Clement of Alexandria

From filthy speaking we ourselves must entirely abstain, and stop the mouths of those who practise it by stern looks and averting the face, and by what we call making a mock of one: often also by a harsher mode of speech. "For what proceedeth out of the mouth," He says, "defileth a man,"—shows him to be unclean, and heathenish, and untrained, and licentious, and not select, and proper, and honourable, and temperate. And as a similar rule holds with regard to hearing and seeing in the case of what is obscene, the divine Instructor, following the same course with both, arrays those children who are engaged in the struggle in words of modesty, as ear-guards, so that the pulsation of fornication may not penetrate to the bruising of the soul; and He directs the eyes to the sight of what is honourable, saying that it is better to make a slip with the feet than with the eyes. This filthy speaking the apostle beats off, saying, "Let no corrupt communication proceed out of your mouth, but what is good." And again, "As becometh saints, let not filthiness be named among you, nor foolish talking, nor jesting, which things are not seemly, but rather giving of thanks."