Could you be a brain in a vat, with all your experiences of people, plants, pebbles, planets and more being generated solely by computer inputs? It might seem difficult to know that you aren’t, since everything in the world would still appear just as it is. In his 1981 book, Reason, Truth, and History, Hilary Putnam argues that if you were in such a predicament, your statement ‘I am a brain in a vat’’, would be false since, as an envatted brain, your word ‘vat’ would refer to the vats you encounter in your experienced reality, and in your experienced reality, you are not in one of those but are instead a full-bodied human being with head, torso, arms, and legs living in the wide open world. The following extended thought experiment is intended to illustrate that, contrary to Putnam’s view, you, as an envatted brain, could truthfully believe that you are a brain in a vat.
