Positivism is one of those words that triggers passionate and often contradictory responses. For some, positivism is a pejorative. Lon Fuller, perhaps more than anyone, charged that positivism was confused about the nature of law, blind to law's inherent morality, and morally corrupting to boot. He even suggested, in different ways, that positivism helped promote the rise of fascism in Europe. Others, in contrast, have treated positivism as a modest and undeniable truth about law. Law, they argued, is morally fallible, and accordingly, the existence and validity of law is a matter of social fact rather than moral necessity. H.L.A. Hart, in particular, offered this perspective. Building on the arguments of Austin and Bentham, his British predecessors, he characterized positivism in ways that took it less as a theory of law by itself than as a starting point for developing a satisfactory theory. Attributing to positivism anything more substantial than this, Hart suggested, would risk both misperceptions about law's nature and also confusions about our political and legal obligations. In terms that are important for appreciating Anthony Sebok's enterprise, those who have followed Hart's lead take positivism to offer only a "thin" theory. That is, positivism involves little more than the apparently simple claim that there is no necessary or logical connection between law and morality. This claim, now standardly called the separability thesis, does not by itself entail any particular position about the nature of law or about the nature of judicial decisionmaking. Theories about those topics need to be developed, on this approach to positivism, in order to complete our understanding of the nature of law; the separability thesis means only that it cannot be a precondition for the adequacy of such theories that law, or legal rules, must always be moral. Fuller's denigration of positivism, on the other hand, assumed that positivism is a "thick" theory, entailing deep but profoundly mistaken views about the nature of law and adjudication and the fundamental morality of both. This thick theory of positivism should be rejected, Fuller maintained, because its concomiiant positions on the nature of law and adjudication are both wrong and pernicious.
Vincent A. Wellman,
Positivism, Emergent and Triumphant,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol97/iss6/23