Summa Th. I-II EN Qu.35 a.6
Objection: 1. It would seem that sorrow is to be shunned more than pleasure is to be sought. For Augustine says (Questions. 83, qu. 63): "There is nobody that does not shun sorrow more than he seeks pleasure." Now that which all agree in doing, seems to be natural. Therefore it is natural and right for sorrow to be shunned more than pleasure is sought.
2. Further, the action of a contrary conduces to rapidity and intensity of movement: for "hot water freezes quicker and harder," as the Philosopher says (Meteor. i, 12). But the shunning of sorrow is due to the contrariety of the cause of sorrow; whereas the desire for pleasure does not arise from any contrariety, but rather from the suitableness of the pleasant object. Therefore sorrow is shunned more eagerly than pleasure is sought.
3. Further, the stronger the passion which a man resists according to reason, the more worthy is he of praise, and the more virtuous: since "virtue is concerned with the difficult and the good" (Ethic. ii, 3). But the brave man who resists the movement of shunning sorrow, is more virtuous than the temperate man, who resists the movement of desire for pleasure: since the Philosopher says (Rhet. ii, 4) that "the brave and the just are chiefly praised." Therefore the movement of shunning sorrow is more eager than the movement of seeking pleasure.
On the contrary Good is stronger than evil, as Dionysius declares (Div. Nom. iv). But pleasure is desirable for the sake of the good which is its object; whereas the shunning of sorrow is on account of evil. Therefore the desire for pleasure is more eager than the shunning of sorrow.
I answer that The desire for pleasure is of itself more eager than the shunning of sorrow. The reason of this is that the cause of pleasure is a suitable good; while the cause of pain or sorrow is an unsuitable evil. Now it happens that a certain good is suitable without any repugnance at all: but it is not possible for any evil to be so unsuitable as not to be suitable in some way. Wherefore pleasure can be entire and perfect: whereas sorrow is always partial. Therefore desire for pleasure is naturally greater than the shunning of sorrow. Another reason is because the good, which is the object of pleasure, is sought for its own sake: whereas the evil, which is the object of sorrow, is to be shunned as being a privation of good: and that which is by reason of itself is stronger than that which is by reason of something else. Moreover we find a confirmation of this in natural movements. For every natural movement is more intense in the end, when a thing approaches the term that is suitable to its nature, than at the beginning, when it leaves the term that is unsuitable to its nature: as though nature were more eager in tending to what is suitable to it, than in shunning what is unsuitable. Therefore the inclination of the appetitive power is, of itself, more eager in tending to pleasure than in shunning sorrow.But it happens accidentally that a man shuns sorrow more eagerly than he seeks pleasure: and this for three reasons. First, on the part of the apprehension. Because, as Augustine says (De Trin. x, 12), "love is felt more keenly, when we lack that which we love." Now from the lack of what we love, sorrow results, which is caused either by the loss of some loved good, or by the presence of some contrary evil. But pleasure suffers no lack of the good loved, for it rests in possession of it. Since then love is the cause of pleasure and sorrow, the latter is more the shunned, according as love is the more keenly felt on account of that which is contrary to it. Secondly, on the part of the cause of sorrow or pain, which cause is repugnant to a good that is more loved than the good in which we take pleasure. For we love the natural well-being of the body more than the pleasure of eating: and consequently we would leave the pleasure of eating and the like, from fear of the pain occasioned by blows or other such causes, which are contrary to the well-being of the body. Thirdly, on the part of the effect: namely, in so far as sorrow hinders not only one pleasure, but all.
Reply to Objection: 1. The saying of Augustine that "sorrow is shunned more than pleasure is sought" is true accidentally but not simply. And this is clear from what he says after: "Since we see that the most savage animals are deterred from the greatest pleasures by fear of pain," which pain is contrary to life which is loved above all.
