Brain in a vatIn philosophy, the brain in a vat (BIV) is a scenario used in a variety of thought experiments intended to draw out certain features of human conceptions of knowledge, reality, truth, mind, consciousness, and meaning. It is a modernized version of René Descartes's evil demon thought experiment, originated by Gilbert Harman. Found in many science fiction stories, it outlines a scenario in which 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 that would provide it with electrical impulses identical to those a brain normally receives.
Dream argumentThe dream argument is the postulation that the act of dreaming provides preliminary evidence that the senses we trust to distinguish reality from illusion should not be fully trusted, and therefore, any state that is dependent on our senses should at the very least be carefully examined and rigorously tested to determine whether it is in fact reality. While dreaming, one does not normally realize one is dreaming. On more rare occasions, the dream may be contained inside another dream with the very act of realizing that one is dreaming, itself, being only a dream that one is not aware of having.
Simulation hypothesisThe simulation hypothesis proposes that all of existence is a simulated reality, such as a computer simulation. This simulation could contain conscious minds that may or may not know that they live inside a simulation. This is quite different from the current, technologically achievable concept of virtual reality, which is easily distinguished from the experience of actuality. Simulated reality, by contrast, would be hard or impossible to separate from "true" reality.
Cartesian doubtCartesian doubt is a form of methodological skepticism associated with the writings and methodology of René Descartes (March 31, 1596Feb 11, 1650). Cartesian doubt is also known as Cartesian skepticism, methodic doubt, methodological skepticism, universal doubt, systematic doubt, or hyperbolic doubt. Cartesian doubt is a systematic process of being skeptical about (or doubting) the truth of one's beliefs, which has become a characteristic method in philosophy.
Meditations on First PhilosophyMeditations on First Philosophy, in which the existence of God and the immortality of the soul are demonstrated (Meditationes de Prima Philosophia, in qua Dei existentia et animæ immortalitas demonstratur) is a philosophical treatise by René Descartes first published in Latin in 1641. The French translation (by the Duke of Luynes with Descartes' supervision) was published in 1647 as Méditations Métaphysiques. The title may contain a misreading by the printer, mistaking animae immortalitas for animae immaterialitas, as suspected by A.
