Whether sin has a cause?

❌ Objection 1 : It would seem that sin has no cause. For sin has the nature of evil, as stated above (Question [71], Article [6]). But evil has no cause, as Dionysius says (Div. Nom. iv). Therefore sin has no cause.

❌ Objection 2 : Further, a cause is that from which something follows of necessity. Now that which is of necessity, seems to be no sin, for every sin is voluntary. Therefore sin has no cause.

❌ Objection 3 : Further, if sin has a cause, this cause is either good or evil. It is not a good, because good produces nothing but good, for "a good tree cannot bring forth evil fruit" (Mt. 7:18). Likewise neither can evil be the cause of sin, because the evil of punishment is a sequel to sin, and the evil of guilt is the same as sin. Therefore sin has no cause.