Abstract. Religion persists, even within enlightened secular society, because it has adaptive functions. In particular, Ralph Wendell Burhoe's theory holds that religion is the repository of cultural wisdom that most encourages mutual altruism among nonkin, long-term social survival, and human progress. This article suggests a variant of Burhoe's rationalized naturalistic view. Cognitive theism is a proposal that secularists sometimes take religion on its own terms by suspending disbelief about God. If we consider particular human capacities and limitations in memory, perception, personality, and motivation, the regulated “mind expansion” of cognitive theism may help us to evaluate, coordinate, and invigorate things in a modern environment. In this environment, communicative and travel technologies have led to a high loading of consciousness with a historically unusual diverse range of experiences and responsibilities, a high rate of cultural change relative to biological evolution, and a tendency to factionalize. Burhoe's extension of the concept of symbiosis to the coevolution of culture and genes is modified here in recognition of individual differences and of individuals' potential for choosing strategies, recombining in groups, and learning. In human biocultural symbiont pools, cultural phenomena can evolve while changing partners in a dance with genetic substrates, a dance that broadly supports these substrates. In the context of diversity and incessant change in a large predominantly secular community, Judeo-Christian monotheism can have a valuable advisory unifying function.