My aim in this paper is to discuss the topicality of Merton’s thesis with a twofold meaning: as an idea which has its own place in the sociology of science and as an idea which is currently in its area of research. Merton asserts that the development of science in 17 th century England was aided by the Puritan ethic. This does not means that science was caused by Puritanism, but only that Puritanism provided major support for the scientific activity. Because secularization and integration were two complementary processes, the relationship between science and religion was not simple. I connect Merton’s thesis with Weber’s thesis about Protestantism and capitalism and try to see it in the light of the cultural climate of its time. Finally, I argue that Merton offers a unified analysis of science as a social institution.