Abstract
Why should a thought experiment, an experiment that only exists in people's minds, alter our fundamental beliefs about reality? After all, isn't reasoning from the imaginary to the real a sign of psychosis? A historical survey of how thought experiments have shaped our physical laws might lead one to believe that it's not the case that the laws of physics lie - it's that they don't even pretend to tell the truth. My aim in this paper is to defend an account of thought experiments that fits smoothly into our understanding of the historical trajectory of actual thought experiments and that explains how any rational person could allow an imagined, unrealized (or unrealizable) situation to change their conception of the universe.