7 When the mind has thus been poisoned, at the same time the moral character becomes deeply and essentially corrupted; and such a state can only be cured with the utmost difficulty in this class of men, because on the one hand wrong opinions vitiate their judgment of what is right, and on the other the light of Christian faith, which is the principle and basis of all justice, is extinguished.
Source: Exeunte Iam Anno (Vatican.va)