'How we know what would be the case if...' - On the Epistemology of Thought Experiments and Counterfactuals

(Project 3 of the DFG Forschergruppe FOR 1614 'What if? On the meaning, Epistemology, and Scientific Relevance of Counterfactual Claims and Thought Experiments") Although thought experiments are used as a source of justification in many disciplines, and especially in philosophy, they seem to be epistemologically suspicious for at least two reasons: Firstly, it is hard to understand how we could have any kind of knowledge about the non-actual scenarios considered in those experiments; secondly, it seems unclear in the case of many thought experiments what distinguished them from frivolous speculation. In this project, both of these problems will be inquired in a new way by showing that the knowledge which thought experiments can generate can be understood as a special case of the knowledge we can have of the truth of counterfactuals. The reduction of the epistemology of thought experiments to that of the evaluation of counterfactuals will help to explain which cognitive abilities are relevant in evaluating thought experiments, and how our knowledge of the actual world and our ability to simulate non-actual scenarios work together by doing so. The project focusses on thought experiments and counterfactual thinking in those disciplines which are represented in the 'Forschergruppe', i.e. Historiography, Biology, Literary Theory, and most importantly Philosophy.