from reason. Similarly, understanding, which seems to be the same thing as mind, should not be distinguished from it.

6'. There is a double composition in the activity of the human soul. There is one by which it joins and divides predicate and subject, by forming propositions. The other is that by which it joins by comparing principles with conclusions. In the first composition the same power of the human soul apprehends the simple things, that is, predicate and subject, through their quiddities, and forms a proposition by joining them. For both of these are attributed to the possible intellect, according to The Soul. Therefore, with like reason there will be one power which grasps principles, a function which belongs to understanding, and which orders principles to conclusions, a function which belongs to reason.

7'. In Spirit and Soul we read: "The soul is an intellectual or rational spirit." From this it seems that reason is the same as understanding.

8'. Augustine says: "As soon as something arises which is not common to us and animals, it belongs to reason." This same thing also belongs to understanding, according to the Philosopher. Therefore, reason and understanding are the same.

9'. Difference of objects in their accidental qualities does not indicate diversity of faculties. For a colored man and a colored stone are perceived by the same sensitive faculty, since it is incidental to the sensible thing in so far as it is a sensible thing, to be a man or a stone. But the objects which are ascribed to reason and understanding in Spirit and Soul, that is, "created spirit" and "corporeal nature," do not differ, but agree, in their essential character as object of knowledge. For, just as a created incorporeal spirit is intelligible because it is immaterial, so, too, bodily natures are objects of understanding only in so far as they are separated from matter. Thus, both of these, in so far as they are known, share in one character of cognoscibility, the character of immateriality. Therefore, reason and understanding are not different powers.

10'. Every power that compares two things with each other must have knowledge of each separately. Hence, the Philosopher proves that in us there must be one power which knows "white and sweet" because we can distinguish between them. But, just as one who distinguishes between different things relates them to each other, so also, he who compares them relates one to the other. Therefore, it also belongs to the power which compares, namely, reason, to know something separately, which is an activity of understanding.

11'. It is more noble to compare than to be compared, just as it is more noble to act than to be acted upon. But a thing is understood and compared through the same thing. Therefore, the soul, also, understands and compares through the same thing. Therefore reason and understanding are the same.

12'. One habit does not exist in different powers. But it is possible for us to compare and perceive something separately by the same habit. Thus, faith, which perceives a thing separately, in so far as it clings to first truth, also compares, to the extent that by a sort of reasoning it sees first truth mirrored in creatures. Therefore, it is the same power which compares and which perceives something separately.

REPLY:

For a clear understanding of this question we must investigate the difference between reason and understanding. We must bear in mind that, according to Augustine, just as among corporeal substances there is an orderly disposition, according to which some are said to be higher than others and have control over them, so, too, among spiritual substances there is a certain orderly disposition.

The difference between higher and lower bodies seems to lie in this, that the lower bodies reach the perfection of their existence through the movement of generation, change, and increase. This is obvious in stones, plants, and animals. Higher bodies, however, have the perfection of their existence according to their substance, power, quantity, and figure immediately in their very beginning without any movement. This is obvious in the sun, moon, and stars. The perfection of spiritual nature, however, lies in the cognition of truth. Consequently, there are some higher spiritual substances which immediately in the beginning receive knowledge of truth without any movement or reasoning by a sudden or simple reception. This is the case with angels, and for this reason they are said to have godlike understanding. There are, also, lower spiritual substances, which can arrive at perfect knowledge of truth only through a certain movement, in which they go from one thing to another, in order to reach knowledge of things unknown through those which are known. This is proper to human souls. And this is why angels are called intellectual substances, whereas souls are called rational substances.

Understanding seems to indicate simple and absolute knowledge. And one is said to understand (intelligere) because in some sense he reads (legit) the truth within (intus) the very essence of the thing. Reason, on the other hand, denotes a transition from one thing to another by which the human soul reaches or arrives at knowledge of something else. For this reason, Isaac says that reasoning is the progress of the cause to the thing caused.

Now, all movement proceeds from what is at rest, as Augustine says. For rest is the term of motion, as is said in the Physics. Thus, movement is related to rest as to its source and its term, as is reason, also, which is related to understanding as movement to rest and generation to existence, as is clear from the citation from Boethius given above. It is related to understanding as to its source and its term. It is related to it as its source because the human mind could not move from one thing to another unless the movement started from some simple perception of truth, and this perception is understanding of principles. Similarly, the movement of reason would not reach anything certain unless there were an examination of that which it came upon through discursive movement of the mind. This examination proceeds to first principles, the point to which reason pursues its analysis. As a result, we find that understanding is the source of reasoning in the process of discovery and its term in that of judging.

