St. Clement of Alexandria calls impurity the metropolis of vices, by reason, doubtless, of the numberless other vices which are born of it and make their home around it. This leprosy of the soul, impurity, is worse than any leprosy of the body, inasmuch as the death of the soul is an infinitely greater evil than that of the body.
God has at times allowed some of his saints to experience something of the foulness which the sin of impurity inflicts on the soul of the one who commits it. So it was with St. Euthymius and St. Catherine of Siena, who discovered impure persons by the stench which emanated from their presence. { 387} It were well, perhaps, if all innocent persons possessed this rare gift of some of God's saints, for they might then easily avoid contracting from others the foul leprosy of impurity. No one, indeed, can look for a grace so extraordinary, but every one who has charge of others, especially of the young, should take every means suggested by wisdom and experience to preserve them from contact with persons already infected with this vile pestilence. A brief conversation with one badly tainted with the leprosy of impurity is oftentimes enough to implant its seeds in young and innocent hearts; and once the seeds are planted, they are hardly, if ever, entirely uprooted.
Leprosy not only attacked persons, but was found also in garments and in houses. So it is with the contagion of impurity, which not only watches its victim from the muddy eye of the libertine, but hides itself also in the folds of the lascivious dress, by which it is scattered abroad, and clings like some noxious vapor to the walls of houses where wanton deeds are done and loose language spoken. From all such persons, and things, and places keep the young and the innocent afar off. Let us remember that those only who love cleanness of heart shall have the King of heaven for their friend; and as we know from Holy Scripture that we cannot be chaste unless God gives us power to be so, let us ask him fervently and frequently for this most royal of all royal gifts, the gift of purity. Let us put aside all pride of heart, which, more than anything else, would provoke Almighty God to leave us to our own weakness and folly. Impurity is the lewd daughter of pride, while humility is the chaste mother of purity.