The Queen's College, Oxford, UK In his article `Facts and Principles', G.A. Cohen attempts to refute constructivist approaches to justification by showing that, contrary to what their proponents claim, fundamental normative principles are fact- in sensitive. We argue that Cohen's `fact-insensitivity thesis' does not provide a successful refutation of constructivism because it pertains to an area of meta-ethics which differs from the one tackled by constructivists. While Cohen's thesis concerns the logical structure of normative principles, constructivists ask how normative principles should be justified . In particular, their claim that justified fundamental normative principles are fact-sensitive follows from a commitment to agnosticism about the existence of objective moral facts. We therefore conclude that, in order to refute constructivism, Cohen would have to address questions of justification, and take a stand on those long-standing meta-ethical debates about the ontological status of moral notions (for example, realism versus anti-realism) with respect to which he himself wants to remain agnostic. Key Words: John Rawls normative justification realism versus anti-realism methodological versus substantive principles.