Consequently, although the knowledge proper to the human soul takes place through the process of reasoning, nevertheless, it participates to some extent in that simple knowledge which exists in higher substances, and because of which they are said to have intellective power. This is in keeping with the rule which Dionysius gives, that divine wisdom "always joins the limits of higher things to the beginnings of the lower things." This is to say that the lower nature at its highest point reaches something of that which is lowest in the higher nature.

Dionysius also points out this difference between angels and souls when he says: "From divine wisdom the intellectual powers of angelic minds have pure and good acts of understanding, not gathering divine knowledge from divisible things or the senses or extended discussions, but uniformly understanding the intelligible things of God." Later, he adds about souls: Therefore, because of the divine wisdom, souls have rationality, too, "but spread out, circling about the truth of existing things, by the diversity of division falling short of unitive minds. But through the reduction of many things to one by reflection souls are held worthy of acts of understanding equal to those of angels, in so far as this is proper and possible to souls." He says this because that which belongs to a higher nature cannot exist in a lower nature perfectly, but only according to a slight participation. Thus, in sensitive nature there is not reason, but only a participation of reason inasmuch as brute animals have a kind of natural prudence, as appears plainly in the Metaphysics.

However, what is thus shared is not held as a possession, that is, as something perfectly within the power of the one who has it. In this sense it is said in the Metaphysics that knowledge of God is a divine and not a human possession. As a result, no power is assigned for that which is held in this manner. Thus, brute animals are not said to have any reason, although they share to some degree in prudence. But this exists in them according to a natural [instinctive] judgment. Similarly, there is no one special power in man through which he gets knowledge of truth simply, absolutely, and without movement from one thing to another. Such perception of truth is in man through a natural habit, which is called understanding of principles. Accordingly, there is no power in man separate from reason which is called understanding. Rather, reason itself is called understanding because it shares in the intellectual simplicity, by reason of which it begins and through which it terminates its proper activity. For this reason, the proper act of understanding is attributed to reason in Spirit and Soul. And that which is proper to reason is given as the act of reason, where it says that reason is the sight of the soul by which it looks at the true through itself; reasoning, however, is the investigation of reason.

Even if we conceded that it were properly and completely fitting for us to have some power for simple perception and independent knowledge of the truth which is in us, it would not be another power than reason. This is clear from what follows, for, according to Avicenna, different acts indicate a difference of powers only when they cannot be referred to the same principle. Thus, in physical things, to receive and to retain are not reduced to the same principle, but the former is referred to the wet and the latter to the dry.

Therefore, imagination, which retains bodily forms in a physical organ, is a different power from sense, which receives these forms through a physical organ. However, the act of reason, which is to move from one thing to another, and the act of understanding, which is to grasp truth directly, are related to each other as generation to existence and movement to rest. But to be at rest and to be moved are reduced to the same principle in all things in which both are found. For a thing is moved to a place through the same nature through which it rests in a place. And that which is at rest and that which is moved are like perfect and imperfect. Hence, the power which moves in thought from one thing to another and the power that perceives truth are not different powers, but one power which knows truth absolutely, in so far as it is perfect, and needs movement in thought from one thing to another, in so far as it is imperfect.

Consequently, in us, reason, taken strictly, can in no way be a power different from understanding. But, sometimes, the cogitative power, which is a power of the sensitive soul, is called reason, since it makes comparisons between individual forms, just as reason, properly so called, does between universal forms, as the Commentator says. This has a definite organ, the middle cell of the brain. And this reason is, without doubt, a power different from understanding. But we are not speaking of this at present.

Answers to Difficulties:

1. Spirit and Soul is not authentic and is not believed to belong to Augustine. Nevertheless, in support of what it says, one can say that in what he said the author did not intend to distinguish powers of the soul, but to show the different steps by which the soul advances in knowledge, so that through the senses it knows forms in matter, through imagination it knows accidental forms without matter, but with the conditions of matter. Through reason it knows the essential form of material things without the individual matter. From this it rises higher in the possession of some kind of knowledge of created spirits, and, thus, is said to have understanding, since spirits of this sort have prior knowledge of substances which exist entirely without matter. From this it goes even further to some knowledge of God himself, and thus is said to have intelligence, which gives the proper name of the act of understanding, since to know God is proper to God, whose understanding is His intelligence, that is, His act of understanding.

