Javier Marías is currently looked on as the finest Spanish novelist — meaning a novelist from Spain, not merely one who writes in Spanish. I’m not yet persuaded he’s better than Carlos Ruiz Zafón, but he’s pretty damn good.
Anyhow, to the topic. There’s an article by Marías, translated nicely into English, in Threepenny Review. Title: “Seven Reasons Not to Write Novels and Only One Reason to Write Them.” [http://www.threepennyreview.com/samples/marias_su14.html]