 Kant’s Critical philosophy does not distinguish clearly between the rather different streams of natural law that it is usually thought to have surpassed (Hochstrasser 2000, Hartung 1998, Haakonssen 2006). Indeed, when Kant arrived on the scene the two had already been thoroughly commingled, and the discipline as a whole straddled an uncomfortable position between the rational and the empirical. Its situation now became increasingly precarious, as it was subjected to epistemological and metaphysical challenges that it had not been designed to meet, and whose purist, a priori assumptions it would reject (Hunter 2001, 2002, 2005). Like much else, Kant effectively folded natural law into the dialectical pre-history of his own system. In fact, he hardly mentions it at all, since it does not fit the formal schematic of his conception of the history of philosophy as a conflict between dogmatic rationalism and sceptical empiricism. In ethics, natural law is implicitly dismissed in the critique of technical and prudential imperatives, and in political philosophy it appears similarly wanting in the face of pure Right. To be sure, Kant’s own views in both areas – including the notion of categorical obligation, the historical-political mechanism of ’unsocial sociability’, and the trademark concept of ‘autonomy’ mediated by Rousseau’s General Will – owed significant debts to Pufendorf and the voluntarist tradition (Schneewind 1993, 2009, 2010; Kersting 2006). However, since his system gave that problematic a new (in)significance, it did not play an explicit role in his discussions. Kant’s sole mention of Pufendorf (in the company of Grotius and Vattel) is a vague and dismissive reference to the “wretched comforters” (leidige Tröster) who are criticized – in the essay on Perpetual Peace (Zum ewigen Frieden, 1795) – for their overly flexible, empirical, and situational treatment of the law of nations (ius gentium). Ironically, that approach (including sovereigns’ resort to prudence and the right of necessity) had previously been considered a strength, but Kant saw it as little more than a recipe for endless war. In its place, he substituted a universal, necessary, and absolute metaphysics of right – albeit in a transcendental vein – precisely of the sort that the ‘modern’ natural law theory of Hobbes and Pufendorf had originally sought to displace because of its pernicious social consequences. 