In this paper, I defend the viability and importance of conceptual analysis to philosophical inquiry. My argument proceeds in two steps. In a first step, I argue that we rely on the notions guiding how we do and would apply our terms in order to evaluate the counterfactual conditionals we find at the heart of philosophical thought experiments. In a second step, I argue that our notions determine what the relevant terms mean in our mouth. In order to defend the resulting neo-descriptivist semantics, I put forth an epistemic argument for descriptivism—the argument from communication. I conclude that philosophical thought experiments are exercises in conceptual analysis.