2. It is not the same with movement from within and movement from without. For movement from within tends to what is suitable more than it recedes from that which is unsuitable; as we remarked above in regard to natural movement. But movement from without is intensified by the very opposition: because each thing strives in its own way to resist anything contrary to it, as aiming at its own preservation. Hence violent movement is intense at first, and slackens towards the end. Now the movement of the appetitive faculty is from within: since it tends from the soul to the object. Consequently pleasure is, of itself, more to be sought than sorrow is to be shunned. But the movement of the sensitive faculty is from without, as it were from the object of the soul. Consequently the more contrary a thing is the more it is felt. And then too, accidentally, in so far as the senses are requisite for pleasure and pain, pain is shunned more than pleasure is sought.
3. A brave man is not praised because, in accordance with reason, he is not overcome by any kind of sorrow or pain whatever, but because he is not overcome by that which is concerned with the dangers of death. And this kind of sorrow is more shunned, than pleasures of the table or of sexual intercourse are sought, which latter pleasures are the object of temperance: thus life is loved more than food and sexual pleasure. But the temperate man is praised for refraining from pleasures of touch, more than for not shunning the pains which are contrary to them, as is stated in Ethic. iii, 11.
Objection: 1. It would seem that outward pain is greater than interior sorrow of the heart. Because outward pain arises from a cause repugnant to the well-being of the body in which is life: whereas interior sorrow is caused by some evil in the imagination. Since, therefore, life is loved more than an imagined good, it seems that, according to what has been said above (Article [6]), outward pain is greater than interior sorrow.
2. Further, the reality moves more than its likeness does. But outward pain arises from the real conjunction of some contrary; whereas inward sorrow arises from the apprehended likeness of a contrary. Therefore outward pain is greater than inward sorrow.
3. Further, a cause is known by its effect. But outward pain has more striking effects: since man dies sooner of outward pain than of interior sorrow. Therefore outward pain is greater and is shunned more than interior sorrow.
On the contrary it is written (Si 25,17): "The sadness of the heart is every wound [Douay: 'plague'], and the wickedness of a woman is all evil." Therefore, just as the wickedness of a woman surpasses all other wickedness, as the text implies; so sadness of the heart surpasses every outward wound.
I answer that Interior and exterior pain agree in one point and differ in two. They agree in this, that each is a movement of the appetitive power, as stated above (Article [1]). But they differ in respect of those two things which are requisite for pain and pleasure; namely, in respect of the cause, which is a conjoined good or evil; and in respect of the apprehension. For the cause of outward pain is a conjoined evil repugnant to the body; while the cause of inward pain is a conjoined evil repugnant to the appetite. Again, outward pain arises from an apprehension of sense, chiefly of touch; while inward pain arises from an interior apprehension, of the imagination or of the reason.If then we compare the cause of inward pain to the cause of outward pain, the former belongs, of itself, to the appetite to which both these pains belong: while the latter belongs to the appetite directly. Because inward pain arises from something being repugnant to the appetite itself, while outward pain arises from something being repugnant to the appetite, through being repugnant to the body. Now, that which is of itself is always prior to that which is by reason of another. Wherefore, from this point of view, inward pain surpasses outward pain. In like manner also on the part of apprehension: because the apprehension of reason and imagination is of a higher order than the apprehension of the sense of touch. Consequently inward pain is, simply and of itself, more keen than outward pain: a sign whereof is that one willingly undergoes outward pain in order to avoid inward pain: and in so far as outward pain is not repugnant to the interior appetite, it becomes in a manner pleasant and agreeable by way of inward joy. Sometimes, however, outward pain is accompanied by inward pain, and then the pain is increased. Because inward pain is not only greater than outward pain, it is also more universal: since whatever is repugnant to the body, can be repugnant to the interior appetite; and whatever is apprehended by sense may be apprehended by imagination and reason, but not conversely. Hence in the passage quoted above it is said expressively: "Sadness of the heart is every wound," because even the pains of outward wounds are comprised in the interior sorrows of the heart.
Reply to Objection: 1. Inward pain can also arise from things that are destructive of life. And then the comparison of inward to outward pain must not be taken in reference to the various evils that cause pain; but in regard to the various ways in which this cause of pain is compared to the appetite.
