Whether love is in the concupiscible power?
Objection 1: It would seem that love is not in the concupiscible power. For it is written (Wis. 8:2): "Her," namely wisdom, "have I loved, and have sought her out from my youth." But the concupiscible power, being a part of the sensitive appetite, cannot tend to wisdom, which is not apprehended by the senses. Therefore love is not in the concupiscible power.
Objection 2: Further, love seems to be identified with every passion: for Augustine says (De Civ. Dei xiv, 7): "Love, yearning for the object beloved, is desire; having and enjoying it, is joy; fleeing what is contrary to it, is fear; and feeling what is contrary to it, is sadness." But not every passion is in the concupiscible power; indeed, fear, which is mentioned in this passage, is in the irascible power. Therefore we must not say absolutely that love is in the concupiscible power.
Objection 3: Further, Dionysius (Div. Nom. iv) mentions a "natural love." But natural love seems to pertain rather to the natural powers, which belong to the vegetal soul. Therefore love is not simply in the concupiscible power.
On the contrary, The Philosopher says (Topic. ii, 7) that "love is in the concupiscible power."
I answer that, Love is something pertaining to the appetite; since good is the object of both. Wherefore love differs according to the difference of appetites. For there is an appetite which arises from an apprehension existing, not in the subject of the appetite, but in some other: and this is called the "natural appetite." Because natural things seek what is suitable to them according to their nature, by reason of an apprehension which is not in them, but in the Author of their nature, as stated in the FP, Q 6, A 1, ad 2; FP, Q 103, A 1, ad 1,3. And there is another appetite arising from an apprehension in the subject of the appetite, but from necessity and not from free-will. Such is, in irrational animals, the "sensitive appetite," which, however, in man, has a certain share of liberty, in so far as it obeys reason. Again, there is another appetite following freely from an apprehension in the subject of the appetite. And this is the rational or intellectual appetite, which is called the "will."
Now in each of these appetites, the name "love" is given to the principle movement towards the end loved. In the natural appetite the principle of this movement is the appetitive subject's connaturalness with the thing to which it tends, and may be called "natural love": thus the connaturalness of a heavy body for the centre, is by reason of its weight and may be called "natural love." In like manner the aptitude of the sensitive appetite or of the will to some good, that is to say, its very complacency in good is called "sensitive love," or "intellectual" or "rational love." So that sensitive love is in the sensitive appetite, just as intellectual love is in the intellectual appetite. And it belongs to the concupiscible power, because it regards good absolutely, and not under the aspect of difficulty, which is the object of the irascible faculty.
Reply to Objection 1: The words quoted refer to intellectual or rational love.
Reply to Objection 2: Love is spoken of as being fear, joy, desire and sadness, not essentially but causally.
Reply to Objection 3: Natural love is not only in the powers of the vegetal soul, but in all the soul's powers, and also in all the parts of the body, and universally in all things: because, as Dionysius says (Div. Nom. iv), "Beauty and goodness are beloved by all things"; since each single thing has a connaturalness with that which is naturally suitable to it.
I–II · Q. 26, Art. 2: Whether love is a passion?
Whether love is a passion?
Objection 1: It would seem that love is not a passion. For no power is a passion. But every love is a power, as Dionysius says (Div. Nom. iv). Therefore love is not a passion.
Objection 2: Further, love is a kind of union or bond, as Augustine says (De Trin. viii, 10). But a union or bond is not a passion, but rather a relation. Therefore love is not a passion.
Objection 3: Further, Damascene says (De Fide Orth. ii, 22) that passion is a movement. But love does not imply the movement of the appetite; for this is desire, of which movement love is the principle. Therefore love is not a passion.
On the contrary, The Philosopher says (Ethic. viii, 5) that "love is a passion."
I answer that, Passion is the effect of the agent on the patient. Now a natural agent produces a twofold effect on the patient: for in the first place it gives it the form; and secondly it gives it the movement that results from the form. Thus the generator gives the generated body both weight and the movement resulting from weight: so that weight, from being the principle of movement to the place, which is connatural to that body by reason of its weight, can, in a way, be called "natural love." In the same way the appetible object gives the appetite, first, a certain adaptation to itself, which consists in complacency in that object; and from this follows movement towards the appetible object. For "the appetitive movement is circular," as stated in De Anima iii, 10; because the appetible object moves the appetite, introducing itself, as it were, into its intention; while the appetite moves towards the realization of the appetible object, so that the movement ends where it began. Accordingly, the first change wrought in the appetite by the appetible object is called "love," and is nothing else than complacency in that object; and from this complacency results a movement towards that same object, and this movement is "desire"; and lastly, there is rest which is "joy." Since, therefore, love consists in a change wrought in the appetite by the appetible object, it is evident that love is a passion: properly so called, according as it is in the concupiscible faculty; in a wider and extended sense, according as it is in the will.
Reply to Objection 1: Since power denotes a principle of movement or action, Dionysius calls love a power, in so far as it is a principle of movement in the appetite.
Reply to Objection 2: Union belongs to love in so far as by reason of the complacency of the appetite, the lover stands in relation to that which he loves, as though it were himself or part of himself. Hence it is clear that love is not the very relation of union, but that union is a result of love. Hence, too, Dionysius says that "love is a unitive force" (Div. Nom. iv), and the Philosopher says (Polit. ii, 1) that union is the work of love.
Reply to Objection 3: Although love does not denote the movement of the appetite in tending towards the appetible object, yet it denotes that movement whereby the appetite is changed by the appetible object, so as to have complacency therein.