Probably the most important work that the Popes did for medical science in the Middle Ages was their encouragement of the development of a hospital system throughout Christianity. The story of this movement is not only interesting because it represents a coordination of social effort for the relief of suffering humanity, but also because it represents the provision of opportunities for the study of disease and the skilled care of the ailing such as can come in no other way. Those who are familiar with the history of medicine, and especially of surgery, know that a great period of progress in these departments came during the thirteenth century. The next two centuries indeed represent an epoch of surgical advance such as was probably never surpassed and only equalled by the last century. This seems much to say of a medieval century 700 years ago, but our chapter on surgery will, I think, amply justify the assertion. The reasons for this great development in surgical knowledge are properly understood only when we come to realize that there was a corresponding development in hospital organization. These two features of medicine always go hand in hand. The hospitals, as might be expected, preceded the surgical development, and owed their great progress at this time mainly to the Popes.
The city hospital as we have it at the present time, that is, the public institution meant for the reception of those suffering from accidents, from acute diseases of various kinds, and also for providing shelter for those who have become ill and have no friends to take care of them, is an establishment dating from the beginning of the thirteenth century. It will doubtless be a surprise to most people to be told that the modern world owes this beneficent institution to the fatherly watchfulness, the kindly foresight, and the very practical charity of one of the greatest of the Popes, whose name is usually associated with ambitious schemes for making the Papacy a great political power in Europe, rather than as the prime mover in what was probably the most far-reaching good work of supreme social significance that was ever accomplished.
At the beginning of the thirteenth century, mainly as the result of those much abused sources of many benefits to mankind in the Middle Ages, the Crusades, the people of Europe had begun to dwell together in towns much more than before. It is closeness of population that gives rise to the social needs. While people were scattered throughout the country diseases were not so prevalent, epidemics were not likely to spread, and the charitable spirit of the rural people themselves was quite sufficient to enable them to care for the few ailing persons to be found. With the advent of even small city life, however, came the demand for hospitals in the true sense of the word, and this need did not long escape the watchful eye of Innocent III. He recognized the necessity for a city hospital in Rome, and in accordance with his very practical character and wonderful activity, at once set about its foundation.
James J. Walsh, The Popes and Science (1908)