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 treatise by the ancient physician Galen addresses the controversial question of whether arteries naturally contain blood, directly challenging the Erasistratean view that arteries are filled only with pneuma (spirit) and receive blood only upon injury. Galen begins with the empirical observation that blood flows immediately when an artery is wounded, and systematically dismantles the counterarguments of his opponents, who claimed that pneuma escapes first to allow blood's entry. Through logical reasoning and detailed anatomical demonstrations, such as the dissection of mesenteric arteries, he exposes the absurdity of the theory that even a tiny prick could instantly empty the body's pneuma. He employs rigorous experimental methods, including arterial ligation and the insertion of tubes, to prove that arteries expand actively through a force transmitted from the heart. Ultimately, the work combines philosophical dialectic with empirical anatomy to refute both dogmatic and skeptical errors, establishing that blood is indeed naturally present within the arteries.