Beliefs about dreams, in Renaissance England, were wide-ranging; for example, the British Library illustrates: 

“In the Elizabethan period…there were anxieties about the nature and interpretation of dreams. Many questioned whether dreams were supernatural or whether they originated in the dreamer. If the former, were they angelical or demonical? And if the latter, did they originate in the soul, the mind or the body? Concerns ranged from the reliability of discerning meaning from dreams and of discerning true dreams from false, to growing scepticism about their prophetic capacity at all.”

However, prevailing religious and physiological wisdom held that dreams were visions of the future. (Many were convinced that unlocking the meaning of dreams could allow them to see the future.) According to Dr. Will Tosh: 

“​​Physicians had long assumed that dreams functioned diagnostically, revealing to a doctor the state of a patient’s health. It was widely believed that dreaming of particular things—losing an eye, or bloody teeth, or seeing a hare—portended death, either one’s own or someone else’s. Chiefly, of course, dreams seemed to offer the faithful a space and a language with which to communicate with God.” 

However, predicting modern dream theory, Thomas Nashe’s The Terrors of the Night (1594) rejected the theory “that dreams had supernatural origins and mystical meanings.” Dramatist, essayist, and collaborator of Shakespeare’s on the earlier history plays, Nashe: 

“…poured scorn on those who saw prophetic significance in night-time visions, arguing instead that ‘a dream is nothing else but the echo of our conceits in the day’. In a metaphor that unconsciously anticipated modern cognitive science, he compared ‘the working of our brains after we have unyoked and gone to bed’ to ‘the glimmering and dazzling of a man’s eyes when he comes newly out of the bright sun into a dark shadow.’”