Objection 1. It would seem that passion is not more in the sensitive than in the intellectual appetite. For Dionysius declares (Div. Nom. ii) Hierotheus "to be taught by a kind of yet more Godlike instruction; not only by learning Divine things, but also by suffering [patiens] them." But the sensitive appetite cannot "suffer" Divine things, since its object is the sensible good. Therefore passion is in the intellectual appetite, just as it is also in the sensitive appetite.
Objection 2. Further, the more powerful the active force, the more intense the passion. But the object of the intellectual appetite, which is the universal good, is a more powerful active force than the object of the sensitive appetite, which is a particular good. Therefore passion is more consistent with the intellectual than with the sensitive appetite.
Objection 3. Further, joy and love are said to be passions. But these are to be found in the intellectual and not only in the sensitive appetite: else they would not be ascribed by the Scriptures to God and the angels. Therefore the passions are not more in the sensitive than in the intellectual appetite.
On the contrary, 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."
I answer that, As stated above (Article 1) 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. Now 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. It is therefore evident that passion is more properly in the act of the sensitive appetite, than in that of the intellectual appetite; and this is again evident from the definitions of Damascene quoted above.
Reply to Objection 1. By "suffering" Divine things is meant being well affected towards them, and united to them by love: and this takes place without any alteration in the body.
Reply to Objection 2. Intensity of passion depends not only on the power of the agent, but also on the passibility of the patient: because things that are disposed to passion, suffer much even from petty agents. Therefore although the object of the intellectual appetite has greater activity than the object of the sensitive appetite, yet the sensitive appetite is more passive.
Reply to Objection 3. 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. 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."
Source: Summa Theologica (New Advent)