Thought experiments in philosophy and science have a lot in common. However, this chapter focuses on thought experiments in philosophy only. It provides an overview of the results that discussion has achieved and point out which issues are still open. In metaphilosophy, thought experimentation is also often referred to as "the method of cases"; and there sometimes seems to be an assumption in metaphilosophy that there is a common methodological role that thought experiments play throughout philosophy. The chapter explores that this assumption is mistaken, by pointing out two other methodological roles that thought experiments play in philosophy. However, there is one role which seems to be the most interesting from a metaphilosophical point of view, namely the use of thought experiments as counterexamples or "alethic refuters". The chapter discusses several attempts at reconstructing the logical structure of such refutations by thought experiments. It concludes with a few general remarks about the prospects of metaphilosophy and modal epistemology.