Reply Obj. 2: Passion causes sin as regards the adherence to something. But that this be a mortal sin regards the aversion, which follows accidentally from the adherence, as stated above (A. 6, ad 1): hence the argument does not prove.
Reply Obj. 3: Passion does not always hinder the act of reason altogether: consequently the reason remains in possession of its free-will, so as to turn away from God, or turn to Him. If, however, the use of reason be taken away altogether, the sin is no longer either mortal or venial. ________________________
QUESTION 78
OF THAT CAUSE OF SIN WHICH IS MALICE
(In Four Articles)
We must now consider the cause of sin on the part of the will, viz. malice: and under this head there are four points of inquiry:
(1) Whether it is possible for anyone to sin through certain malice, i.e. purposely?
(2) Whether everyone that sins through habit, sins through certain malice?
(3) Whether every one that sins through certain malice, sins through habit?
(4) Whether it is more grievous to sin through certain malice, than through passion? ________________________
FIRST ARTICLE [I-II, Q. 78, Art. 1]