Source edition
Aristotle. Aristotelis Opera, Volume 3. Bekker, Immanuel, editor. Oxford: Oxford University Press, 1837.
Source data
A Digital Corpus for Graeco-Arabic Studies · CC BY-SA 4.0
Cloned and adapted by Humanitext, with ongoing edits.
Summary
This treatise explores the scientific and physiological mechanisms of dreams and investigates which part of the soul they belong to. The author, Aristotle, begins by demonstrating that dreaming belongs not to the intellect, but to the faculty of perception—specifically, the faculty of imagination (phantasia). He then explains the physiological phenomenon of "residual movement" that persists in the sense organs even after the external stimulus has gone, using examples such as afterimages and reflections in mirrors, while also explaining how emotions or illness can cause perceptual errors. Finally, he describes how, during sleep when external stimuli decrease, these residual movements retreat to the sensory center and present themselves as images, defining this process as the essence of dreams. The work systematically accounts for both the generation of dreams and the bodily conditions of those who do not dream.