2. Inward pain is not caused by the apprehended likeness of a thing: for a man is not inwardly pained by the apprehended likeness itself, but by the thing which the likeness represents. And this thing is all the more perfectly apprehended by means of its likeness, as this likeness is more immaterial and abstract. Consequently inward pain is, of itself, greater, as being caused by a greater evil, forasmuch as evil is better known by an inward apprehension.
3. Bodily changes are more liable to be caused by outward pain, both from the fact that outward pain is caused by a corruptive conjoined corporally, which is a necessary condition of the sense of touch; and from the fact that the outward sense is more material than the inward sense, just as the sensitive appetite is more material than the intellective. For this reason, as stated above (Question [22], Article [3]; Question [31], Article [5]), the body undergoes a greater change from the movement of the sensitive appetite: and, in like manner, from outward than from inward pain.
Objection: 1. It would seem that Damascene's (De Fide Orth. ii, 14) division of sorrow into four species is incorrect; viz. into "torpor, distress," which Gregory of Nyssa [*Nemesius, De Nat. Hom. xix.] calls "anxiety,"---"pity," and "envy." For sorrow is contrary to pleasure. But there are not several species of pleasure. Therefore it is incorrect to assign different species of sorrow.
2. Further, "Repentance" is a species of sorrow; and so are "indignation" and "jealousy," as the Philosopher states (Rhet. ii, 9,11). But these are not included in the above species. Therefore this division is insufficient.
3. Further, the members of a division should be things that are opposed to one another. But these species are not opposed to one another. For according to Gregory [*Nemesius, De Nat. Hom. xix.] "torpor is sorrow depriving of speech; anxiety is the sorrow that weighs down; envy is sorrow for another's good; pity is sorrow for another's wrongs." But it is possible for one to sorrow for another's wrongs, and for another's good, and at the same time to be weighed down inwardly, and outwardly to be speechless. Therefore this division is correct.
On the contrary stands the twofold authority of Gregory of Nyssa [*Nemesius] and of Damascene.
I answer that It belongs to the notion of a species that it is something added to the genus. But a thing can be added to a genus in two ways. First, as something belonging of itself to the genus, and virtually contained therein: thus "rational" is added to "animal." Such an addition makes true species of a genus: as the Philosopher says (Metaph. vii, 12; viii, 2,3). But, secondly, a thing may be added to a genus, that is, as it were, foreign to the notion conveyed by that genus: thus "white" or something of the kind may be added to "animal." Such an addition does not make true species of the genus, according to the usual sense in which we speak of genera and species. But sometimes a thing is said to be a species of a certain genus, through having something foreign to that genus indeed, but to which the notion of that genus is applicable: thus a live coal or a flame is said to be a species of fire, because in each of them the nature of fire is applied to a foreign matter. In like manner we speak of astronomy and perspective as being species of mathematics, inasmuch as the principles of mathematics are applied to natural matter.In accordance with this manner of speaking, the species of sorrow are reckoned by an application of the notion of sorrow to something foreign to it. This foreign matter may be taken on the part of the cause or the object, or of the effect. For the proper object of sorrow is "one's own evil." Hence sorrow may be concerned for an object foreign to it either through one's being sorry for an evil that is not one's own; and thus we have "pity" which is sorrow for another's evil, considered, however, as one's own: or through one's being sorry for something that is neither evil nor one's own, but another's good, considered, however, as one's own evil: and thus we have "envy." The proper effect of sorrow consists in a certain "flight of the appetite." Wherefore the foreign element in the effect of sorrow, may be taken so as to affect the first part only, by excluding flight: and thus we have "anxiety" which weighs on the mind, so as to make escape seem impossible: hence it is also called "perplexity." If, however, the mind be weighed down so much, that even the limbs become motionless, which belongs to "torpor," then we have the foreign element affecting both, since there is neither flight, nor is the effect in the appetite. And the reason why torpor especially is said to deprive one of speech is because of all the external movements the voice is the best expression of the inward thought and desire, not only in men, but also in other animals, as is stated in Polit. i, 1.
