Editing Thought experiment (section)

==Fields==
Thought experiments have been used in a variety of fields, including philosophy, law, [[physics]], and mathematics. In philosophy they have been used at least since [[classical antiquity]], some pre-dating [[Socrates]]. In law, they were well known to [[Roman law]]yers quoted in the [[Pandects|Digest]].<ref>''Catholic Encyclopedia (1913)/Pandects'' "every logical rule of law is capable of illumination from the law of the Pandects."</ref> In physics and other sciences, notable thought experiments date from the 19th and, especially, the 20th century; but examples can be found at least as early as [[Galileo Galilei|Galileo]].

===Philosophy===
In philosophy, a thought experiment typically presents an imagined scenario with the intention of eliciting an intuitive or reasoned response about the way things are in the thought experiment.  (Philosophers might also supplement their thought experiments with theoretical reasoning designed to support the desired intuitive response.)  The scenario will typically be designed to target a particular philosophical notion, such as morality, or the nature of the mind or linguistic reference.  The response to the imagined scenario is supposed to tell us about the nature of that notion in any scenario, real or imagined.

For example, a thought experiment might present a situation in which an agent intentionally kills an innocent for the benefit of others.  Here, the relevant question is not whether the action is moral or not, but more broadly whether a moral theory is correct that says morality is determined solely by an action's consequences (See [[Consequentialism]]).  [[John Searle]] imagines a man in a locked room who receives written sentences in Chinese, and returns written sentences in Chinese, according to a sophisticated instruction manual.  Here, the relevant question is not whether or not the man understands Chinese, but more broadly, whether a [[functionalism (philosophy of mind)|functionalist theory of mind]] is correct.

It is generally hoped that there is universal agreement about the intuitions that a thought experiment elicits.  (Hence, in assessing their own thought experiments, philosophers may appeal to "what we should say," or some such locution.)  A successful thought experiment will be one in which intuitions about it are widely shared.  But often, philosophers differ in their intuitions about the scenario.

Other philosophical uses of imagined scenarios arguably are thought experiments also.  In one use of scenarios, philosophers might imagine persons in a particular situation (maybe ourselves), and ask what they would do.

For example, in the [[veil of ignorance]], [[John Rawls]] asks us to imagine a group of persons in a situation where they know nothing about themselves, and are charged with devising a social or political organization. The use of the [[state of nature]] to imagine the origins of government, as by [[Hobbes|Thomas Hobbes]] and [[John Locke]], may also be considered a thought experiment. [[Søren Kierkegaard]] explored the possible ethical and religious implications of [[Abraham]]'s [[binding of Isaac]] in ''[[Fear and Trembling]]''. Similarly, [[Friedrich Nietzsche]], in ''[[On the Genealogy of Morals]]'', speculated about the historical development of Judeo-Christian morality, with the intent of questioning its legitimacy.

An early written thought experiment was [[Plato]]'s [[allegory of the cave]].<ref>Plato. ''Rep.'' vii, I–III, 514–518B.</ref> Another historic thought experiment was [[Avicenna]]'s "[[Avicennism#Thought experiments on self-consciousness|Floating Man]]" thought experiment in the 11th century. He asked his readers to imagine themselves suspended in the air isolated from all [[Wikt:sensation|sensations]] in order to demonstrate human [[self-awareness]] and [[self-consciousness]], and the [[Substance theory|substantiality]] of the [[Soul (spirit)|soul]].<ref>[[Hossein Nasr|Seyyed Hossein Nasr]] and [[Oliver Leaman]] (1996), ''History of Islamic Philosophy'', p. 315, [[Routledge]], {{ISBN|0-415-13159-6}}.</ref>

===Science===
Scientists tend to use thought experiments as imaginary, "proxy" experiments prior to a real, "physical" experiment ([[Ernst Mach]] always argued that these '''''gedankenexperiments''''' were "a necessary precondition for physical experiment"). In these cases, the result of the "proxy" experiment will often be so clear that there will be no need to conduct a physical experiment at all.

Scientists also use thought experiments when particular physical experiments are impossible to conduct ([[Carl Gustav Hempel]] labeled these sorts of experiment "''theoretical experiments-in-imagination''"), such as [[Einstein's thought experiments|Einstein's thought experiment]] of chasing a light beam, leading to [[special relativity]].  This is a unique use of a scientific thought experiment, in that it was never carried out, but led to a successful theory, proven by other empirical means.