---
title: "Thought experiment"
chunk: 2/3
source: "https://en.wikipedia.org/wiki/Thought_experiment"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:40:49.296499+00:00"
instance: "kb-cron"
---

challenge the prevailing status quo (which includes activities such as correcting misinformation (or misapprehension), identify flaws in the argument(s) presented, to preserve (for the long-term) objectively established fact, and to refute specific assertions that some particular thing is permissible, forbidden, known, believed, possible, or necessary)
extrapolate beyond (or interpolate within) the boundaries of already established fact
predict and forecast the (otherwise) indefinite and unknowable future
explain the past
facilitate the retrodiction, postdiction and hindcasting of the otherwise indefinite and unknowable past
facilitate decision making, choice, and strategy selection
solve problems, and generate ideas;
move current unsolved problems into another more productive problem space (e.g. functional fixedness)
attribute causation, preventability, blame, and responsibility for specific outcomes
assess culpability and compensatory damages in social and legal contexts
ensure the repeat of past success
examine the extent to which past events might have occurred differently
ensure the future avoidance of past failures

== 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 lawyers quoted in the Digest. 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.

=== 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 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 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. Another historic thought experiment was Avicenna's "floating man" thought experiment in the 11th century. He asked his readers to imagine themselves suspended in the air isolated from all sensations in order to demonstrate human self-awareness and self-consciousness, and the substantiality of the soul.

=== 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 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.

== Properties ==
Further categorization of thought experiments can be attributed to specific properties.