Reply to Objection: 1. Pleasure is caused by good, which has only one meaning: and so pleasure is not divided into several species as sorrow is; for the latter is caused by evil, which "happens in many ways," as Dionysius says (Div. Nom. iv).
2. Repentance is for one's own evil, which is the proper object of sorrow: wherefore it does not belong to these species. Jealousy and indignation are included in envy, as we shall explain later (SS, Question [36], Article [2]).
3. This division is not according to opposite species; but according to the diversity of foreign matter to which the notion of sorrow is applied, as stated above.
We must now consider the causes of sorrow: under which head there are four points of inquiry:
(1) Whether sorrow is caused by the loss of a good or rather by the presence of an evil?
(2) Whether desire is a cause of sorrow?
(3) Whether the craving for unity is a cause of sorrow?
(4) Whether an irresistible power is a cause of sorrow?
Objection: 1. It would seem that sorrow is caused by the loss of a good rather than by the presence of an evil. For Augustine says (De viii Questions. Dulcit. qu. 1) that sorrow is caused by the loss of temporal goods. Therefore, in like manner, every sorrow is caused by the loss of some good.
2. Further, it was said above (Question [35], Article [4]) that the sorrow which is contrary to a pleasure, has the same object as that pleasure. But the object of pleasure is good, as stated above (Question [23], Article [4]; Question [31], Article [1]; Question [35], Article [3]). Therefore sorrow is caused chiefly by the loss of good.
3. Further, according to Augustine (De Civ. Dei xiv, 7,9), love is the cause of sorrow, as of the other emotions of the soul. But the object of love is good. Therefore pain or sorrow is felt for the loss of good rather than for an evil that is present.
On the contrary Damascene says (De Fide Orth. ii, 12) that "the dreaded evil gives rise to fear, the present evil is the cause of sorrow."
I answer that If privations, as considered by the mind, were what they are in reality, this question would seem to be of no importance. For, as stated in the FP, Question [14], Article [10] and FP, Question [48], Article [3], evil is the privation of good: and privation is in reality nothing else than the lack of the contrary habit; so that, in this respect, to sorrow for the loss of good, would be the same as to sorrow for the presence of evil. But sorrow is a movement of the appetite in consequence of an apprehension: and even a privation, as apprehended, has the aspect of a being, wherefore it is called "a being of reason." And in this way evil, being a privation, is regarded as a "contrary." Accordingly, so far as the movement of the appetite is concerned, it makes a difference which of the two it regards chiefly, the present evil or the good which is lost.Again, since the movement of the animal appetite holds the same place in the actions of the soul, as natural movement in natural things; the truth of the matter is to be found by considering natural movements. For if, in natural movements, we observe those of approach and withdrawal, approach is of itself directed to something suitable to nature; while withdrawal is of itself directed to something contrary to nature; thus a heavy body, of itself, withdraws from a higher place, and approaches naturally to a lower place. But if we consider the cause of both these movements, viz. gravity, then gravity itself inclines towards the lower place more than it withdraws from the higher place, since withdrawal from the latter is the reason for its downward tendency.Accordingly, since, in the movements of the appetite, sorrow is a kind of flight or withdrawal, while pleasure is a kind of pursuit or approach; just as pleasure regards first the good possessed, as its proper object, so sorrow regards the evil that is present. On the other hand love, which is the cause of pleasure and sorrow, regards good rather than evil: and therefore, forasmuch as the object is the cause of a passion, the present evil is more properly the cause of sorrow or pain, than the good which is lost.
Reply to Objection: 1. The loss itself of good is apprehended as an evil, just as the loss of evil is apprehended as a good: and in this sense Augustine says that pain results from the loss of temporal goods.
2. Pleasure and its contrary pain have the same object, but under contrary aspects: because if the presence of a particular thin be the object of pleasure, the absence of that same thing is the object of sorrow. Now one contrary includes the privation of the other, as stated in Metaph. x, 4: and consequently sorrow in respect of one contrary is, in a way, directed to the same thing under a contrary aspect.
3. When many movements arise from one cause, it does not follow that they all regard chiefly that which the cause regards chiefly, but only the first of them. And each of the others regards chiefly that which is suitable to it according to its own nature.
