The : tales of sleepwalkers and secrets of the body in seventeenth-century England.

Seventeenth-century readers were fascinated by marvellous tales of people known as the who rose up in their sleep, performed daily chores and attempted dangerous feats, such as clambering onto rooftops. On account of their uncanny nature, commentators noted that sleepers could be mistaken for spectres or those who had been bewitched. Depictions of the were also influenced by the , which had argued that they were acting under the influence of demons and would fall if their Christian name was called. Medical texts explained this behaviour in terms of the escape of hot vapours within the body, the powers of the imaginative faculty, and the impairment of common sense during sleep. While this explanation was widely accepted, in the 1650s it was challenged by alternative views from esoteric writings, which conceptualised the movements of sleepers in terms of mystical powers within the body.