Here, I will continue the attack against this answer to our question, but I will also point out a limited way in which this approach may have some merit. Author Information. Uses[ edit ] The simplest use of brain-in-a-vat scenarios is as an argument for philosophical skepticism  and solipsism.
Many writers have found Putnam's proposed solution unsatisfying, as it appears to depend on irrelevant facts about meaning: regardless of whether we can express it, there seems to be a real problem of knowledge here. That, it at least seems, would provide the boldest, strongest, and most definitive possible response to the pointed question.
Australasian Journal of Philosophy Brains in a Vat and Self-Knowledge Ted Warfield has sought to provide an argument that we are not brains in a vat based on considerations of self-knowledge.
This is often referred to as the account from externalism or ultra-externalism. But the problem is that we cannot beg the question by assuming we are speaking in English: if we assume that, then we know in advance of any argument that we are not speaking in Vatese and hence that we are not brains in a vat.
This of course makes our definition of "real" even more muddled.