WHOEVER TRACES THE rather meagre history of dramatic criticism from Greek times to our own will observe that it has taken two principal forms -- the analytic and the impressionistic. The analyst's purpose has been to lay down rules and establish universal standards of judgment; the impressionist's, to set up no god but his own taste, and to write a history of the voyage of his soul among masterpieces. The value of his criticism has thus depended upon the value of his soul -- always an uncertain factor; and though writing of this school, when practised by men of quality, has yielded great treasures, the liberty, the artist's privilege necessary to impressionistic criticism has been shamefully abused, and is nowadays too often made an excuse for arrogant and disorderly variations on the pronoun "I". There is, in modern criticism, a real danger of anarchy if its erratic movements cannot by some means be related and stabilized. With every development of dramatic technique and every departure from classical structure, the need increases of a new discussion which, observing the changes of definition since Dryden and the vast accumulation of material since Lessing, shall establish for the stage not indeed a formal rule but an aesthetic discipline, elastic, reasoned, and acceptable to it in modern circumstances.