I defend the view that there is a privileged class of propositions – that there is an external world, among other such 'hinge propositions'– that possess a special epistemic status: justified belief in these propositions is not defeated unless one has sufficient reason to believe their negation. Two arguments are given for this conclusion. Finally, three proposals are offered as morals of the preceding story: first, our justification for hinge propositions must be understood as defeatable, second, antiskeptics must explain our (...) knowledge in the face of 'actual world' skepticism (like dreaming skepticism) as much as in the face of the usual sort (like brain-in-vat skepticism), and, finally, our justification for hinge propositions is basic (i.e. non-inferential). (shrink)

There are two different kinds of theories of the concept of epistemic defeat. One theory begins with propositional relationships, only by implication describing what happens in the context of a noetic system. Such a theory places inforrmation about defeat up front, not informing us of how the defeat relationships play out in the context of actual belief, at least not initially. The other theory takes a back door to the concept of defeat, assuming a context of actual belief and an (...) entire noetic system, and describing defeat in terms of what sort of doxastic and noetic responses would be appropriate to the addition of particular pieces of information. Where the house is the noetic structure itself, the front door approach characterizes the concept of defeat in terms of the propositional contents a belief might have, thus characterizing defeat at the front door. The backdoor approach characterizes defeat in terms of what leaves the house, in terms of beliefs that exit the noetic system in response to changes to it, in terms of what the staff of a well-run household kicks out the backdoor for making a mess of things. Alvin Plantinga’s theory of epistemic defeat is a back-door theory, and here I will argue that his theory and approaches like it will be unable to explicate accurately the concept of epistemic defeat. I will argue that a front door approach is needed rather than a back door approach. (shrink)