APA Dictionary of Psychology

a mental exercise in which a hypothesis or idea is put to the test without actually conducting an experiment or research project. The purpose is to explore the logical consequences of the hypothesis or idea. Thought experiments often involve arguments about events of a hypothetical or counterfactual nature, which nevertheless have implications for the actual world. They can be used to challenge the intellectual status quo, correct misinformation, identify flaws in an argument, or generate ideas as part of a problem-solving exercise. Thought experiments are most familiar in philosophy (e.g., Chinese room argument) but are also used in the physical sciences, generally as a step toward designing a physical experiment.