The period prior to the dispersion of the fol lowers of Pythagoras (q.v.) (e..500 n.c.) is some times called the sacred period of medicine. It etas followed by the philosophical period, inseparably linked with the name of Hippocrates (q.v.) (n.c. 460-c.357), the first great apostle of rational medicine. He classified diseases into epidemic, endemic, and sporadic; he wrote extensively on surgery (though ignorant of dissection), on ob stetrics, hygiene. regimen, and on climatic influ ences; and his works display an immense range of knon ledge and high powers of description.
From the time of Hippocrates, for several cen turies, we find medical beliefs crystallizing about several schools or systems. The Dogmatic or rationalistic school of Hippocrates, founded by his sons, Thessalus and Draco. and his son-in law, Polybius, based its principles of practice on theories derived from known facts and obser vations, and regarded maladies as units from their beginning to their termination; that is, they recognized diseases as distinct entities. The Em pirics, on the other hand, taught that remedies could only be suggested by experience. Their school was founded. according to Celsus, by Sera pion. a pupil of Hierophilus, mentioned later in this article. The Methodists occupied a position somewhere between the Empirics and Dogmatists, and the Eclectics chose, or pretended to choose, from each system what suited them. and adhered to none.
The philosophic period ended and the anatomic priod began with the foundation of the Alex andrian Library, after the death of Alexander the Great, by Ptolemy, one of his lieutenants. This was in n.c. 320, and the centre of medical thought and teaching was non' shifted to Alex andria. Here the Ptolemies gathered about them the learned men of the day. Although Egyptian prejudice was strong against it, Ptolemy encour aged dissection of the human body. Among the famous teachers of Alexandria were llierophilus and Erasistratus (q.v.). The former is supposed to have been the first to dissect a human body, and between them they made ninny notable dis coveries concerning the structure of the brain, eye. heart, and intestinal canal. Erasistratus died about B.C. 2S0. During this period medical thought was practically divided into two schools, the Dogmatist and the Empiric.
The first native Roman writer on medicine was Celsus (q.v.), born at about the time of Christ. His work. Ile Medieina, gives a sketch of the his tory of medicine up to his time, and the state in which it then existed. lie followed the teachings of Hippocrates and exercised a dominant influence until Galen (q.v.) (130-c.201) totally supplanted him. Galen wrote over a hundred works, some of them on anatomy. He described every hone in the human body, and the functions of the muscles; he recognized two kinds of nerves— those of sensation. which he thought came from
the brain, and those of motion. which he believed to originate in the spinal marrow. He divided the body into the cranial, thoracic. and abdominal cavities, whose proper envelopes he described.
Galen strove to popularize the study of anatomy, with but little success. and with his death came the end of the anatomical period and the end for several centuries of medical progress.
The first names of any renown that occur after the death of Galen are those of Uribasius, Alex ander of Tralles, ..Etins, and Paulus ..Egineta, who flourished between the fourth and seventh centuries. They were all zealous Galenists. With the death of Paulus the Greek school may be said to have ended, for after his time no works of any merit were written in this language.
Arabian medicine was an offspring of the Greek, through the Nestorian monks, who settled in Persia and Arabia in the sixth century, and established many schools of ]earning. Fragments of the sect still remain in these countries. By the seventh century Arabian physicians were in high repute. The earliest Arabic nyder on medi cine was Alumni, who was contemporary with Paulus, hut the most celebrated physicians of this school were Rhazes, who lived in the ninth century and was the first to describe smallpox; Avicenna (q.v.), of the eleventh century, whose Canon Medicinw embraced all that was then known of medicine and the collateral sciences; Albueasis, whose works on surgery were the standard for several centuries; Avenzoar; and Averroi-;s. W110 lived in the twelfth century and was equally celebrated as a physician and a phi losopher. The works of Hippocrates and Galen, which,together with those of Aristotle. Plato. and Euclid. were translated into Arabic in the ninth century, formed the basis of their medical knowl edge; but the Arabian physicians did good ser vice to medicine by introducing new articles from the East into the European materia mediea, for example, rhubarb, cassia. senna, and camphor, and in making known the first elements of phar maceutical chemistry, such as distillation, and the methods of obtaining various metallic oxides and salts. During this period that part of Eu rope not in the hands of the Saracens was sub jected to successive invasions of northern bar barians. and medicine, as other arts, was at a standstill. There was a brief period of quiet during the reign of Charlemagne. when medical practice seems to have again passed into ecclesiastical con trol, and from the ninth until the thirteenth century the Jews (who acquired their learning from the Saracens) shared with the clergy the art of healing.