I argue that Quine’s naturalization of Lewis’s Kantian pragmatism should be understood in terms of Lewis’s attempt to de-psychologize pragmatist epistemology. Lewis wants epistemology to be a priori in order to be distinct from psychology. Quine’s criticisms of Lewis result in a picture that weakens the distinction between epistemology and psychology. Nevertheless, Quine’s naturalized Kantian pragmatism remains far more Kantian than is widely recognized, due to what Quine retains from Lewis.