Recent research on lucid dreams suggests that consciousness exists along a spectrum between sleep and waking, between hallucination and revelation, between dreamworlds and reality.

Until the modern age, most households had two distinct intervals of slumber, known as “first” and “second” sleep, bridged by an hour or more of quiet wakefulness. Usually, people would retire between 9 and 10 o’clock only to stir past midnight to smoke a pipe, brew a tub of ale or even converse with a neighbor.

Others remained in bed to pray or make love. This time after the first sleep was praised as uniquely suited for sexual intimacy; rested couples have “more enjoyment” and “do it better,” as one 16th-century French doctor wrote. Often, people might simply have lain in bed ruminating on the meaning of a fresh dream, thereby permitting the conscious mind a window onto the human psyche that remains shuttered for those in the modern day too quick to awake and arise.