Praxagoras Biography (4th century B.C.-4th century B.C.)
Praxagoras, a descendant of Asclepius, was a resident of Cos in Greece. He isbelieved to have been born around 340 BC, although some historians have placed his date of birth as late as the last third of the fourth century. His father, Nicharchus, was an eminent physician who, according to Galen, held the theory that the arteries contain only air, while the veins contain blood. Thistheory was later also expounded by Praxagoras.
Praxagoras, came to be regarded in antiquity as the most famous member (afterHippocrates, who was probably somewhat older than Praxagoras) of the Coan School. Galen ranked Praxagoras beside Hippocrates and Diocles among the famousphysicians of the old school. Later medical historians classified Praxagorasas a follower of the logical or dogmatic school, which advocated rigid doctrine rather than investigation. (The dogmatists divided medicalscience into five branches: physiology, etiology, hygiene, semeiology, and therapeutics.) Praxagoras was the author of a book on the diseases of foreign lands, which suggests that he may have left his native country to travel abroad; this has led some scholars to conclude that Praxagoras had mainly a theoretical interest in medicine, though his reputation as a surgeon suggests thathe could be rather daring in his medical procedures. He exerted tremendous influence on the development of Greek medical thinking, having been the teacherof some very illustrious physicians, including Plistonicus, Xenophon of Kos,and Herophilus (credited with differentiating the cerebrum and cerebellum, and with counting the pulse using a water clock). Praxagoras's work was widelyknown throughout antiquity. In the third century BC, the Stoic philosopher Chrysippus made reference to Praxagoras in discussing the origin of the nervesin the heart, suggesting that the latter was recognized as an outstanding authority on medical questions even in the third century BC. Yet another reference to Praxagoras appears in the first century BC by Krinagoras. Galen, who wrote a special book on the humors based on the theory of Praxagoras, attempted to show that Praxagoras's ideas were an extension of those of Hippocrates.Galen's opinion of Praxagoras is highly sympathetic, with Galen stating thatone must praise those individuals who explain the truth once it is found andwho make appropriate additions. References to Praxagoras also occur in the codex Crameri, the codex medicorum Laurentianus, and the codices Graeci Bonnonenses. One of Praxagoras's letters has also been preserved. Based on extant fragments of his writing, it is believed that Praxagoras authored at least 12 books, though the actual count is uncertain.