Ignorance as a Cause of Sin

The active cause of sin is the will under the light and judgment of intellect; that is, the cause of sin is the reason. Now, ignorance may deprive reason of guiding knowledge that it ought to have, and therefore may bear upon the committing of sin. Thus, in some sense, ignorance may be the cause of sin.

Ignorance is itself a sin when it is a man’s own fault and pertains to things that he is under obligation toknow.

Ignorance which is not one’s own fault, and whichdeprives one of knowledge which would have prevented a sinful act,excuses from the guilt of sin.

Ignorance that is not directly willed tends to diminish the guilt of sin that comes as a result of it.