The question at page 242 is "What's the difference between what you WANT TO believe and what you do?" That is a slightly different query. Patra wants to believe desperately in the tenets of Christian Science, and, in doing so, she is able to ignore the seriously ill condition of Paul. Linda, too, wants to believe that Patra and Leo are doing the right thing and even though she has increasing doubts, she too, is able to ignore all the desperate signs. Another example: early in the book, we are told that Linda's mom baptized Linda in a basin when she was very young and said "I wished I believed in this shit". So it seems that going through the motions of what is consistent with what you want to belief and what you do comes down to the same thing. Later, on the same page, Linda asks, "What's the difference between what you think and what you end up doing?" For Mr. Grierson, he thought about doing the things that Lily falsely accused him of and in his eyes, it made him no less guilty than if he had done them.