The most common mistake I see in book discussions — in person, online, in formal reviews — is treating the author's biography as the primary text. The book is the primary text. The author's life is context, sometimes useful context, but it's not the argument. The argument is in the book.

This doesn't mean biography is irrelevant. Understanding that Woolf was writing To the Lighthouse while her own father was on her mind changes how I read it. Knowing that Fitzgerald was writing Tender is the Night while his wife was in psychiatric care changes what I see in it. These are genuinely illuminating contexts.

What I resist is the move from biography to interpretive authority — the claim that what a book means is determined by what its author intended. The text is the evidence. Intentions are one kind of evidence. The text usually contains more.