Page:Greek Biology and Medicine.djvu/155

 LINKAGE WITH THE MODERN TIME From Galen we leap forward to his would- be overthrower, Paracelsus, who cast off the old theories, yet reached back his hand to Hippocrates as a wise practitioner and pro- found observer of the courses of disease, like Paracelsus himself! His younger contempo- rary, Vesalius, investigating with his own hands and eyes, rejected much of the old anatomy, and apparently troubled himself little with medical theory. But Harvey — to mention only one feature of the working of this great intelligence — was harassed by the craving to reconcile the circulation of the blood with the Aristotelian physiology or teleology of the nat- ural parts of man. And if Harvey's dis- covery of the systemic circulation appears as the fruit of investigation and experiment, his pregnant contribution to the theory, or knowl- edge, of generation was in itself an hypothesis (acceptable no longer!), to wit: omne vivum ex ovo. Practice and theory! medicine must have both; and when clinical experience has taught its lessons, the microscope and laboratory be- come the chief means of medical advance. The wise practitioner, though he turn his mind from theorizing, will still be he who proceeds upon some sane working hypothesis. [ 133 ]