This chapter further situates my Kantian account of thought experiments among competing views. I identify problems for contemporary accounts and contrast epistemological questions (How do thought experiments justify?), which guide most of the current scholarship, with Kant’s emphasis on cognition [Erkenntnis] (What makes concepts meaningful?). I note that metaphilosophical questions on the relationship between conceivability and possibility are not relevant for thought experiments if they are an apparatus for cognition, which is neutral toward the truth or actuality of the objects of cognition. Contemporary accounts that begin with Kuhn’s epistemological question differ on what the basis of knowledge might be. Leading approaches appeal to logic, stored knowledge, and intellectual intuition. I will briefly sketch here some of the basic approaches.