Bringing Ritual to Mind explores the cognitive and psychological foundations of religious ritual systems. Participants must recall their rituals well enough to ensure a sense of continuity across performances, and those rituals must motivate them to transmit and re-perform them. Most religious rituals the world over exploit either high performance frequency or extraordinary emotional stimulation (but not both) to enhance their recollection (the availability of literacy has little impact on this). But why do some rituals exploit the first of these variables while others exploit the second? McCauley and Lawson advance the ritual form hypothesis, arguing that participants’ cognitive representations of ritual form explain why. Reviewing evidence from cognitive, developmental and social psychology and from cultural anthropology and the history of religions, they utilize dynamical systems tools to explain the recurrent evolutionary trajectories religions exhibit.