Abstract

This paper evaluates Putnam’s argument in the first chapter of Reason, Truth and History, for the claim that we can know that we are not brains in a vat (of a certain sort). A widespread response to Putnam’s argument has been that if it were successful not only the world but the meanings of our words (and consequently our thoughts) would be beyond the pale of knowledge, because a causal theory of reference is not compatible with our having knowledge of the meanings of our words. I argue that this is not so. I argue also, however, that given how Putnam argues (here) for the causal theory of reference, he cannot after all escape this consequence.