Source edition
Theophrastus. Theophrasti Eresii Opera, Quae Supersunt, Omnia. Wimmer, Friedrich, editor. Paris: A.F. Didot, 1866.
Source data
Open Greek and Latin · CC BY-SA 4.0
Cloned and adapted by Humanitext, with ongoing edits.
Summary
This scientific and philosophical treatise investigates the physiological and physical mechanisms behind the phenomenon of vertigo (ilyngos). The author attributes the primary cause of vertigo to the circular motion of air (pneuma) or uneven moisture within the head, as well as the head's voluntary rotation. In the first half, the text explains the varying intensity of vertigo through geometric and visual factors, utilizing concrete examples such as the comparison between raw and boiled eggs, and the tilting of the body when running in a circular path. The second half analyzes how looking down from heights or staring intensely at a single spot agitates and separates the bodily fluids in the brain, incorporating the philosophy of Heraclitus. Ultimately, the work discusses daily bodily factors such as hunger, satiety, and the movement of fluids upon standing up, presenting a comprehensive view of vertigo as a dynamic interaction between vision and bodily fluids.