 Followers of St Augustine shared Plato’s doubts about the capacity of sense perception, in particular about its ability to give rise to scientific knowledge. Such knowledge, they held, did not arise from sense perception alone; it required a further input, provided by God himself: a divine illumination. This can be a difficult idea for a modern reader to grasp, since it is easily confused with another belief, which has to do with a supernatural source of knowledge accessed by faith. The two are analogous, insofar as they both involve a divine initiative. The act of faith requires a divine initiative “on the volitional side,” to enable us to accept propositions as divinely revealed. The doctrine of divine illumination also speaks of a divine initiative, but that initiative is directly cognitive rather than volitional (Pasnau 2015: sect. 1). It holds that divine illumination is required for a number of apparently ordinary cognitive activities, which are engaged in by believers and non-believers alike.