Sociology has increasingly drawn on concepts from the cognitive sciences to better theorize and measure culture, particularly nondeclarative personal culture beneath the level of conscious awareness. Despite several advances, these “cognitive cultural” concepts are drawn on selectively, and limited work has attempted to assemble them into a coherent ontology, leading to conceptual murkiness and ambiguous use of terms. This article synthesizes literature on culture and cognition to theorize four interrelated but distinct levels of cultural knowledge beneath the level of explicit discourse. Using emergence theories from the philosophy of science, I theorize how these levels relate to each other, as well as to discourse and public culture. I then illustrate their value as units of analysis using the empirical case of American religious understandings. This ontology provides a necessary groundwork for improved discussions of how culture works, the relation of culture and cognition, and methods for studying nondeclarative personal culture.