The article considers some ideal categories as foundations of legal reality. Taking into account the diverse potential prerequisites of law, the author focuses on three modifications of the good highlighted by Plato in the dialogue “Philebus”: the beautiful, the proportionate, and the true. The article argues the utility of employing such a concept of analytical philosophy as supervenience, which describes the determinacy of sets of properties in two complex systems, to explain the interplay between these prerequisites and legal phenomena. While traditionally used to describe the dependence of mental phenomena on physical grounds, supervenience also has a methodological relevance within legal science. Three modifications of the good as delineated in “Philebus” and their contributions to the formation of legal institutions are considered. For this purpose, several levels of aesthetics are distinguished, which not only encompass stylistic beauty, but also the substantive content of legal constructs. Special attention is paid to reader-response criticism, which studies the experience of perception of legal institutions by a subject of legal relations. According to this perspective,legal phenomena have to possess aesthetic appeal and justification in order to be accepted by recipients. This is especially important when consolidating constitutional values: the legitimization of fictitious axiological elements creates risks of legal anomie. The article further underscores the significance of the correspondence theory of truth for the ontology of law, justifying the priority of rational cognition of universals over empiricism. To solve research problems, legal-historical, logical, structural-functional, normative, dialectical, prognostic and comparative methods and approaches are used. Based on the findings of the study, the author concludes about the independent ontological status of legal phenomena that have a sign of reality as intelligible elements within the objective mental being of participants in legal relations.
Keywords: legal reality, prerequisites of law, aesthetics, proportionality, truth, supervenience, objective idealism, ontology of law, reader-response criticism, Plato