The title provided the key. John didn't use the word "imagine" to mean simply "suppose" or "assume." He believed in imagination as a form of magic; if enough people believed something to be true, the reality would manifest itself.

One of the inspirations behind the song was a book on prayer that Dick Gregory had given him. Gregory can no longer remember the title or the author but knows that John would call him to discuss the theories it was promoting.

"It spoke about forgiveness, love, and the power of the mind," he says. "It had prayers in it, but not the kind that you would hear in a church. They were the prayers of the power within, the power that you can't release if you are hold-ing hatred, bitterness, or pain."

This was the concept behind the 1969 "War Is Over-If You Want It" campaign, when he and Yoko had posters put up at significant sites in ten world cities announcing WAR IS OVER! IF YOU WANT IT.

I wonder if the book was Grapefruit lol