You once asked me why I did not write a Don Juan play. The levity with which you assumed this frightful responsibility has probably by this time enabled you to forget it; but the day of reckoning has arrived: here is your play! I say your play, because qui facit per alium facit per se. Its profits, like its labor, belong to me: its morals, its manners, its philosophy, its influence on the young, are for you to justify.