their service of the god. In this part of Asia, also, philosophy took its rise. For not only was Hippocrates a philosopher as well as a physician, but the same affirmation can be made of a considerable number of Greek thinkers. Diogenes has just been mentioned. Moreover the two lines of investigation were often parallel in other parts of the ancient world. Empedocles who was a full generation older is supposed to have been a physician. Pythagoras, who lived still earlier, though perhaps not a physician in the strict sense of the word, gave, according to tradition, no little attention to the laws of health and formulated a number of precepts supposed to be conducive to its preservation. Plato, though not a special student of the healing art, shows in many passages of his Dialogues, a considerable degree of familiarity with the subject. Aristotle was the son of a physician and was indebted to his father not only for much of his knowledge, but also for his interest in natural history; while his pupil Theophrastus is regarded as the father of medical botany. Among the Romans we find Pliny paying a good deal of attention to facts or supposed facts in the realm of medicine. The same thing is true of Seneca and still more of Vitruvius, though it would perhaps be as far astray to call him a philosopher as a physician in the strict significance of the terms. Toward the latter part of the second century we are carried back again to Asia Minor to find in Galen of Pergamus, not only a distinguished writer on philosophical subjects, but a man whose reputation as a physician is fully equal to, if not greater than, that of Hippocrates, notwithstanding that he was a man of less native capacity. It may be confidently affirmed that Hippocrates, Celsus and Galen represent the entire healing art until modern times. With respect to Cornelius Celsus, who lived in the reign of Tiberius and who occupies an important place in the history of ancient medicine, it must be said that it is uncertain whether he was really a physician. It is rather more than probable that he was a savant. On the other hand, the question is raised, Why would any one but a practical physician compile a medical work? Could any other person do it successfully? Another singular fact that has added to the difficulty of defining Celsus' position is that even as late as the age in which he lived nearly all the physicians in Rome were Greek freedmen. At any rate the work of Celsus at once sprang into prominence, and though it is only part of an encyclopedic compilation, nothing else remains at the present day. As is the case with not a few other works of antiquity, its connection with modern times hangs by the slender thread of a single manuscript from which all later copies have been made. This portion of the encyclopedia of Celsus has also an important historical value since it gives brief sketches of more than seventy physicians who had lived
