Is it possible that at this very moment you are nothing more than a brain in a vat, connected to a very advanced computer program that is capable of simulating, perfectly, experiences of the outside world? If it is a possibility that you are not a real person with hands and feet and a nose, it also seems possible that what you know about the external world is false. In this paper I will attempt to show that there is no way for us to truly know whether or not we are brains in vats. This will be done by evaluating Hilary Putnum’s refutation to the brain-in-a-vat hypothesis set out by the Cartesian sceptic. By showing that Putnum fails to persuade us against the idea that we could be brains in a vat, I wish for the reader and I to consider the idea that perhaps all we can ever truly know is our thoughts. Although this paper leans toward finding refuge under the umbrella of solipsism, it will not go into the details of solipsism as a thesis; I do, however, wish to consider solipsism as a real possibility in future papers.
Imagine that you are a brain in a vat in a world in which the only objects in existence are brains in vats. These brains in vats are connected to supercomputers in a laboratory; these…show more content… The sentence “I am a brain in a vat” has different truth conditions in English and in vat-English, as such the sentence expresses different propositions in the two languages. If I do not know whether I am speaking English or vat-English when I say “I am not a brain in a vat”, then I do not know what proposition is expressed by my utterance. But all this allows me to claim is that “the metalinguistic knowledge that a certain sentence expresses a false proposition, rather than the object-language knowledge that I am not a brain in a vat”. But it is knowledge of the object-language kind which Putnam needs to refute