If he has never been on a quest for buried treasure, it can be demonstrated that he has never been a child

Robert Louis Stevenson’s single clearest literary essay, I’d say, is “A Humble Remonstrance” (1884).  Stevenson’s piece is a response to what is now considered a seminal Henry James essay, “The Art of Fiction” (1884).  The quality of his opponent presumably encouraged Stevenson to bring his best arguments. He only scores one point on James, but it’s a good one.

James first.  He is arguing that the novel is an expansive form, and favorably comparing Treasure Island to a psychological novel by Edmond de Goncourt:

I call Treasure Island delightful, because it appears to me to have succeeded wonderfully in what it attempts; and I venture to bestow no epithet upon Chérie, which strikes me as having failed in what it attempts - that is, in tracing the development of the moral consciousness of a child…  [But] the picture of the child's experience has the advantage that I can at successive steps (an immense luxury, near to the 'sensual pleasure' of which Mr. Besant's critic in the Pall Mall speaks) say Yes or No, as it may be, to what the artist puts before me.  I have been a child, but I have never been on a quest for a buried treasure, and it is a simple accident that with M. de Goncourt I should have for the most part to say No.

The temptation to edit Henry James was irresistible.  Stevenson, as one might guess, could not have been more pleased with James’s approval of his “little book about a quest for hidden treasure”, but that does not prevent him from flying straight to the weakness in James’s argument, “some rather startling words”:

In this book he misses what he calls the "immense luxury" of being able to quarrel with his author.  The luxury, to most of us, is to lay by our judgment, to be submerged by the tale as by a billow, and only to awake, and begin to distinguish and find fault, when the piece is over and the volume laid aside.  Still more remarkable is Mr. James's reason.  He cannot criticise the author, as he goes, "because," says he, comparing it with another work, "I have been a child, but I have never been on a quest for buried treasure."  Here is, indeed, a wilful paradox; for if he has never been on a quest for buried treasure, it can be demonstrated that he has never been a child.  There never was a child (unless Master James) but has hunted gold, and been a pirate, and a military commander, and a bandit of the mountains; but has fought, and suffered shipwreck and prison, and imbrued its little hands in gore, and gallantly retrieved the lost battle, and triumphantly protected innocence and beauty. (86)

Now, I can see a convincing objection to Stevenson: if there was ever a boy who did not behave as Stevenson suggests, that child could very well have been Henry James.  But that’s beside the point.

Stevenson’s literary essays form a concerted argument not to put away childish things.  They are a defense of a certain strain of the imagination, narrow but powerful.  “I believe, in a majority of cases, that the artist writes with more gusto and effect of those things which he has only wished to do, than of those which he has done” (86-7).  I suspect this is as true for James as for Stevenson, even if the things they wish to do vary considerably.  And I begin to see how this precise issue can divide readers of Stevenson, how a reader like Borges feels free to indulge this side of his imagination, while James, and perhaps Nabokov, join in more reluctantly, and another set of readers can dismiss Stevenson as willfully immature.  He is; they’re right. Stevenson’s literary essays are an argument for the high value of retaining some portion of our immaturity.

In real life, James and Stevenson became fairly close friends as a result of this exchange, a surprising happy ending to the story.