In philosophy of science, Mach’s account of thought experiments is more often described as relevant for contemporary usage than Ørsted’s. In this chapter, I survey recent Kantian accounts of thought experiment, arguing that the leading views inspired by Kant in philosophy of science remain broadly empiricist. This tendency may be due to their focus primarily on the role of thought experiments in the sciences. In later chapters, I will argue – against recent Kantian views – that Kant understood cognition more broadly to include not only sensory perception but also mathematical construction. Acknowledging that cognition does not always require empirical fulfillment opens new ways of understanding how thought experiments work in philosophy, which may rightly differ from their use in the sciences.