Hippocrates brought it into repute; whatever he established, Chrysippus overthrew; after that, Erasistratus, Aristotle's grandson, overthrew what Chrysippus had written; after these, the Empirics started up, who took a quite contrary way to the ancients in the management of this art; when the credit of these began a little to decay, Herophilus set another sort of practice on foot, which Asclepiades in turn stood up against, and overthrew; then, in their turn, the opinions first of Themiso, and then of Musa, and after that those of Vectius Valens, a physician famous through the intelligence he had with Messalina, came in vogue; the empire of physic in Nero's time was established in Thessalus, who abolished and condemned all that had been held till his time; this man's doctrine was refuted by Crinas of Marseilles, who first brought all medicinal operations under the Ephemerides and motions of the stars, and reduced eating, sleeping, and drinking to hours that were most pleasing to Mercury and the moon; his authority was soon after supplanted by Charinus, a physician of the same city of Marseilles, a man who not only controverted all the ancient methods of physic, but moreover the usage of hot baths, that had been generally and for so many ages in common use; he made men bathe in cold water, even in winter, and plunged his sick patients in the natural waters of streams. No Roman till Pliny's time had ever vouchsafed to practise physic; that office was only performed by Greeks and foreigners, as 'tis now amongst us French, by those who sputter Latin; for, as a very great physician says, we do not easily accept the medicine we understand, no more than we do the drugs we ourselves gather. If the nations whence we fetch our guaiacum, sarsaparilla, and China wood, have physicians, how great a value must we imagine, by the same recommendation of strangeness, rarity, and dear purchase, do they set upon our cabbage and parsley? for who would dare to contemn things so far fetched, and sought out at the hazard of so long and dangerous a voyage?
Since these ancient mutations in physic, there have been infinite others down to our own times, and, for the most part, mutations entire and universal, as those, for example, produced by Paracelsus, Fioravanti, and Argentier; for they, as I am told, not only alter one recipe, but the whole contexture and rules of the body of physic, accusing all others of ignorance and imposition who have practised before them. At this rate, in what a condition the poor patient must be, I leave you to judge.