brain in a vat

A brain in a vat that believes it is walking

In philosophy, the brain in a vat is an element used in a variety of thought experiments intended to draw out certain features of our ideas of knowledge, reality, truth, mind, and meaning. It is based on an idea, common to many science fiction stories, that a mad scientist, machine, or other entity might remove a person's brain from the body, suspend it in a vat of life-sustaining liquid, and connect its neurons by wires to a supercomputer which would provide it with electrical impulses identical to those the brain normally receives. According to such stories, the computer would then be simulating reality (including appropriate responses to the brain's own output) and the person with the "disembodied" brain would continue to have perfectly normal conscious experiences without these being related to objects or events in the real world.

The simplest use of brain-in-a-vat scenarios is as an argument for philosophical skepticism and solipsism. A simple version of this runs as follows: Since the brain in a vat gives and receives exactly the same impulses as it would if it were in a skull, and since these are its only way of interacting with its environment, then it is not possible to tell, from the perspective of that brain, whether it is in a skull or a vat. Yet in the first case most of the person's beliefs may be true (if they believe, say, that they are walking down the street, or eating ice-cream); in the latter case their beliefs are false. Since the argument says one cannot know whether one is a brain in a vat, then one cannot know whether most of one's beliefs might be completely false. Since, in principle, it is impossible to rule out oneself being a brain in a vat, there cannot be good grounds for believing any of the things one believes; a skeptical argument would contend that one certainly cannot know them, raising issues with the definition of knowledge.

The brain in a vat is a contemporary version of the argument given in Hindu Maya illusion, Plato's Allegory of the Cave, Zhuangzi's "Zhuangzi dreamed he was a butterfly", and the evil demon in René Descartes' Meditations on First Philosophy.

Cultural references

The brain as a thought and consciousness producing chemical system. Brains rely on action potentials to bring information from the sense organs.^[1]

• The Whisperer in Darkness
• The Brain of Morbius
• City of Lost Children
• Cold Lazarus
• Dark Star
• Donovan's Brain
• Futurama
• Gangers in Doctor Who
• Inception
• The Man with Two Brains
• The Matrix film series
• Possible Worlds
• Psycho-Pass
• Repo Men
• Sid Meier's Alpha Centauri
• Source Code
• "Spock's Brain"
• Strange Days
• The Thirteenth Floor
• "The Vacation Goo", a third season episode of American Dad!
• Ship in a Bottle, an episode of Star Trek: The Next Generation

See also

• Dream argument
• Evil demon
• Experience machine
• Externalism
• Internalism and externalism
• Neurally controlled animat
• Simulated reality
• Skeptical hypothesis
• Solipsism
• Technological singularity

References

External links

Philosophy

• Skepticism and Content Externalism entry by Tony Brueckner in the Stanford Encyclopedia of Philosophy
• Brain in a vat entry in the Internet Encyclopedia of Philosophy
• Putnam's discussion of the "brain in a vat" in chapter one of Reason, Truth, and History. Cambridge: Cambridge University Press. 1981. p. 222. ISBN 0-521-29776-1; ISBN 978-05-2129-776-9.
• 'Where Am I?' by Daniel Dennett
• "Brain in a Vat Brain Teaser" – Harper's Magazine (1996)

Science

• Adaptive flight control with living neuronal networks on microelectrode arrays
• Architecture for Neuronal Cell Control of a Mobile Robot