The Committee of Elders calls upon the Receiver of Memory for help and advice.
In the community there is a strictly enforced concept of Sameness. As a result, there is no written history or shared memory. All of the memories are stored by the Receiver of Memory, a special Elder who knows everything that has ever happened.
"It's the memories of the whole world," he said with a sigh. "Before you, before me, before the previous Receiver, and generations before him." (ch 10, p. 77)
Because no one in the community knows any history, the Elders rely on the Receiver of Memory to advise them. For example, if they want to increase the population to have more workers, they might ask the Receiver. In this case, he suggested that they do not change population numbers because he had memories of starvation and famine, and other consequences of overpopulation. They trust the Receiver.
The concept of a Receiver is extremely important to the community. Without this role, they cannot have Sameness because they have to have one person who knows the history so they don't make mistakes repeating it.
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Lowry, Lois (1993-04-26). The Giver (Newbery Medal Book). Houghton Mifflin Harcourt. Kindle Edition.