Thomas Aquinas,
Summa Theologiae — Question 46 - THE PASSION OF CHRIST…
“ But the parts of a soul are its faculties. So, then, the whole soul is said to suffer in so far as it is afflicted as to its essence, or as to all its faculties. But it must be borne in mind that a faculty of the soul can suffer in two ways: first of all, by its own passion; and this comes of its being afflicted by its proper object; thus, sight may suffer from superabundance of the visible object. In another way a faculty suffers by a passion in the subject on which it is based ”
