The Early Sessions, Books 6 & 7

Because of other procedures I have explained, including the existence of constant telepathy, there is some agreement as to the placement of these objects, or if Ruburt prefers, locations, in space. Now this gives rise to what you may call mass-perception... When you are dealing with dream locations, you are not dealing with mass-perceptions, but with personal perceptions. There is no need therefore for any complicated arrangements calculated to insure agreement between persons as to location in space.

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One of the root agreements upon which physical existence is based is that physical objects have a reality that is entirely independent of any subjective cause; and that these objects, within definitely specified limitations, are permanent.

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All mental life is characterized by divergent perceptions of any given set of sense data that is recognized as Reality, with a capital R. Those who perceive this set of data in such a way that agreement is reached are called sane. But none of you perceives the same reality.