Legal Positivism Social Source Thesis and Metaphysical Grounding: Employing Metaphysical Grounding based on Metaphysical Laws

Abstract

The core of legal positivism is the so-called social source thesis, which claims that legal facts are determined only by social facts. I examine an interpretation of this thesis that uses metaphysical grounding as an exact relation between legal facts and social facts. I argue that the current interpretation of the social source thesis in terms of metaphysical grounding has significant drawbacks that stem from it being based on the view that metaphysical grounding is a primitive relation. For that reason, the current interpretation is unintelligible and poses problems with explaining the normativity of legal facts. I present two other views on metaphysical grounding: that it holds due to essences of facts and that it holds due to metaphysical laws. I apply the notion that metaphysical grounding holds due to metaphysical laws and argue that in the case of grounding of legal facts in social facts, this metaphysical law is constituted by instrumental rationality. It provides intelligibility to this grounding relation, is able to explain the normative character of legal facts, and is compatible with the general form of explanation.