Objection: 1. It would seem that desire is not a cause of pain or sorrow. Because sorrow of itself regards evil, as stated above (Article [1]): whereas desire is a movement of the appetite towards good. Now movement towards one contrary is not a cause of movement towards the other contrary. Therefore desire is not a cause of pain.
2. Further, pain, according to Damascene (De Fide Orth. ii, 12), is caused by something present; whereas the object of desire is something future. Therefore desire is not a cause of pain.
3. Further, that which is pleasant in itself is not a cause of pain. But desire is pleasant in itself, as the Philosopher says (Rhet. i, 11). Therefore desire is not a cause of pain or sorrow.
On the contrary Augustine says (Enchiridion xxiv): "When ignorance of things necessary to be done, and desire of things hurtful, found their way in: error and pain stole an entrance in their company." But ignorance is the cause of error. Therefore desire is a cause of sorrow.
I answer that Sorrow is a movement of the animal appetite. Now, as stated above (Article [1]), the appetitive movement is likened to the natural appetite; a likeness, that may be assigned to a twofold cause; one, on the part of the end, the other, on the part of the principle of movement. Thus, on the part of the end, the cause of a heavy body's downward movement is the lower place; while the principle of that movement is a natural inclination resulting from gravity.Now the cause of the appetitive movement, on the part of the end, is the object of that movement. And thus, it has been said above (Article [1]) that the cause of pain or sorrow is a present evil. On the other hand, the cause, by way or principle, of that movement, is the inward inclination of the appetite; which inclination regards, first of all, the good, and in consequence, the rejection of a contrary evil. Hence the first principle of this appetitive movement is love, which is the first inclination of the appetite towards the possession of good: while the second principle is hatred, which is the first inclination of the appetite towards the avoidance of evil. But since concupiscence or desire is the first effect of love, which gives rise to the greatest pleasure, as stated above (Question [32], Article [6]); hence it is that Augustine often speaks of desire or concupiscence in the sense of love, as was also stated (Question [30], Article [2], ad 2): and in this sense he says that desire is the universal cause of sorrow. Sometimes, however, desire taken in its proper sense, is the cause of sorrow. Because whatever hinders a movement from reaching its end is contrary to that movement. Now that which is contrary to the movement of the appetite, is a cause of sorrow. Consequently, desire becomes a cause of sorrow, in so far as we sorrow for the delay of a desired good, or for its entire removal. But it cannot be a universal cause of sorrow: since we sorrow more for the loss of present good, in which we have already taken pleasure, than for the withdrawal of future good which we desire to have.
Reply to Objection: 1. The inclination of the appetite to the possession of good causes the inclination of the appetite to fly from evil, as stated above. And hence it is that the appetitive movements that regard good, are reckoned as causing the appetitive movements that regard evil.
2. That which is desired, though really future, is, nevertheless, in a way, present, inasmuch as it is hoped for. Or we may say that although the desired good itself is future, yet the hindrance is reckoned as present, and so gives rise to sorrow.
3. Desire gives pleasure, so long as there is hope of obtaining that which is desired. But, when hope is removed through the presence of an obstacle, desire causes sorrow.
Objection: 1. It would seem that the craving for unity is not a cause of sorrow. For the Philosopher says (Ethic. x, 3) that "this opinion," which held repletion to be the cause of pleasure, and division [*Aristotle wrote (endeian), 'want'; St. Thomas, in the Latin version, read 'incisionem'; should he have read 'indigentiam'?], the cause of sorrow, "seems to have originated in pains and pleasures connected with food." But not every pleasure or sorrow is of this kind. Therefore the craving for unity is not the universal cause of sorrow; since repletion pertains to unity, and division is the cause of multitude.
2. Further, every separation is opposed to unity. If therefore sorrow were caused by a craving for unity, no separation would be pleasant: and this is clearly untrue as regards the separation of whatever is superfluous.
