Abstract

This article defends a non-positivist theory of law, that is, a theory that accepts the necessary connection between legal validity and moral correctness by reference to the work of John Finnis. It begins with the dual nature of law as comprising both a real or factual dimension and an ideal dimension. Important examples show that at least some kinds of moral defect can deprive law of validity from the perspective of a participant in the legal system. The nature of the connection between moral defectiveness and legal defectiveness is specified in terms of three possibilities: exclusive non-positivism, in which all cases of moral defect render law invalid; inclusive non-positivism, in which moral defect renders law invalid in some cases; and super-inclusive non-positivism, in which legal validity is not affected by moral defect at all. The paper argues for inclusive non-positivism as exemplified by the Radbruch Formula, according to which extreme injustice is not law, and which strikes the right balance between the ideal and real dimensions of law, against John Finnis’s account, which can be seen as an example of super-inclusive non-positivism, although his most recent work has tended towards the inclusive version.