primitive religion
Refers to early, non-institutionalized religious beliefs often associated with animism, shamanism, or ancestor worship. Used in academic or comparative religion contexts.
The study of primitive religion is an important field of anthropology.
natural religion
A philosophical or theological concept referring to religion based on reason and the natural world, as opposed to revealed religion. Often contrasted with 啓示宗教 (revealed religion).
During the Enlightenment, natural religion was regarded as the foundation of rational faith.