Roger Bacon has often been victimized by his friends, who have exaggerated and distorted his place in the history of mathematics. He has too often been viewed as the first, or one of the first, to grasp the possibilities and promote the cause of modern mathematical physics. Even those who have noticed that Bacon was more given to the praise than to the practice of mathematics have seen in his programmatic statements an anticipation of seventeenth-century achievements. But if we judge (...) Bacon by twentieth-century criteria and pronounce him an anticipator of modern science, we will fail totally to understand his true contributions; for Bacon was not looking to the future, but responding to the past; he was grappling with ancient traditions and attempting to apply the truth thus gained to the needs of thirteenth-century Christendom. If we wish to understand Bacon, therefore, we must take a backward, rather than a forward, look; we must view him in relation to his predecessors and contemporaries rather than his successors; we must consider not his influence, but his sources and the use to which he put them. (shrink)