How we cite our quotes: (Part.Chapter.Paragraph) or (Part.Paragraph)
Quote #1
She was one of those children possessed by a desire to have the world just so. (1.1.4)
Briony wants to have the world just so… and the version of reality she gives us in the novel is just so in many ways. The book is very carefully structured in its own right, and we eventually learn that she's cleaned up the ending too. Even if she hadn't though, fiction is almost always neater than fact.
Quote #2
Now there was nothing left of the dumb show by the fountain beyond what survived in memory, in three separate and overlapping memories. The truth had become as ghostly as invention. (1.3.16)
Briony is remembering the scene at the fountain, and also imagining Robbie and Cecilia remembering the scene at the fountain. She realizes that everybody has their own story going on in their own head, which means that everybody has their own version of reality. There's no one truth, so fact is just as much of a ghost as fiction. Briony finds this liberating and exciting. Having fiction treated as fact doesn't go so well for Robbie, though.
Quote #3
"It wasn't only wickedness and scheming that made people unhappy, it was confusion and misunderstanding; above all, it was the failure to grasp the simple truth that other people are as real as you. And only in a story could you enter these different minds and show how they had an equal value." (1.3.24)
This quote connects a number of themes—versions of reality, compassion, and writing. Writing is the way you acknowledge others's versions of reality and, in doing so, treat them with compassion. Briony's false accusation of Robbie seems to negate this insight—but the novel itself, Atonement, seems to be trying to fulfill it.