But there was another branch of practical science which, if not created by Aristotle, was certainly promoted by his studies in zoölogy and botany. We still regard these sciences as a necessary introduction to medicine, and we may be sure that in old days the order of such studies was not different. The distinction of being the father of rational medicine need not be added to the other crowns which adorn the great sage. Both Greeks and moderns are unanimous in awarding that honour to Hippocrates of Kos, where there was an old guild of physicians, of which he was neither the first nor the last of his name. Hence the works now known as those of Hippocrates may not all be the actual writing of one man; for as with Aristotle, so with Hippocrates, there was a school, and the pupils followed in the master’s path. But there is no doubt whatever as to the character and tone of his teaching. We find even a literary grandeur in his prose, that is not the writing of any but a great master. The famous opening of his _Aphorisms_ is probably known to most of my hearers. But it is a puzzle to translate without dull amplification. Here is a paraphrase: “Life is brief, yet craft grows slowly; the right time is instantaneous, yet experience is treacherous, and decision burdensome.” As is the style, so is the thinking out of the problems before him. Starting from hygiene as the proper basis of medicine, he thinks those should be regarded as the earliest physicians who improved the food of primitive men by crushing grain, by cooking meat, and by selecting edible vegetables. From that time onward, there was growing up an experience of what was healthy and what the reverse. It is this experience which he seeks to systematise by careful observation and so to establish laws of hygiene, and the probable natural prophylactics or remedies afforded by air, water, and climate. He analyses with care the proper aspect for a town and decides (in the latitudes which he knew) for the eastern as the best and the western as the worst. He discusses the quality of the water supply, and lays great stress upon its altitude. He sets down careful clinical records of cases of fever--typhus, puerperal, malarious, and the like. The results of this rational treatment of disease were far-reaching and permanent. To cite to you the cloud of witnesses would be mere waste of time. But I will take one instance, closely related to the history of my great college and of medicine in Ireland.[36] The founder of the College of Physicians in Ireland under the Cromwellians and Charles II. was John Stearne, a grand-nephew of Archbishop Ussher, himself also a theologian and metaphysician. Driven out of Ireland by the stress of the Rebellion of 1641, and educated in all the medical learning of Cambridge, he returned with the Cromwellian restoration of order and became not only a Fellow of his college (along with some eminent Puritans from Harvard) but a distinguished practitioner in Dublin.