Early Modern Theories

Abstract

Most authors in the Renaissance period still followed the Aristotelian and medical accounts of sleep. On the other hand, there were also thinkers who argued that sleep does not affect the highest spiritual part of the soul. Marsilio Ficino put forward this idea in his Neoplatonic philosophy, and it was repeated by representatives of occultist natural philosophy from Paracelsus to Fludd (1). The controversy about cognitive activity in sleep continued in the seventeenth century around Descartes’s thesis that conscious thinking must go on even during dreamless sleep. He claimed that the intellectual soul must be thinking incessantly. This was not favourably received, and the empiricists regarded such a claim as obviously absurd (2).