The conditions for mortal sin—grave matter, sufficient reflection, and full consent—were stated in chapter fifteen. Then, in chapter sixteen, the problem of grave and light matter was considered at length. The present chapter will clarify what is meant by sufficient reflection and then examine sins of weakness. Weakness somehow limits responsibility. The question is whether, even in the presence of sufficient reflection and the definite, free choice which constitutes full consent, it can make venial what would otherwise be a mortal sin. It need hardly be said that the questions treated in this chapter are important for the pastoral work of a priest.
The awareness required for sufficient reflection is at the level of moral truth concerning the gravity of the act. This awareness need not include an insight into why the act would be wrong. Emotion can mitigate guilt. However, sins of weakness which meet the usual conditions for mortal sin must be presumed to be mortal sins. With God’s grace, every sinner can stop sinning. The sinner through weakness is no exception.