The threats of scepticism and epistemic relativism are uncoupled in Kant's transcendental idealism, which embraces a radical scepticism, while seeking to provide an absolute justification for the methods of the exact sciences. After this position was definitively undermined by developments within the exact sciences, Carnap's logical positivism and Kuhn's pragmatism took turns replacing it as the dominant philosophies of science of the twentieth century. Interestingly, both of these positions can be understood as endorsing the principal argument for epistemic relativism. This chapter examines these relativistic readings of Carnap and Kuhn, without endorsing them, in an effort to reveal that epistemic relativism is an endogenous threat to analytic philosophy.