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 work is a natural-scientific and philosophical treatise that elucidates the purpose and physiological mechanisms of respiration, as well as alternative cooling functions, in the maintenance of animal life. The author begins by critically examining the theories of respiration proposed by predecessor natural philosophers, such as Democritus, Empedocles, and Plato, pointing out their physical and teleological contradictions, particularly regarding the structure of fish and temperature changes. Next, the text posits a unique view of life wherein the vital heat (fire) residing in the heart is essential for maintaining life, requiring constant cooling to prevent its extinction or smothering. Based on this principle, the author comparatively analyzes diverse cooling systems suited to various habitats and anatomical structures, such as the inhalation and exhalation of air through the lungs in terrestrial animals, and the intake of water through the gills in aquatic creatures. Respiration is physically explained using the metaphor of a bellows, driven by the expansion and contraction of internal heat. Finally, the treatise defines life, aging, and death as processes governed by the preservation or loss of this cooling function, concluding with a discussion on how the inquiries of natural philosophy intersect with the medical study of health and disease.