3. Further, for the same reason we desire the conjunction of good and the removal of evil. But as conjunction regards unity, since it is a kind of union; so separation is contrary to unity. Therefore the craving for unity should not be reckoned, rather than the craving for separation, as causing sorrow.
On the contrary Augustine says (De Lib. Arb. iii, 23), that "from the pain that dumb animals feel, it is quite evident how their souls desire unity, in ruling and quickening their bodies. For what else is pain but a feeling of impatience of division or corruption?"
I answer that Forasmuch as the desire or craving for good is reckoned as a cause of sorrow, so must a craving for unity, and love, be accounted as causing sorrow. Because the good of each thing consists in a certain unity, inasmuch as each thing has, united in itself, the elements of which its perfection consists: wherefore the Platonists held that "one" is a principle, just as "good" is. Hence everything naturally desires unity, just as it desires goodness: and therefore, just as love or desire for good is a cause of sorrow, so also is the love or craving for unity.
Reply to Objection: 1. Not every kind of union causes perfect goodness, but only that on which the perfect being of a thing depends. Hence neither does the desire of any kind of unity cause pain or sorrow, as some have maintained: whose opinion is refuted by the Philosopher from the fact that repletion is not always pleasant; for instance, when a man has eaten to repletion, he takes no further pleasure in eating; because repletion or union of this kind, is repugnant rather than conducive to perfect being. Consequently sorrow is caused by the craving, not for any kind of unity, but for that unity in which the perfection of nature consists.
2. Separation can be pleasant, either because it removes something contrary to a thing's perfection, or because it has some union connected with it, such as union of the sense to its object.
3. Separation from things hurtful and corruptive is desired, in so far as they destroy the unity which is due. Wherefore the desire for such like separation is not the first cause of sorrow, whereas the craving for unity is.
Objection: 1. It would seem that a greater power should not be reckoned a cause of sorrow. For that which is in the power of the agent is not present but future. But sorrow is for present evil. Therefore a greater power is not a cause of sorrow.
2. Further, hurt inflicted is the cause of sorrow. But hurt can be inflicted even by a lesser power. Therefore a greater power should not be reckoned as a cause of sorrow.
3. Further, the interior inclinations of the soul are the causes of the movements of appetite. But a greater power is something external. Therefore it should not be reckoned as a cause of sorrow.
On the contrary Augustine says (De Nat. Boni xx): "Sorrow in the soul is caused by the will resisting a stronger power: while pain in the body is caused by sense resisting a stronger body."
I answer that As stated above (Article [1]), a present evil, is cause of sorrow or pain, by way of object. Therefore that which is the cause of the evil being present, should be reckoned as causing pain or sorrow. Now it is evident that it is contrary to the inclination of the appetite to be united with a present evil: and whatever is contrary to a thing's inclination does not happen to it save by the action of something stronger. Wherefore Augustine reckons a greater power as being the cause of sorrow.But it must be noted that if the stronger power goes so far as to transform the contrary inclination into its own inclination there will be no longer repugnance or violence: thus if a stronger agent, by its action on a heavy body, deprives it of its downward tendency, its consequent upward tendency is not violent but natural to it.Accordingly if some greater power prevail so far as to take away from the will or the sensitive appetite, their respective inclinations, pain or sorrow will not result therefrom; such is the result only when the contrary inclination of the appetite remains. And hence Augustine says (De Nat. Boni xx) that sorrow is caused by the will "resisting a stronger power": for were it not to resist, but to yield by consenting, the result would be not sorrow but pleasure.
Reply to Objection: 1. A greater power causes sorrow, as acting not potentially but actually, i.e. by causing the actual presence of the corruptive evil.
2. Nothing hinders a power which is not simply greater, from being greater in some respect: and accordingly it is able to inflict some harm. But if it be nowise stronger, it can do no harm at all: wherefore it cannot bring about that which causes sorrow.
3. External agents can be the causes of appetitive movements, in so far as they cause the presence of the object: and it is thus that a greater power is reckoned to be the cause of sorrow.
We must now consider the effects of pain or of sorrow: under which head there are four points of inquiry:
(1) Whether pain deprives one of the power to learn?
