Thomas Aquinas

“ When friendship is based on usefulness or pleasure, a man does indeed wish his friend some good: and in this respect the character of friendship is preserved. But since he refers this good further to his own pleasure or use, the result is that friendship of the useful or pleasant, in so far as it is connected with love of concupiscence, loses the character to true friendship. ”

“ 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. ”

“ Therefore love of concupiscence is distinct from love of friendship.
I answer that, As the Philosopher says (Rhet. ii, 4) , "to love is to wish good to someone." Hence the movement of love has a twofold tendency: towards the good which a man wishes to someone (to himself or to another) and towards that to which he wishes some good. Accordingly, man has love of concupiscence towards the good that he wishes to another, and love of friendship towards him to whom he wishes good. ”

“ 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." ”

“ 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 ”

“ Therefore concupiscence should not be contrasted with friendship.
On the contrary, We are said to love certain things, because we desire them: thus "a man is said to love wine, on account of its sweetness which he desires" ”

“ And it is in this sense that Augustine speaks of love in the passage quoted: hence a little further on he adds that "a right will is well-directed love, and a wrong will is ill-directed love." However, the fact that love, which is concupiscible passion, inclines many to evil, is the reason why some assigned the difference spoken of. ”

“ 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. ”

“ 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 ”