Source edition
Galen. Claudii Galeni Opera Omnia, Volume 4. Kühn, Karl Gottlob, editor. Leipzig: Knobloch, 1822.
Source data
A Digital Corpus for Graeco-Arabic Studies · CC BY-SA 4.0
Cloned and adapted by Humanitext, with ongoing edits.
Summary
This work is a medical and philosophical treatise in which Galen investigates the function and purpose of breathing, which is essential for sustaining life. The author begins by reviewing past theories regarding the utility of respiration and questions whether the substance or the quality of the inhaled air is required. He systematically critiques rival schools, such as those of Erasistratus and Asclepiades, by utilizing empirical observations and experiments regarding breath-holding. He then addresses the conflict between the theories of cooling and cherishing the heat by using the physical analogy of a burning flame. Through further observations of clinical cases, animal characteristics, and physiological experiments, he demonstrates that respiration is necessary for maintaining innate heat, cooling, and discharging smoky wastes. Finally, through experiments on the brain and arteries, he concludes that the primary purpose of breathing is the preservation and regulation of innate heat, while its secondary purpose is to nourish the psychic pneuma.