Viewed in the long perspective, science shows a history of continuity and cumulation from the earliest prehistory of man to the present. However, this history has been marked by quite different rates of development in different times and places. It is this unevenness in its progress, viewed in terms of shorter perspectives, that calls for explanation by the sociology of science. As the sociology of science has itself made progress, a few basic principles of explanation have come to appear sound. One is the principle that no single cultural, social, or psychological factor, such as religion or economic forces, can account for the growth of science as a whole or any of its components or subsciences. Another such point is that not even any single combination of factors, such as the religious and the economic, or the political and the educational, is sufficient for the tasks of the sociology of science. This is not to say that there are not some combinations of factors more favorable than others for certain kinds of specific development in science, as our discussion of the Protestant ethic will illustrate. There definitely are such favorable combinations, and the sociology of science has improved its ability to discover them by accepting the principle that certain types and rates of development may come from one set of factors (or one set of values of these factors taken as variables) and that other types and rates may come from a different set of factors (or a different set of variables-values).
The following discussion will consider some of the major factors that affect the development of science. They exert their influence on science alwaysin combination, and the relative weight of the influence of each may vary in different specific instances.