 Arguably the most serious challenge to modularity at the level of input systems, however, comes from evidence that vision is cognitively penetrable, and hence, not informationally encapsulated. The concept of cognitive penetrability, originally introduced by Pylyshyn (1984), has been characterized in a variety of non-equivalent ways (Stokes, 2013), but the core idea is this: A perceptual system is cognitively penetrable if and only if its operations are directly causally sensitive to the agent’s beliefs, desires, intentions, or other nonperceptual states. Behavioral studies purporting to show that vision is cognitively penetrable date back to the early days of New Look psychology (Bruner and Goodman, 1947) and continue to the present day, with renewed interest in the topic emerging in the early 2000s (Firestone &amp; Scholl, 2016). It appears, for example, that vision is influenced by an agent’s motivational states, with experimental subjects reporting that desirable objects look closer (Balcetis &amp; Dunning, 2010) and ambiguous figures look like the interpretation associated with a more rewarding outcome (Balcetis &amp; Dunning, 2006). In addition, vision seems to be influenced by subjects’ beliefs, with racial categorization affecting reports of the perceived skin tone of faces even when the stimuli are equiluminant (Levin &amp; Banaji, 2006), and categorization of objects affecting reports of the perceived color of grayscale images of those objects (Hansen et al., 2006). 