1.--Book I. Sermon 17, on Confession.

Repentance then becomes capable of wiping out every sin, when on the occurrence of the soul's fault it admits no delay, and does not let the impulse pass on to a long space of time. For it is in this way that evil will be unable to leave a trace in us, being plucked away at the moment of its assault like a newly planted plant.

As the creatures called crabs are easy to catch, from their going sometimes forward and sometimes backward; so also the soul, which at one time is laughing, at another weeping, and at another giving way to luxury, can do no good.

He who is sometimes grieving, and is sometimes enjoying himself and laughing, is like a man pelting the dog of voluptuousness with bread, who chases it in appearance, but in fact invites it to remain near him.