"Would you write on a desert island?"

There has been a nagging recollection, about writing on a desert island with nobody to write to, that has till now eluded me. I knew that I would find some passage of that sort in a book I had read, but I couldn't put my finger down on which book. I did a quick Google search but found nothing. Pulling out David Foster Wallace didn't help; the essays he wrote were sublime but for the most part irrelevant.

Just this morning I finally remembered: Jean-Paul Sartre's Nausea.

This excerpt contains a dialogue between the protagonist and narrator, Roquentin, and a "Self-Taught Man", whom I would not characterize as Roquentin's friend, no matter how much the Self-Taught Man might think himself to be so. The subject is brought up on account of Roquentin's writing on a historical figure. The excerpt begins with the Self-Taught Man — who has a penchant for piercing queries (although perhaps with the Self-Taught Man oblivious of his own irritating aquiline insight), astute and incisive enough to draw many a candid "ouch" or an "oof" from me — asking whether Roquentin shares his own sentiments about Socialism:

"Don't you feel as I do, Monsieur?"

"Gracious...."

Under his troubled, somewhat spiteful glance, I regret disappointing him for a second. But he continues amiably:

"I know: you have your research, your books, you serve the same cause [humanistic Socialism] in your own way."

My books, my research: the imbecile. He couldn't have made a worse howler.

"That's not why I'm writing."

At that instant the face of the Self-Taught Man is transformed: as if he had scented the enemy. I had never seen that expression on his face before. Something has died between us.

Feigning surprise, he asks:

"But ... if I'm not being indiscreet, why do you write, Monsieur?"

"I don't know: just to write."

He smiles, he thinks he has put me out:

"Would you write on a desert island? Doesn't one always write to be read?"

He gave this sentence his usual interrogative turn. In reality, he is affirming. His veneer of gentleness and timidity has peeled off; I don't recognize him any more. His features assume an air of heavy obstinacy; a wall of sufficiency. I still haven't got over my astonishment when I hear him say:

"If someone tells me: I write for a certain social class, for a group of friends. Good luck to them. Perhaps you write for posterity.... But, Monsieur, in spite of yourself, you write for someone."

 He waits for an answer. When it doesn't come, he smiles feebly.

"Perhaps you are a misanthrope?" 

Roquentin gives up the discussion after two paragraphs of internal monologue: "I am not a humanist, that's all there is to it."

This passage, or the memory of it, has been hounding me for about a month now, because I've often wondered whether I myself write for an audience, to try to better other people in any way, or merely for myself — and David Foster Wallace has some well-informed things to say on the subject, delivering with singular robustness and oomph.

However, having reread the passages that follow the excerpt above, I found that that question only uncovers a more pressing issue in Roquentin's life; and that issue is personally convicting, as Sartre deals with it using the naive Self-Taught Man's characteristically dazing verbal blows and the vulnerated Roquentin's insipid responses and acrimonious, exasperated thoughts. I am not prepared to cover it in writing yet.