Legal positivism is generally characterized by its commitment to two theses —one negative, the other positive.See, e.g., Jules Coleman, Negative and Positive Positivism, J. LEGAL STUD. 139 (1982), reprinted in Jules L. Coleman, MARKETS, MORALS AND THE LAW 3 (1988). The negative thesis, usually referred to as the “Separability Thesis,” denies any necessary connection between morality and legality. Legal positivists do not require that a norm possess any desirable, or lack any undesirable, moral attributes in order to count as law.

No one denies that moral principles figure in legal argument and practice. However, the kind of role morality can or must play in law has been a topic of debate not only between positivists and their critics, but also within the positivist camp. The topic was brought into contemporary prominence by Ronald Dworkin, who in The Model of Rules I made the provocative observation that the legality of norms appears to depend sometimes on their substantive (moral) merits, and not just on their pedigree or social source.Ronald Dworkin, The Model of Rules I, in TAKING RIGHTS SERIOUSLY 14 (1977). The observation was intended by Dworkin as a challenge to the positivism of H.L.A. Hart.

A familiar jurisprudential view is that a judicial decision functions as a legal precedent by laying down a rule and that the content of this rule is set by officials. Precedents can be followed only by acting in accordance with this rule. This view is mistaken on all counts. A judicial decision functions as a precedent by being an example. At its best, it is an example both for officials and for a target population. Even precedents outside of law function as examples when they have conduct-guiding significance. Examples may be rule-like in their scope, but need not be. Their import is independent of their justification; this point has implications for coherence theories of precedent meaning. The content and scope of a legal decision’s extension is not set exclusively by officials. It is socially set and depends upon social salience.