Life imposes by brute energy, like inarticulate thunder; art catches the ear, among the far louder noises of experience, like an air artificially made by a discreet musician. A proposition of geometry does not compete with life; and a proposition of geometry is a fair and luminous parallel for a work of art. Both are reasonable, both untrue to the crude fact; both inhere in nature, neither represents it. The novel, which is a work of art, exists, not by its resemblances to life, which are forced and material, as a shoe must still consist of leather, but by its immeasurable difference from life, a difference which is designed and significant, and is both the method and the meaning of the work. The life of man is not the subject of novels, but the inexhaustible magazine from which subjects are to be selected; the name of these is legion; and with each new subject--for here again I must differ by the whole width of heaven from Mr. James--the true artist will vary his method and change the point of attack. That which was in one case an excellence, will become a defect in another; what was the making of one book, will in the next be impertinent or dull. First each novel, and then each class of novels, exists by and for itself. I will take, for instance, three main classes, which are fairly distinct: first, the novel of adventure, which appeals to certain almost sensual and quite illogical tendencies in man; second, the novel of character, which appeals to our intellectual appreciation of man's foibles and mingled and inconstant motives; and third, the dramatic novel, which deals with the same stuff as the serious theatre, and appeals to our emotional nature and moral judgment.