Although often conceptualized in contradictory terms, the common assumption that natural and supernatural explanations are incompatible is psychologically inaccurate. Instead, there is considerable evidence that the same individuals use both natural and supernatural explanations to interpret the very same events and that there are multiple ways in which both kinds of explanations coexist in individual minds. Converging developmental research from diverse cultural contexts in 3 areas of biological thought (i.e., the origin of species, illness, and death) is reviewed to support this claim. Contrary to traditional accounts of cognitive development, new evidence indicates that supernatural explanations often increase rather than decrease with age and supports the proposal that reasoning about supernatural phenomena is an integral and enduring aspect of human cognition.