By looking at the case where science and religion come into direct contact, Leonardo Ambasciano's book An Unnatural History of Religions: Academia, Post-truth and the Quest for Scientific Knowledge (2019) provides a way into the tangle of issues involved in understanding the cultural and cognitive mechanisms that underlie science and religion. In doing so, it lays bare how much there is to do in order to understand real-world interactions between the variety of social institutions that make differing uses of the pre-existing cognitive mechanisms that humans possess. Something of that picture can be understood in terms of the differing ways in which scientific and religious institutions alter patterns of epistemic vigilance. Scientific institutions have a tendency to put the focus upon content vigilance, while religious ones favour source vigilance. The difference is not coincidental. A focus on source vigilance makes maintaining traditions of belief independent of the accuracy of those beliefs – a task that is vital in the case of religious beliefs because their capacity to maintain prosocial behaviour is not connected to their truth.