  Some theories have adopted certain main tenets of natural law theory, and professed to be natural law theories, but have asserted that even the most unjust laws create an obligation to obey which is both legal and moral. Kant’s (see Alexy 2002, 117–121) is such a theory: a legal system can consist entirely of positive law but must be “preceded by a natural law that establishe[s] the legislator’s authority…to bind others simply by his arbitrary action.” But this purported natural-law basic norm looks not to the justice of the content of the posited legal rules, but exclusively to the need for legal certainty and civic peace, which Kant takes to exclude any right to resist unjust laws and any denial that they are fully legal. Alexy has pointed out the confusions and inconsistencies in Kant’s attempts to evade the classic position that laws whose injustice is sufficiently grave can and should be denied to have the legal character predicable of laws that citizens and courts, precisely as courts, are morally and juridically entitled to treat as—or as if they are—not law. In this as in many other respects, seventeenth and eighteenth century philosophical developments (like their twentieth and twenty-first century counterparts) were not so much progress as regress. But precisely how the classic position itself should be formulated, explained and applied today is debated between Alexy, Finnis and others (Alexy 2013; Finnis 2014; Crowe 2019).