The term dialogue expresses basically reciprocal conversation between two or more persons. When reported or imitated in writing, "dialogue" labels a form of literature invented by the Greekss for purposes of rhetorical entertainment and instruction, and scarcely modified since the days of its invention.
A literary dialogue is in reality a little drama without a theatre, and with scarcely any change of scene. It should be illuminated with those qualities which La Fontaine applauded in the dialogue of Plato, namely vivacity, fidelity of tone, and accuracy in the opposition of opinions. It has always been a favourite with those writers who have something to censure or to impart, but who love to stand outside the pulpit, and to encourage others to pursue a train of thought which the author does not seem to do more than indicate. The dialogue is so spontaneous a mode of expressing and noting down the undulations of human thought that it almost escapes analysis. All that is recorded, in any literature, of what pretend to be the actual words spoken by living or imaginary people is of the nature of dialogue. One branch of letters, the drama, is entirely founded upon it. But in its technical sense the word is used to describe what the Greek philosophers invented, and what the noblest of them lifted to the extreme refinement of an art.
The systematic use of dialogue as an independent literary form is commonly supposed to have been introduced by Plato, whose earliest experiment in it is believed to survive in the Ladies. The Platonic dialogue, however, was founded on the mime, which had been cultivated half a century earlier by the Sicilian poets, Sophron and Epicharmus. The works of these writers, which Plato admired and imitated, are lost, but it is believed that they were little plays, usually with only two performers. The rediscovered mimes of Herodas (Herondas) give us some idea of their scope.
Plato further simplified the form, and reduced it to pure argumentative conversation, while leaving intact the amusing element of character-drawing. He must have begun this about the year 405 BC, and by 399 he had brought the dialogue to its highest perfection, especially in the cycle directly inspired by the death of Socrates. All his philosophical writings, except the Apology, are cast in this form. As the greatest of all masters of Greek prose style, Plato lifted his favourite instrument, the dialogue, to its highest splendour, and to this day he remains by far its most distinguished proficient.
In the 2nd century A.D. Lucian of Samosata achieved a brilliant success with his ironic dialogues Of the Gods, Of the Dead, Of Love and Of the Courtesans. In some of them he attacks superstition and philosophical error with the sharpness of his wit; in others he merely paints scenes of modern life.
The title of Lucian’s most famous collection was borrowed in the 17th century by two French writers of eminence, each of whom prepared Dialogues des morts. These were Fontenelle (1683) and Fénelon (1712). In. English non-dramatic literature the dialogue had not been extensively employed until Berkeley used it, in 1713, for his Platonic treatise, Hylas and Philonous. Landor’s Imaginary Conversations (1821 - 1828) formed the most famous English example of dialogue in the 19th century, although the dialogues of Sir Arthur Helps claim attention.
In Germany, Wieland adopted this form for several important satirical works published between 1780 and 1799. In Spanish literature, the Dialogues of Valdés (1528) and those on Painting (1633) by Vincenzo Carducci are celebrated. In Italian, collections of dialogues, on the model of Plato, have been composed by Torquato Tasso (1586), by Galileo (1632), by Galiani (1770), by Leopardi (1825), and by a host of lesser writers.
More recently, the French returned to the original application of dialogue, and the inventions of "Gyp", of Henri Lavedan and of others, in which a mundane anecdote is wittily and maliciously told in conversation, would probably present a close analogy to the lost mimes of the early Sicilian poets, if we could meet with them.
This kind of dialogue has been employed in English, and with conspicuous cleverness by Mr Anstey Guthrie, but it does not seem so easily appreciated by English as by French readers.
Original text from http://1911encyclopedia.org