Perception as Evidence: Cognitive Penetration and Justification

Perceptual experience is commonly regarded as a basic source of evidence because it appears to provide direct, theory-neutral access to the world. On this standard view, its epistemic authority derives from its independence from higher-level cognition, allowing perception to test rather than merely reflect prior beliefs. Gary Lupyan (2017) challenges this framework by arguing that perception is systematically influenced by top-down cognitive processes and is therefore cognitively penetrated. If perceptual experience is shaped by prior beliefs, it may no longer function as an independent source of justification, raising concerns about epistemic circularity. In this paper, I critically assess Lupyan’s argument and its implications for perceptual justification. While I accept his empirical claim that perception is influenced by cognition, particularly in cases involving visual illusion, I argue that he overstates the epistemic threat. Cognitive penetration, by itself, does not undermine perception’s role as a basic source of justification. I contend that Lupyan’s argument relies on an overly demanding conception of perceptual justification, one that fails to account for the roles of reliability, defeasibility, and the clarity of experience in determining justificatory status. Drawing on evidentialist reliabilism and critiques of quasi-inferential models, I argue that perceptual justification does not require theory-neutrality. A cognitively penetrated perceptual system can still provide genuine justification, and in some cases may be more reliable than a cognitively unmediated alternative. This account preserves a non-skeptical but non-naïve understanding of perceptual justification.