Properly understood, legal realism stands for the conception of law as a going institution (or set of institutions) distinguished by the difficult accommodation of three constitutive yet irresolvable tensions: between power and reason, science and craft, and tradition and progress.
Realists argue that the availability of multiple, potentially applicable doctrinal sources renders pure doctrinalism a conceptual impossibility. But unlike many of its caricatures, legal realism does not challenge the felt stability of the doctrine at a given time and place. Moreover, this stability, which rests on the convergence of lawyers’ background understandings at a given time and place, is valuable for realists, because it is crucial for complying with the rule of law, namely: the requirement that the law provide effective guidance to its addressees and the prescription that it may not confer on officials the right to exercise unconstrained power. This is why realists find law’s use of categories, concepts, and rules not only unavoidable, but also desirable. Thus, for realists, the doctrinal language of law, which typifies the daily life of the social practice of law, is and should be part and parcel of the legal craft. But because doctrine qua doctrine cannot constrain decision-makers, legal realists insist that some legal actors — notably, legislators and judges of appellate courts — should occasionally use new social developments and new cases as triggers for an ongoing refinement of the law and as opportunities for both revisiting the normative viability of existing doctrines qua doctrines and re-examining the adequacy of the legal categorization that organizes these doctrines.
Given this understanding of the law, it should not be surprising that realists are not puzzled by the continued significance of doctrinal categories in the structure and content of legal discourse. To be sure, legal realism rejects the conventional idea that legal categorization refines some eternal descriptive truths that transcend context and that legal taxonomy aspires to produce a map of mutually exclusive legal categories. Rather, realists insist that the main roles of legal categories are to consolidate people’s expectations and to express law’s ideals with respect to distinct types of human interaction. Therefore, they reconstruct legal taxonomy so as to incorporate their insights on the inherent dynamism of law and the important function of contextual normative analysis in the evolution of legal categories. Recasting legal categorization in these terms recognizes the dynamic dimension of the taxonomic enterprise; it implies that legal taxonomy should be sensitive to context and emphasizes the particular significance of relatively narrow legal categories. Finally, a realist legal taxonomy recognizes and accommodates substantial (although never overwhelming) overlaps among the various legal categories.
Dagan, Hanoch, Doctrinal Categories, Legal Realism, and the Rule of Law (November 8, 2014). University of Pennsylvania Law Review, Vol 163, 2015.