View source for Brain in a Vat

'''Brain in a vat''' is a thought experiment in epistemology and philosophy of mind that asks whether a brain, artificially stimulated to produce identical sensory experiences to those of an embodied human, would have conscious experiences indistinguishable from normal perception. The scenario, often attributed to [[René Descartes|Descartes]]'s evil demon hypothesis and updated by [[Hilary Putnam]] in the 1980s, is designed to test the limits of skepticism and the nature of knowledge: if all your experiences are simulated, how could you know that the external world exists?

The [[Sensorimotor Contingency Theory|sensorimotor contingency theory]] of perception, developed by [[Alva Noë]], challenges the brain in a vat scenario at its root. If perception is not the passive reception of sensory input but the active mastery of sensorimotor laws, then a brain in a vat — which has no body to move and no environment to interact with — would not perceive at all. It would have stimulation, but not perception. The scenario presupposes the very representationalism that the sensorimotor theory rejects: it assumes that if you replicate the inputs, you replicate the experience. But if the experience is in the sensorimotor loop, not in the inputs, then the brain in a vat is not a conscious subject but a stimulated organ in a jar.

[[Category:Philosophy]]
[[Category:Consciousness]]
[[Category:Epistemology]]