/summa/FS/FSV/FS_Q77:
We must now consider the cause of sin, on the part of the sensitive appetite, as to whether a passion of the soul may be a cause of sin: and under this head there are eight points of inquiry:
(1) Whether a passion of the sensitive appetite can move or incline the will?
(2) Whether it can overcome the reason against the latter's knowledge?
(3) Whether a sin resulting from a passion is a sin of weakness?
(4) Whether the passion of self-love is the cause of every sin?
(5) Of three causes mentioned in 1 Jn. 2:16: "Concupiscence of the eyes, Concupiscence of the flesh," and "Pride of life."
(6) Whether the passion which causes a sin diminishes it?
(7) Whether passion excuses from sin altogether?
(8) Whether a sin committed through passion can be mortal?