ignorance in
the reason sometimes follows the inclination of the appetite, and
then such like ignorance, the greater it is, the graver the sin,
because the inclination of the appetite is shown thereby to be
greater. Now in both the incontinent and the intemperate man,
ignorance arises from the appetite being inclined to something,
either by passion, as in the incontinent, or by habit, as in the
intemperate. Nevertheless greater ignorance results thus in the
intemperate than in the incontinent. In one respect as regards
duration, since in the incontinent man this ignorance lasts only
while the passion endures, just as an attack of intermittent fever
lasts as long as the humor is disturbed: whereas the ignorance of the
intemperate man endures without ceasing, on account of the endurance
of the habit, wherefore it is likened to phthisis or any chronic
disease, as the Philosopher says (Ethic. vii, 8). In another respect
the ignorance of the intemperate man is greater as regards the thing
ignored. For the ignorance of the incontinent man regards some
particular detail of choice (in so far as he deems that he must
choose this particular thing now): whereas the intemperate man's
ignorance is about the end itself, inasmuch as he judges this thing
good, in order that he may follow his desires without being curbed.
Hence the Philosopher says (Ethic. vii, 7, 8) that "the incontinent
man is better than the intemperate, because he retains the best
principle [*_To beltiston, e arche_, 'the best thing, i.e. the
principle']," to wit, the right estimate of the end.

Reply Obj. 2: Mere knowledge does not suffice to cure the incontinent
man, for he needs the inward assistance of grace which quenches
concupiscence, besides the application of the external remedy of
admonishment and correction, which induce him to begin to resist his
desires, so that concupiscence is weakened, as stated above (Q. 142,
A. 2). By these same means the intemperate man can be cured. But his
curing is more difficult, for two reasons. The first is on the part
of reason, which is corrupt as regards the estimate of the last end,
which holds the same position as the principle in demonstrations. Now
it is more difficult to bring back to the truth one who errs as to
the principle; and it is the same in practical matters with one who
errs in regard to the end. The other reason is on the part of the
inclination of the appetite: for in the intemperate man this proceeds
f