Epistemic Externalism offers one of the most prominent responses to the sceptical challenge. Externalism has commonly been interpreted (not least by externalists themselves) as postulating a crucial asymmetry between the actual world agent and their brain-in-a-vat (BIV) counterpart: while the actual agent is in a position to know she is not envatted, her BIV counterpart is not in a position to know that she is envatted, or in other words only the former is in a position to know whether or not she is envatted.
In this paper, I argue that there is in fact no such asymmetry: assuming epistemic externalism, both the actual world agent and their BIV counterpart are in a position to know whether or not they are envatted. After presenting the main argument, I examine to what extent the argument survives when one accepts additional externalist-friendly commitments (such as semantic externalism), and I conclude by discussing some of the implications of my conclusion to a variety of debates in epistemology.
Jowett Society Organising Committee: Alexander Gilbert, Charlotte Figueroad, Harry Alanen, Jonathan Egid, Kevin Gibbons, Laurenz Casser, Matthew Hewson, Michael Bruckner, Tomi Francis, and Wen Kin San