This article has two purposes. The first speaks to the compatibilist quality of Charles Mills’ Black Radical Kantianism (BRK), its strengths and weaknesses and the pertinence of W. E. B Du Bois to it. BRK turns from Mills’ previous critique of Kantianism as representative of a rassenstaatlich political liberalism, underwritten and tainted by the racial/domination contract, to his current defence of a compatibilist Kantianism as representative of a rechtsstaatlich political liberalism supported by a non-ideal racially corrective critique of both that contract and the kind of political liberalism affiliated with it. The second focuses on what I introduce as the ‘Radicalization of Kant in Black’ (RKB). RKB is not a compatibilist project. Rather it re-examines issues first posed by ‘slave- and black-encoded’ blacks coming to act and struggle with the primacy of practical reason under the historically normative authority of freedom and the abolition of enslavement. What are the ramifications of each for Kant-/Kantian-radicalization?