Morpheus is the pagan divinity that personified sleep in Greco-Roman mythology, while in the Bible, sleep is a divine gift through which God speaks to us. It will be from the early Middle Ages that sleep and consequently dreaming begins to be associated with elements of perdition, as in the Divine Comedy where Dante has lost the "diritta via" and is confused and lost in sleep. Love confusion and confusion in Shakespeare's A Midsummer Night's Dream and life as a dream that we only wake up when we die, according to Calderón.

Dreaming as something dangerous that begets monster and superstition, the territory of the nightmare that drives us crazy. And from the dreamlike world of the romantics to the bourgeois snooze and a restful nap, but under the watchful eye of guilt, because Christian morality does not want us unemployed or with a released consciousness.