Prior to the classical era, and continuing for some non-literate societies into modern times, dreams were considered a vehicle used by gods to reveal truths to sleeping humans. Ancient Egyptians believed that dreams were the best way to receive divine revelation, and thus they would induce (or "incubate") dreams. They went to sanctuaries and slept on special "dream beds" in hope of receiving advice, comfort, or healing from the gods. Sigmund Freud, well-known to many for his innovative interpretations of dreams, wrote that dreams "serve the purpose of prolonging sleep instead of waking up. Dreams are the GUARDIANS of sleep and not its disturbers." 
Prior to the classical era, and continuing for some non-literate societies into modern times, dreams were considered a vehicle used by gods to reveal truths to sleeping humans. Ancient Egyptians believed that dreams were the best way to receive divine revelation, and thus they would induce (or "incubate") dreams. They went to sanctuaries and slept on special "dream beds" in hope of receiving advice, comfort, or healing from the gods. Sigmund Freud, whose dream studies focused on interpreting dreams, not explaining how or why humans dream, did comment that dreams "serve the purpose of prolonging sleep instead of waking up. Dreams are the GUARDIANS of sleep and not its disturbers." Following the 1953 publication of the Aserinsky and Kleitman paper, which announced REM sleep as a distinct phase of sleep and associated REM to dreams, dream research has sought grounding in the methods of conventional modern science.
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well-known to many for his innovative interpretations of dreams, wrote
whose dream studies focused on interpreting dreams, not explaining how or why humans dream, did comment
A
Following the 1953 publication of the Aserinsky and Kleitman paper, which announced REM sleep as a distinct phase of sleep and associated REM to dreams, dream research has sought grounding in the methods of conventional modern science.