The text sets out to contribute to the definition, delimitation and autonomy of the science of religion, adopting this terminology in the singular. It proposes a science for the study of religion, establishing its way of approaching this object. It argues that it is possible to establish a science of religion with its own epistemological status, capable of dealing with the study of religion, even if it does so with the help of other human sciences. The research in question is that no other science can have religion as its object than the science of religion. And this science needs to have its field of action defined. We therefore propose the general lines of this field of action, without pretending to exhaust the subject. We think of religion as a social activity and study it as a social science. On the other hand, religion is seen as an expression of culture internalised in the individual and, therefore, also as a manifestation of subjectivity. It proposes the epistemological status of the science of religion, as a scientific corpus, its autonomy and its method or methods; and works on the specifics of the science of religion, formed by the tripod of belief systems, the community of believers and religious acts.