Whether disobedience is a mortal sin?

❌ Objection 1 : It seems that disobedience is not a mortal sin. For every sin is a disobedience, as appears from Ambrose's definition given above (Question [104], Article [2], Objection [1]). Therefore if disobedience were a mortal sin, every sin would be mortal.

❌ Objection 2 : Further, Gregory says (Moral. xxxi) that disobedience is born of vainglory. But vainglory is not a mortal sin. Neither therefore is disobedience.

❌ Objection 3 : Further, a person is said to be disobedient when he does not fulfil a superior's command. But superiors often issue so many commands that it is seldom, if ever, possible to fulfil them. Therefore if disobedience were a mortal sin, it would follow that man cannot avoid mortal sin, which is absurd. Wherefore disobedience is not a mortal sin.