Final answer:
Sir Edward Burnett Tylor defined religion as the belief in supernatural beings, which is a narrower view compared to other theorists like Emile Durkheim who saw religion as a broader social institution.
Step-by-step explanation:
The theorist who defined religion as the belief in spiritual beings was Sir Edward Burnett Tylor. While his contemporary Sir James Frazer also studied religious beliefs, it was Tylor who minimally defined religion as “the belief in supernatural beings.” This contrasts with other theorists such as Emile Durkheim, who saw religion as a broader system including beliefs, practices, and social institutions that foster community cohesion.
Tylor's definition sparked significant anthropological discourse and research, paving the way for more nuanced understandings of religion and spirituality. While his definition might be considered narrow in modern conceptualizations of religion, it remains an important historical perspective in the study of religious belief systems.
Anthropologists today recognize a more complex picture of religion, often including Clifford Geertz's conception of religion as a system of symbols, and Durkheim's empirical approach to religion as an institution related to “sacred things” with beliefs, practices, and social organization.