Descartes struggled with a problem that is now called “the problem of knowing,” and sometimes referred to as the “brain in a vat” dilemma. The idea is that the brain is easy to fool. The only way a person knows what he experiences of reality is the truth is by trusting in the sensory inputs of his own brain. The answer Descartes came up with for this dilemma was, “I think, therefore I am,” which means that thinking is the one thing he knew could not be artificed. Even if thinking comes from a different place than what is expected, the thoughts still come from the individual and define the individual as real, regardless of any other
