This article rejects the ambitious proposal made by cognitive sociology of science of explaining science, including the content of its theories, as a byproduct of social causes. Besides, this article examines why there is a clear and pronounced gap between the view of science, strongly internalist, endorsed by the vast majority of natural scientists, and the externalist view - everything in science is explainable by means of social causes - adopted by social constructivism. This paper holds the thesis that the approach adopted by the cognitive sociology of science introduces implicitly Manheim's concept of unmasquing in so far as it disqualifies the understanding scientists have of what they do: they are determined by factors in their research routines, but they think they are moved by reasons. The retaking of this old explanatory tradition in social sciences - that of unmasking the way agents see themselves and give meaning and reasons to their actions - needs to be critically evaluated by a metascience interested in discovering the typical ways reasons and factors can interact and in avoiding the temptation of reducing the epistemic to the social.
Epistemic reasons; Psychological and social factors; Human action; Unmasking; Manifest function; Latent function