In the current literature, discussions of cognitive penetrability focus largely either on interpreting empirical evidence in ways that is relevant to the question of modularity :343–391, 1999; Wu Philos Stud 165:647–669, 2012; Macpherson Philos Phenomenol Res, 84:24–62, 2012) or in offering epistemological considerations regarding which properties are represented in perception :519–540, 2009, Noûs 46:201–222, 2011; Prinz Perceptual experience, Oxford University Press, Oxford, pp 434–460, 2006). In contrast to these debates, in this paper, I explore conceptual issues regarding how we ought (...) to understand the “cognitive” side of cognitive penetrability. I argue that it is only on its most narrow construal that a full-fledged defense of cognitive impenetrability has been forwarded. Specifically, I argue that the defenders of modularity have tacitly identified cognitive states with propositional states, and have thus only defended the idea that early perceptual systems are immune to the impacts of propositional knowledge. My aim then is to raise doubts about the identification of cognitive states with propositional ones. In particular, by focusing on skill, I will broaden the conceptual space for a greater number of states to have the potential to impact perceptual processing in a way that would constitute a genuine instance of cognitive penetrability. (shrink)