Avoid idleness, dissipated companions, immodest conversations, and, more than all, evil occasions, especially where there is danger of incontinency; and for this reason one cannot be too cautious in keeping one's eyes from dwelling on any dangerous objects. For a person that does not avoid the voluntary occasions of sin, especially those which have frequently proved fatal to his innocence, it is morally impossible to persevere in the grace of God: He that loves the danger shall perish in it.
--St. Alphonsus Liguori, The Way of Salvation and Perfection
