“A Chapter on Dreams” by Robert Louis Stevenson: He gives most of the credit for his published fiction to his alternate personalities, his “unseen collaborators”

“…But presently my dreamer…began to write and sell his tales. Here was he, and here were the little people who did that part of his business…

“…how often have these sleepless Brownies done him honest service, and given him, as he sat idly taking his pleasure in the boxes, better tales than he could fashion for himself. Here is one, exactly as it came to him…

[the story is outlined]

“For now [the reader] sees why I speak of the little people as substantive inventors and performers. To the end they had kept their secret. I will go bail for the dreamer…that he had no guess whatsoever at the motive of the woman—the hinge of the whole well-invented plot—until the instant of that highly dramatic declaration. It was not his tale; it was the little people’s!…

“But observe: not only was the secret kept, the story was told with really guileful craftsmanship. The conduct of both actors is…psychologically correct, and the emotion aptly graduated up to the surprising climax. I am awake now, and I know this trade; and yet I cannot better it…

“Who are the Little People? They are near connections of the dreamer’s, beyond doubt…only I think they have more talent; and one thing is beyond doubt, they can tell him a story piece by piece, like a serial, and keep him all the while in ignorance of where they aim. Who are they, then? and who is the dreamer?

“Well, as regards the dreamer, I can answer that, for he is no less a person than myself…And for the Little People, what shall I say they are but just my Brownies, God bless them!…That part which is done while I am sleeping is the Brownies’ part beyond contention; but that which is done when I am up and about is by no means necessarily mine, since all goes to show the Brownies have a hand in it even then. For myself—what I call I, my conscious ego…I am sometimes tempted to suppose he is no story-teller at all…so that, by that account, the whole of my published fiction should be the single-handed product of some Brownies, some Familiar, some unseen collaborator, whom I keep locked in a back garret, while I get all the praise…I am an excellent adviser…I pull back and I cut down; and I dress the whole in the best words and sentences that I can find and make; I hold the pen, too; and I do the sitting at the table, which is about the worst of it; and when all is done, I make up the manuscript and pay for the registration; so that, on the whole I have some claim to share, though not as largely as I do, in the profits of our common enterprise…”

Robert Louis Stevenson. “A Chapter on Dreams,” Scribner’s Magazine, January 1888, pp. 122-128.