"Great additions have of late been made to our knowledge of the past; _the long conspiracy against the revelation of truth has gradually given way,_ and competing historians all over the civilized world have been zealous to take advantage of the change. The printing of archives has kept pace with the admission of enquirers; and the total mass of new matter, which the last half-century has accumulated, amounts to many thousands of volumes. In view of changes and of gains such as these, it has become impossible for the historical writer of the present age to trust without reserve even to the most respected secondary authorities. The honest student finds himself continually deserted, retarded, _misled by the classics of historical literature_, and has to hew his own way through multitudinous transactions, periodicals and official publications in order to reach the truth. "Ultimate history cannot be obtained in this generation; _but, so far as documentary evidence is at command, conventional history can be discarded, and the point can be shown that has been reached on the road from one to the other._" The italics in this passage are ours, but the ideas they emphasize will serve to show how necessary it is for most of us to give up the supposed historical truth of the preceding generations and have an open mind for the newer ideas that are coming in as the result of the renewed consultation of original documents and primal sources of information. The present volume is written entirely with the idea of bringing out the facts of the relations of the Popes and the Church and the ecclesiastics, especially of the centuries before the reformation, to science and to scientific education. My own position as a professor of the history of medicine has necessarily made medical science very prominent in the book. This, however, far from being a disadvantage, is really an {26} advantage, since the physical sciences of the medieval times gathered mainly around medicine, and it was chiefly physicians and medical students who devoted most time to them. After a detailed study of the history of medical science in the Middle Ages as well of its allied sciences, it becomes very clear that there was no trace of Papal or Church opposition to science as science, and, on the contrary, liberal patronage, abundant encouragement, and even pecuniary aid for the development of scientific education in every way.