Ratio passionis magis proprie invenitur in actu appetitus sensitivi quam intellectivi, quia in actu appetitus intellectivi non requiritur aliqua transmutatio corporalis (quia huiusmodi appetitus non est virtus alicuius organi).
The formal aspect of passion is found more properly in the act of the sensitive appetite than in that of the intellectual appetite, because there is no need for corporeal transmutation in the act of the intellectual appetite (because this appetite is not exercised by means of a corporeal organ).
Amor et gaudium et alia huiusmodi, cum attribuuntur Deo vel Angelis, aut hominibus secundum appetitum intellectivum, significant simplicem actum voluntatis cum similitudine effectus, absque passione.
When love and joy and the like are ascribed to God or the angels, or to man in respect of his intellectual appetite, they signify simple acts of the will having like effects, but without passion.
Unde dicit Augustinus, IX de Civ. Dei, "sancti Angeli et sine ira puniunt et sine miseriae compassione subveniunt. Et tamen, istarum nomina passionum, consuetudine locutionis humanae, etiam in eos usurpantur, propter quandam operum similitudinem, non propter affectionum infirmitatem."
Hence Augustine says (De Civ. Dei ix, 5): "The holy angels feel no anger while they punish . . . no fellow-feeling with misery while they relieve the unhappy; and yet ordinary human speech is wont to ascribe to them also these passions by name, because, although they have none of our weakness, their acts bear a certain resemblance to ours."
Passio proprie invenitur ubi est transmutatio corporalis. Quae quidem invenitur in actibus appetitus sensitivi, et non solum spiritualis (sicut est in apprehensione sensitiva) sed etiam naturalis.
Passion is properly to be found where there is corporeal transmutation. This corporeal transmutation is found in the act of the sensitive appetite, and is not only spiritual (as in the sensitive apprehension) but also natural.
Dicit Damascenus, in II libro, describens animales passiones, "Passio est motus appetitivae virtutis sensibilis in imaginatione boni vel mali. Et aliter, passio est motus irrationalis animae per suspicionem boni vel mali."
Damascene says (De Fide Orth. ii, 22), while describing the animal passions: "Passion is a movement of the sensitive appetite when we imagine good or evil. In other words, passion is a movement of the irrational soul, when we think of good or evil."