“Man explored the physical world in the dreaming state long before he explored it physically. Such dreams gave him the assurance that other lands existed outside of his own, and spurred him onward into those physical expeditions in which the species has always taken a particular delight.
“A man or woman might [be] while dreaming suddenly in strange territory, looking at the sky from a different viewpoint, with, say, a familiar river nowhere in sight, and with a mountain where ordinarily a plain might be. This was in a way as startling an experience as it would be to you to find yourselves on some distant planet. (You do, for that matter, explore space in the same fashion, and on at least some occasions your own “visitors from outer space” are dream travelers from other dimensions of reality.)
“In such a fashion, man learned the location of the oceans upon the earth – or at least was given the assurance that such large bodies of water existed, along with clues as to their locations, and the placement of the stars overhead.”
(Dreams, “Evolution” and Value Fulfillment Vol 2, Session 934)