The original question had to be edited. I would suggest that the book does depend greatly on the memory of mental states. Lennie's dream of tending the rabbits, George's dream of owning a farm, Candy's dream of joining them, as well as Curley's wife's dreams of being in "pitchers" are all significant parts of the narratives. Memories play a haunting role in individual consciousness, as well. George understands how cruel he was to Lennie in the past, while Candy is haunted by the memory of letting someone else kill his beloved dog. Curley's wife feels robbed by the past that denied her a chance to be a success, while Crooks's memory of a life that is not bound by segregation eats away at him. The philosophy of Slim is something that can be seen at nearly instance he speaks. From the first moment he refers to the distinction of George and Lennie being with one another and how rare that is two men travel together to the very end when he reminds George that he "had to do it," Slim's philosophy guides the men on the ranch and serves as a type of moral compass that directs the work and the characters in it. This makes the mental states of individuals such as dreams, memories, or philosophical ideas as essential to the work's being.