It is generally agreed that the Middle Ages preserved for the use of later times the science of the ancients. Therein lies both the scientific achievement and the scientific failure of the medieval civilization. . . .
What the Middle Ages took over they did not very much enrich. Indeed so small was their own contribution that historians of science are apt to regard the Middle Ages as something of a pause. . . .
Thus some advance on planes both purely intellectual and technical there was; yet taken together and placed against the vast panorama of medieval life, or indeed against the achievements of Greek and Hellenistic science in the fourth century B.C., or with the scientific activity of the seventeenth century, all these achievements are bound to appear very poor. Why then this poverty?
To this question many answers can be and have been given. But what most of them boil down to is the absence in medieval life of what I should be inclined to call scientific incentives. Students of science sometimes differ about the true inspiration of scientific progress. Some seek and find it in man's intellectual curiosity, in his desire to understand the workings of nature. Others believe that scientific knowledge grew and still grows out of man's attempts to improve his tools and his methods of production; that, in short, scientific truth is a by-product of technical progress. I do not want here to take sides in this particular controversy; what I want to suggest is that the Middle Ages were doubly unfortunate in that both the inspirations, the intellectual as well as the practical, failed more or less.
The easiest to account for is the intellectual. The Middle Ages were the age of faith, and to
that extent they were unfavourable to scientific speculation. It is not that scientists as such were proscribed. For on the whole the persecution of men for their scientific ideas was very rare: rare because men with dangerous ideas, or indeed with any scientific ideas at all, were themselves very rare; and it is indeed surprising that there were any at all. This does not mean that there were no intellectual giants. All it means is that in an age which was one of faith, men of intellect and spirit found the calls of faith itself--its elucidation, its controversies, and its conquests-a task sufficient to absorb them. To put it simply, they had no time for occupations like science.
In fact they had neither the time nor the inclination. For even if there had been enough men to engage in activities as mundane as science, there would still be very little reason for them to do so. In times when medieval religious dogma stood whole and un- shaken the intellectual objects and the methods of science were, to say the least, superfluous. The purpose of scientific enquiry is to build up piecemeal a unified theory of the universe, of its origin and of its working. But in the Middle Ages was that process really necessary? Did not medieval man already possess in God, in the story of Creation and in the doctrine of Omnipotent Will, a complete explanation of how the world came about and of how, by what means and to what purpose, it was being conducted? Why build up in laborious and painstaking mosaic a design, which was already there from the outset, clear and visible to all?
So much for intellectual incentive. The practical incentive was almost equally feeble. Greater understanding of nature could not come from technical improvements, chiefly because technical improvements were so few. Medieval occupations continued for centuries without appreciable change of method. After the great period of initial development, i.e., after the late eleventh century, the routine of medieval farming in the greater part of Europe became as fixed as the landscape itself. In the history of the smithies, the weaving shops, or the potteries, there were occasional periods of innovation, but taking the Middle Ages as a whole technical improvement was very rare and very slow. For this medieval economic policy was largely to blame. In the course of centuries economic activities got surrounded with a vast structure of bye-laws and regulations. . . . For bye-laws were as a rule based on the technical methods in existence when they were framed; and once framed they were to stand in the way of all subsequent change.
What is more, so deeply ingrained was the spirit of protection that in every local trade the technical methods were treated as a secret. . . . The men of the Middle Ages were unable to do more than they did because they were lacking in scientific incentive. What they achieved in advancing the practical arts of humanity or in preserving and transmitting ancient learning, they did in so far and as long as they were not typically medieval.
Source: Michael Postan, “Why Was Science Backward in the Middle Ages?” in A Short History of Science: Origins and Results of the Scientific Revolution (London: Routledge and Kegan Paul), pp. 10-17.