title: The step to rationality: the efficacy of thought experiments in science, ethics, and free will.
abstract: Examples from Archimedes, Galileo, Newton, Einstein, and others suggest that fundamental laws of physics were-or, at least, could have been-discovered by experiments performed not in the physical world but only in the mind. Although problematic for a strict empiricist, the evolutionary emergence in humans of deeply internalized implicit knowledge of abstract principles of transformation and symmetry may have been crucial for humankind's step to rationality-including the discovery of universal principles of mathematics, physics, ethics, and an account of free will that is compatible with determinism.
authors.affiliation: Department of Psychology, Stanford University, and The Arizona Senior Academy.
authors.forename: Roger N
authors.initials: RN
authors.lastname: Shepard