Maurice Blondel’s philosophy makes strong claims about the theological enterprise. Namely, philosophy and theology achieve their fulfillment only in mutual dependence and both court superstition to the extent that they attempt self-sufficiency. This symbiotic relationship drives Blondel’s seminal work Action, which not only deduces a hypothetical necessity for the supernatural from a realist phenomenology but also establishes strictly philosophical exigencies with theological import: a true revelation in sensory signs, a historical Savior as Mediator, and a sacramental practice, a robust response to the Enlightenment critique of the Christian religion.