The article presents the inadequacies of the criminal law studies positivism to apply the substantive unlawful, and introduces the neo-Kantian proposition of supralegal exclusion causes as a way of resolving the gaps and antinomies of the legal system. Employing the Weberian perspective of the substantive rationality, the study seeks to demonstrate two distinct movements in theory of crime: the autocratic perversion of criminal guarantees and the democratic expansion of spaces of freedom. Thus, it classifies two forms of substantive rationality in theory of crime (emancipatory and authoritarian goaloriented rationalities), and identifies supralegal exclusion causes, through the perspective of a critical theory of crime, as one of the possible tools to reduce harm caused by the punitive reasoning.