IT was Landor's opinion that "the best writers in every age have written in dialogue"; but it is curious how little, apart from the classifications of the Platonists, has been written about the dialogue. No attempt seems ever to have been made to define the principles of such a literary form; and while it is a method much used by a disciplined cast of mind, it has scarcely become one of classical precision. Perhaps if we were wise we should rejoice in one field left unmown by the blades of pedantry and logic; but categories are dear to the critic, and a short essay in eliminations may not be without interest to the general reader.
A cursory review of "the best writers" reveals a use of three distinct kinds of dialogue, agreeing only in the superficial appearance of the printed page. There is (i) the dialogue of ideas, in which the speakers are but embodiments of points of view; such a dialogue is exemplified in the characteristic work of Plato, Berkeley, Leopardi, Renan, and (to-day) M. Paul Valéry. To this category we might add, in so far as it ever becomes an artistic form, the dialogue of instruction, such