MEGILLUS: What do you mean?
ATHENIAN: We are all aware that most men, in spite of their lawless natures, are very strictly and precisely restrained from intercourse with the fair, and this is not at all against their will, but entirely with their will.
MEGILLUS: When do you mean?
ATHENIAN: When any one has a brother or sister who is fair; and about a son or daughter the same unwritten law holds, and is a most perfect safeguard, so that no open or secret connexion ever takes place between them. Nor does the thought of such a thing ever enter at all into the minds of most of them.
MEGILLUS: Very true.
ATHENIAN: Does not a little word extinguish all pleasures of that sort?
MEGILLUS: What word?
ATHENIAN: The declaration that they are unholy, hated of God, and most infamous; and is not the reason of this that no one has ever said the opposite, but every one from his earliest childhood has heard men speaking in the same manner about them always and everywhere, whether in comedy or in the graver language of tragedy? When the poet introduces on the stage a Thyestes or an Oedipus, or a Macareus having secret intercourse with his sister, he represents him, when found out, ready to kill himself as the penalty of his sin.
MEGILLUS: You are very right in saying that tradition, if no breath of opposition ever assails it, has a marvellous power.
ATHENIAN: Am I not also right in saying that the legislator who wants to master any of the passions which master man may easily know how to subdue them? He will consecrate the tradition of their evil character among all, slaves and freemen, women and children, throughout the city: that will be the surest foundation of the law which he can make.