Human law cannot punish or forbid all evil, since while doing away with evils it would do away with many good things, which would hinder the advance of the common good.
Saint AugustineWhat then, is correctness of speech but the maintenance of the practice of others, as established by the authority of ancient speakers? But the weaker men are, the more they are troubled by such matters. Their weakness stems from a desire to appear learned, not with a knowledge of things, by which we are edified, but with a knowledge of signs, by which it is difficult not to be puffed up in some way; even a knowledge of things often makes people boastful, unless their necks are held down by the Lord's yoke.
Saint AugustineAlthough among heretics and schismatics there is the same Baptism, nevertheless, the remission of sins is not operative among them because of the very rottenness of discord and wickedness of dissension ... Baptism was in them, but it did not profit them outside the Church ... Outside the Church, Baptism works death because of discord.
Saint Augustine