Brains in a Vat

The "Brain in a Vat" is a thought experiment in epistemology that challenges our certainty about the external world. It posits that you could be merely a brain, kept alive in a vat and fed simulated sensory experiences by a supercomputer.

This scenario highlights the problem of skepticism, suggesting that it's logically possible for our sense experiences to be entirely fabricated. Even if our experiences seem real, the thought experiment implies a gap between these experiences and the actual existence of an external reality. Therefore, claims to know anything about the external world can be questioned, as a mistake is always logically possible.1