Amor est prima passionum concupiscibilis quia omne quod tendit ad finem aliquem, primo quidem habet aptitudinem seu proportionem ad finem, nihil enim tendit in finem non proportionatum; secundo, movetur ad finem; tertio, quiescit in fine post eius consecutionem. Ipsa autem aptitudo sive proportio appetitus ad bonum est amor, qui nihil aliud est quam complacentia boni; motus autem ad bonum est desiderium vel concupiscentia; quies autem in bono est gaudium vel delectatio.
Love is the first of the concupiscible passions because whatever tends to an end, has, in the first place, an aptitude or proportion to that end, for nothing tends to a disproportionate end; secondly, it is moved to that end; thirdly, it rests in the end, after having attained it. And this very aptitude or proportion of the appetite to good is love, which is complacency in good; while movement towards good is desire or concupiscence; and rest in good is joy or pleasure.
Et ideo secundum hunc ordinem, amor praecedit desiderium, et desiderium praecedit delectationem. Sed secundum ordinem intentionis, est e converso, nam delectatio intenta causat desiderium et amorem. Delectatio enim est fruitio boni, quae quodammodo est finis sicut et ipsum bonum, ut supra dictum est.
Accordingly in this order, love precedes desire, and desire precedes pleasure. But in the order of intention, it is the reverse, because the pleasure intended causes desire and love. For pleasure is the enjoyment of the good, which enjoyment is, in a way, the end, just as the good itself is, as stated above (q11, a3, ad 3).
Hoc modo nominatur aliquid, secundum quod nobis innotescit, voces enim sunt signa intellectuum, secundum philosophum. Nos autem, ut plurimum, per effectum cognoscimus causam. Effectus autem amoris, quando quidem habetur ipsum amatum, est delectatio; quando vero non habetur, est desiderium vel concupiscentia. Ut autem Augustinus dicit, in X de Trin., amor magis sentitur, cum eum prodit indigentia. Unde inter omnes passiones concupiscibilis, magis sensibilis est concupiscentia. Et propter hoc, ab ea denominatur potentia.
We name a thing as we understand it, for "words are signs of thoughts," as the Philosopher states (Peri Herm. i, 1). Now, in most cases, we know a cause by its effect. But the effect of love, when the beloved object is possessed, is pleasure; when it is not possessed, it is desire or concupiscence. And, as Augustine says (De Trin. x, 12), "we are more sensible to love, when we lack that which we love." Consequently of all the concupiscible passions, concupiscence is felt most. And for this reason the power is named after it.
Obiectum concupiscibilis sunt bonum et malum. Naturaliter autem est prius bonum malo, eo quod malum est privatio boni. Unde et omnes passiones, quarum obiectum est bonum, naturaliter sunt priores passionibus quarum obiectum est malum, unaquaeque scilicet sua opposita: quia enim bonum quaeritur, ideo refutatur oppositum malum.
Good and evil are the object of the concupiscible faculty. Now good naturally precedes evil, since evil is privation of good. Wherefore all the passions, the object of which is good, are naturally before those, the object of which is evil--that is to say, each precedes its contrary passion: for because a good is sought, therefore an opposite evil is shunned.
Bonum autem habet rationem finis, qui quidem est prior in intentione, sed est posterior in consecutione. Potest ergo ordo passionum concupiscibilis attendi vel secundum intentionem, vel secundum consecutionem. Secundum quidem consecutionem, illud est prius quod primo fit in eo quod tendit ad finem.
Now good has the formal aspect of an end, and the end is indeed first in the order of intention, but last in the order of execution. Consequently the order of the concupiscible passions can be considered either in the order of intention or in the order of execution. In the order of execution, the first place belongs to that which takes place first in the thing that tends to the end.
Augustinus dicit, in XIV de Civ. Dei, quod omnes passiones ex amore causantur, "amor enim inhians habere quod amatur, cupiditas est; id autem habens, eoque fruens, laetitia est".
Augustine says (De Civ. Dei xiv, 7,9) that all the passions are caused by love: since "love yearning for the beloved object, is desire; and, having and enjoying it, is joy."