What is reality? “The Brain in a Vat” Hypothesis

The Brain in a Vat hypothesis is one of the better known “thought experiments” where someone (usually a philosopher, scientist or student of noetics) thinks up a situation, experiment or hypothesis, to illustrate a conundrum, moral dilemma or illustrate a theory. It is said that Einstein’s Theory of Relativity was based on a thought he had when he was 16 years old. He wondered that if he shone a beam of light into space, and then was able to fly and catch up with that beam and look sidewards at it, travelling at the same speed, what would he see? Would the light appear stationary?

With more than a nod to some Gothic horror story, the “brain in a vat” imagines that a demented scientist has successfully removed a human brain from its body. The brain is then placed in a vat of nourishing liquid that keeps it functioning and to all intents and purposes “alive”. Out spaced-out scientist then attached electrodes to key areas of the brain, and connects these to a sophisticated computer that generates images, sensations and emotions taken from the real world. The brain then receives these electrical impulses which simulate in every detail everyday experiences. In other words the brain receives all the information it would receive through sight, smell, touch etc as if it was back in its a body. The question is, would the brain be able to know that what it was experiencing was not reality, but a simulation? Would that simulation be, in effect reality?

At its heart, the exercise asks you to question the nature of experience, and to consider what it really means to be human. Do you need a body to be human? Even the famous philosopher Descartes questioned whether he could ever truly prove that all his sensations were really his own, and not just an illusion caused by as he put it an “evil daemon.” Descartes concluded “cogito ergo sum” (“I think therefore I am”).  However, the brain in the vat thinks, and therefore exists.

Now you know where the idea for the film The Matrix originated!