organs are receptive of another and natural change, which affects their natural disposition; for instance, when they become hot or cold, or undergo some similar change.  And whereas this kind of change is accidental to the act of the sensitive apprehension; for instance, if the eye be wearied through gazing intently at something or be overcome by the intensity of the object:  on the other hand, it is essential to the act of the sensitive appetite; wherefore the material element in the definitions of the movements of the appetitive part, is the natural change of the organ; for instance, “anger is” said to be “a kindling of the blood about the heart.”  Hence it is evident that the notion of passion is more consistent with the act of the sensitive appetite, than with that of the sensitive apprehension, although both are actions of a corporeal organ. ________________________

THIRD ARTICLE [I-II, Q. 22, Art. 3]

Whether Passion Is in the Sensitive Appetite Rather Than in the
Intellectual Appetite, Which Is Called the Will?

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.

Obj. 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.

Obj. 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 (A. 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.