Eo modo quo concupiscentia vel cupiditas boni est causa doloris, etiam appetitus unitatis, vel amor, causa doloris ponendus est quia bonum uniuscuiusque rei in quadam unitate consistit, prout scilicet unaquaeque res habet in se unita illa ex quibus consistit eius perfectio.
Inasmuch as the desire or craving for good is reckoned as a cause of pain, so must a craving for unity, and love, be accounted as causing pain, 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.
Unde et Platonici posuerunt unum esse principium, sicut et bonum. Unde naturaliter unumquodque appetit unitatem, sicut et bonitatem. Et propter hoc, sicut amor vel appetitus boni est causa doloris, ita etiam amor vel appetitus unitatis.
Wherefore the Platonists held that "one" is a principle, just as "good" is. Hence everything naturally craves unity, just as it desires goodness. And therefore, just as love or craving for good is a cause of pain, so also is the love or craving for unity.
Non omnis unio perficit rationem boni, sed solum illa a qua dependet esse perfectum rei. Et propter hoc etiam, non cuiuslibet appetitus unitatis est causa doloris vel tristitiae, ut quidam opinabantur. Quorum opinionem ibi philosophus excludit per hoc, quod quaedam repletiones non sunt delectabiles: sicut repleti cibis non delectantur in ciborum sumptione. Talis enim repletio, sive unio, magis repugnaret ad perfectum esse, quam ipsum constitueret.
Not every kind of union perfects the formal aspect of the good, but only that on which the perfect being of a thing depends. Hence neither does the craving of any kind of unity cause pain or sadness, 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.
Unde dolor non causatur ex appetitu cuiuslibet unitatis, sed eius in qua consistit perfectio naturae.
Consequently pain is caused by the craving, not for any kind of unity, but for that unity in which the perfection of nature consists.
Separatio nocivorum et corrumpentium appetitur, inquantum tollunt debitam unitatem. Unde appetitus huiusmodi separationis non est prima causa doloris, sed magis appetitus unitatis.
Separation from things hurtful and corruptive is craved, insofar as they destroy the unity which is due. Wherefore the craving for this sort of separation is not the first cause of pain, whereas the craving for unity is.
Augustinus dicit, in III de libero arbitrio, "quod ex dolore quem bestiae sentiunt, satis apparet in regendis animandisque suis corporibus, quam sint animae appetentes unitatis. Quid enim est aliud dolor, nisi quidam sensus divisionis vel corruptionis impatiens?"
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 certain feeling of not wanting to suffer division or corruption?"