“People think because a novel's invented, it isn't true. Exactly the reverse is the case. Because a novel's invented, it is true. Biography and memoirs can never be wholly true, since they can't include every conceivable circumstance of what happened. The novel can do that. The novelist himself lays it down. His decision is binding.”

from the preface to Indro Montanelli e Marco Nozza, Garibaldi, BUR.
2000s - 2010s

Source: Clockwork Princess

Recollections of Alexis de Tocqueville, p. 71 http://books.google.com/books?id=3gtoAAAAMAAJ&pg=PA71&dq=%22most+difficult+part+to+invent+is+the+end%22.
1850s and later

Hey, some people on tumblr are wondering if writers feel upset or get a thrill when they kill their characters. Care to enlighten us?, John Green's tumblr, Tumblr, January 1, 2013, July 15, 2014 http://fishingboatproceeds.tumblr.com/post/39363824562/hey-some-people-on-tumblr-are-wondering-if-writers,

Variant: Life is like a novel. It's filled with suspense. You have no idea what is going to happen until you turn the page.

Source: The Paris Review interview (1981), p. 338

"Introduction" to the French edition (1974) of Crash (1973); reprinted in Re/Search no. 8/9 (1984)
Crash (1973)
Context: We live in a world ruled by fictions of every kind — mass merchandising, advertising, politics conducted as a branch of advertising, the instant translation of science and technology into popular imagery, the increasing blurring and intermingling of identities within the realm of consumer goods, the preempting of any free or original imaginative response to experience by the television screen. We live inside an enormous novel. For the writer in particular it is less and less necessary for him to invent the fictional content of his novel. The fiction is already there. The writer's task is to invent the reality.

Source: The Age of Innocence