2. As Boethius says: "The higher power embraces the lower, but the lower in no way rises to the higher." Hence, a higher nature can do fully what belongs to the lower, but it cannot perform fully what belongs to one still higher. Therefore, the nature of the rational soul has powers for the things that belong to sensitive and vegetative nature, but not for the things that belong to the intellectual nature which exists above it.

3. Since, according to the Philosopher, common sense perceives all sensibles, it must be drawn to them according to one common character; otherwise it would not have one object of its own. None of the proper senses can attain to this common character of object. Reason, on the other hand, reaches direct understanding as its term when, for example, the movement of reason concludes at science. Consequently, it is not necessary that in us understanding be a different power from reason, as common sense differs from the proper senses.

4. To judge is not a property of reason through which it can be distinguished from understanding. For understanding, too, judges that this is true and that false. But judgment and the comprehension of intelligence are referred to reason to this extent, that in us judgment commonly takes place through analysis into principles, whereas direct comprehension of truth takes place through understanding.

5. That which is altogether simple completely lacks composition. But simple things are preserved in composite things. Thus it is that what belongs to the composite, in so far as it is composite, is not found in what is simple. Accordingly, a simple body does not have taste, which follows upon mixture. But compound bodies have the things which belong to simple bodies, although in an inferior manner. Thus, hot and cold, light and heavy, are found in compound bodies. Therefore, there is no composition in the divine understanding, which is entirely simple. But our reason, although it is composite, can enter upon simple act and composite act, either as it puts subject and predicate together or joins principles in order to arrive at a conclusion, because there is something of the nature of the simple in it, as the model is in its image.

Therefore, in us, it is the same faculty which knows the simple quiddities of things, which forms propositions, and which reasons. The last of these is proper to reason, as reason; the other two can also belong to understanding, as understanding. Hence, the second is found in angels, since they know through many species, but only the first is in God, who understands all things, simple and composite, by knowing His own essence.

6. In some sense the soul knows itself through itself, inasmuch as to know is to possess in itself knowledge of itself, and in some sense it knows itself through a species of an intelligible object, in so far as knowing implies thinking and distinguishing of self. Thus, the Philosopher and Augustine are speaking of the same thing. Hence, the conclusion does not follow.

7. Such difference of objects cannot diversify faculties, because it is based on accidental differences. This has been proved above. Bodily nature is thus given as the object of reason, because it is proper to human knowledge to begin from sense and phantasm. For this reason, the gaze of our understanding, which is properly called reason, inasmuch as reason is proper to the human race, first fastens on the natures of sensible things. From this it rises higher in its knowledge of created spirit, which is more within its competence according to its participation of higher nature than according to that which is proper and perfectly fitted to it.

8. Boethius intends intelligence and reason to be different cognoscitive powers, not of the same subject, but of different subjects. Thus, he intends reason to belong to man, and so he says that it knows general forms existing in individual things, since human knowledge properly concerns forms drawn from the senses. Moreover, he intends intelligence to belong to higher substances, which in their first glance apprehend completely immaterial forms. Accordingly, he does not intend that reason should ever reach that which belongs to intelligence, since we can never in the weakness of this knowledge attain to sight of the quiddities of immaterial substances. However, we will do this in heaven when we will be made godlike through glory.

9. In so far as reason and understanding are in different beings, they are not the same power. But the present question concerns them in so far as both exist in man.

10. This reasoning proceeds correctly for acts which belong to different powers. But one power may have different acts, one of which is before the other. Thus the act of possible intellect is to understand essence and to form propositions.

11. The soul knows both, but through the same power. Nevertheless, it seems proper to the human soul, as rational, to know being in this thing. But to know being simply seems to belong rather to the higher substances, as is clear from the passage cited above.*

12. To love God and to choose virtues are attributed to reason, not because they belong to it directly, but in so far as the will is attracted to God as its end, and to virtues as means to that end by the judgment of reason. It is in this way, too, that rational is distinguished from the irascible and the concupiscible, since we are inclined to action by the judgment of reason or by passion, which is in the irascible or concupiscible parts. The will is also said to be in reason inasmuch as it is in the rational part of the soul, just as memory is said to be in sense since it is in the sensitive part of the soul, and not because it is the same power.

13-14. The solution to the thirteenth and fourteenth difficulties is clear from what has been said.