In On Certainty, Wittgenstein (1969) suggests that our epistemic practices take place within a framework of commitments that work like the hinges on which a door turns. Several authors have tried to incorporate those hinge commitments within a non-liberal account of perceptual justification (Avnur 2012; Coliva 2015, 2022; Wright 2004, 2014). According to this account, perception on its own is insufficient to justify perceptual beliefs. Therefore, perceptual justification has a conjunctive structure, with hinge commitments as an independent conjunct that enables perception to confer epistemic justification on perceptual beliefs. In this talk, I criticize this conjunctive model and sketch an alternative. 

First, I offer a novel reconstruction of the argument that motivates the conjunctive model. In my view, the key step of that argument relies on a principle of underdetermination that, in turn, generates a requirement of independent justification. 

Second, I show that the underdetermination principle has an internalist reading and an externalist reading (Vogel 2014). 

Third, I present a dilemma for defenders of the conjunctive model. If they embrace the internalist reading of the underdetermination principle, dogmatist theories of perceptual justification offer all we need to justify perceptual beliefs. If they adopt the externalist reading, various forms of disjunctivism and reliabilism offer all we need to justify perceptual beliefs. Hence, attempts at incorporating hinges within a conjunctive model are unmotivated.

Fourth, I suggest that liberal accounts of perceptual justification can still introduce hinge-like principles or propositions in their accounts of perceptual justification, provided that they do not construe them as parts of a conjunctive model but of a constitutive account of the epistemic role of perception. Within the constitutive model, there is room for hinge-like propositions that specify environmental conditions for the normal operation of perceptual belief formation, principles that specify psychological laws that govern perceptual belief formation, and entrenched beliefs that serve as presuppositions to address questions in everyday inquiries.