(2) Whether the effect of sorrow or pain is to burden the soul?
(3) Whether sorrow or pain weakens all activity?
(4) Whether sorrow is more harmful to the body than all the other passions of the soul?
Objection: 1. It would seem that pain does not deprive one of the power to learn. For it is written (Is 26,9): "When Thou shalt do Thy judgments on the earth, the inhabitants of the world shall learn justice": and further on (verse 16): "In the tribulation of murmuring Thy instruction was with them." But the judgments of God and tribulation cause sorrow in men's hearts. Therefore pain or sorrow, far from destroying, increases the power of learning.
2. Further, it is written (Is 28,9): "Whom shall He teach knowledge? And whom shall He make to understand the hearing? Them that are weaned from the milk, that are drawn away from the breasts," i.e. from pleasures. But pain and sorrow are most destructive of pleasure; since sorrow hinders all pleasure, as stated in Ethic. vii, 14: and (Si 11,29) it is stated that "the affliction of an hour maketh one forget great delights." Therefore pain, instead of taking away, increases the faculty of learning.
3. Further, inward sorrow surpasses outward pain, as stated above (Question [35], Article [7]). But man can learn while sorrowful. Much more, therefore, can he learn while in bodily pain.
On the contrary Augustine says (Soliloq. i, 12): "Although during those days I was tormented with a violent tooth-ache, I was not able to turn over in my mind other things than those I had already learnt; and as to learning anything, I was quite unequal to it, because it required undivided attention."
I answer that Since all the powers of the soul are rooted in the one essence of the soul, it must needs happen, when the intention of the soul is strongly drawn towards the action of one power, that it is withdrawn from the action of another power: because the soul, being one, can only have one intention. The result is that if one thing draws upon itself the entire intention of the soul, or a great portion thereof, anything else requiring considerable attention is incompatible therewith.Now it is evident that sensible pain above all draws the soul's attention to itself; because it is natural for each thing to tend wholly to repel whatever is contrary to it, as may be observed even in natural things. It is likewise evident that in order to learn anything new, we require study and effort with a strong intention, as is clearly stated in Pr 2,4-5: "If thou shalt seek wisdom as money, and shall dig for her as for a treasure, then shalt thou understand learning" [Vulg: 'the fear of the Lord']. Consequently if the pain be acute, man is prevented at the time from learning anything: indeed it can be so acute, that, as long as it lasts, a man is unable to give his attention even to that which he knew already. However a difference is to be observed according to the difference of love that a man has for learning or for considering: because the greater his love, the more will he retain the intention of his mind so as to prevent it from turning entirely to the pain.
Reply to Objection: 1. Moderate sorrow, that does not cause the mind to wander, can conduce to the acquisition of learning especially in regard to those things by which a man hopes to be freed from sorrow. And thus, "in the tribulation of murmuring," men are more apt to be taught by God.
2. Both pleasure and pain, in so far as they draw upon themselves the soul's intention, hinder the reason from the act of consideration, wherefore it is stated in Ethic. vii, 11 that "in the moment of sexual pleasure, a man cannot understand anything." Nevertheless pain attracts the soul's intention more than pleasure does: thus we observe in natural things that the action of a natural body is more intense in regard to its contrary; for instance, hot water is more accessible to the action of cold, and in consequence freezes harder. If therefore pain or sorrow be moderate, it can conduce accidentally to the facility of learning, in so far as it takes away an excess of pleasure. But, of itself, it is a hindrance; and if it be intense, it prevents it altogether.
3. External pain arises from hurt done to the body, so that it involves bodily transmutation more than inward sorrow does: and yet the latter is greater in regard to the formal element of pain, which belongs to the soul. Consequently bodily pain is a greater hindrance to contemplation which requires complete repose, than inward sorrow is. Nevertheless if inward sorrow be very intense, it attracts the intention, so that man is unable to learn anything for the first time: wherefore on account of sorrow Gregory interrupted his commentary on Ezechiel (Hom. xxii in Ezechiel).
Summa Th. I-II EN Qu.35 a.6