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Licensed Unlicensed Requires Authentication Published by De Gruyter August 31, 2016

Additional Reflections on Putnam, Wright and Brains in Vats

Harold W. Noonan
From the journal Metaphysica


Putnam’s argument against the sceptical Brain-in-a-Vat hypothesis continues to intrigue. I argue in what follows that the argument refutes a particular kind of sceptic and make a proposal about its more general significance. To appreciate the soundness of the argument, I explain, we need to appreciate that the sceptic’s contention is that I cannot know that I am not a brain in a vat even if I am not. This is why in response to the sceptic it is legitimate to make a transition from knowing that a sentence is true to knowing the truth it expresses, which is the crucial move in the argument.


Putnam, H. 1981. Reason, Truth and History. Cambridge: Cambridge University Press.10.1017/CBO9780511625398Search in Google Scholar

Wright, C. 1992. “On Putnam’s Proof That We Are Not Brains-in-a-Vat.” Proceedings of the Aristotelian Society LXXXXII:67–94.10.1093/aristotelian/92.1.67Search in Google Scholar

Published Online: 2016-8-31
Published in Print: 2016-9-1

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