Abstract
An extensive literature on thought experiments exists. The authors try to define or at least to characterize ‘what thought experiments are’ or to assimilate them to methods and argument patterns familiar in the natural and social sciences. It is probably fair to say that due to the large number of thought experiments in the history of ideas and rational thinking about the world any simple classification is bound to fail. Their real interest lies in understanding their epistemic functions. Their fascination derives from their paradoxical nature: they are examples of ‘armchair philosophy’, yet seemingly offer the enticing prospect of teaching us new knowledge about the world. Reflecting on their functions in reasoning will help to dissolve this paradox. But in order to identify their functions it will be useful to present a brief summary of the various models of thought experiments, which have been discussed in the literature.