The prominent Swedish scientist and assessor of the Royal Board of Mines, Emanuel Swedenborg, underwent a profound psychological and spiritual transformation documented in his private 'Drömboken' (Journal of Dreams). Over several months, Swedenborg experienced intense, terrifying nightmares, ecstatic sleep paralysis, and vivid hypnagogic visions that eventually led him to abandon his scientific career entirely. He claimed these dreams opened his inner sight, allowing him to converse directly with angels and spirits in a persistent alternative reality.

Swedenborg's detailed descriptions of the correspondence between the physical world and the spiritual subconscious profoundly influenced William Blake, Charles Baudelaire, and W.B. Yeats. His dream-theosophy provided Romantics and Symbolists with a structural vocabulary to treat the dream state as a portal to higher cosmic poetry.