Brain in A Vat
Assume that a brain could live in a vat of chemicals and, wired by external electrodes, it would have all the normal experiences: childhood, sex, falling in love, parenting, even skiing, or sky diving. It imagines itself a person capable of a full range of activity. It has beliefs: it is a person with a name, say, Harvey Smedlap; it has a family; it enjoys food; it has orgasms; a god created it and protects it. It regards all this evidence as reliable.
Now, a question: how can one differentiate his own beliefs from that of the brain in the vat? How can one say that his evidence is more reliable than that of the brain?
