The Semantic Thesis in Legal Positivism

Torben Spaak & Patricia Mindus (Eds.), Cambridge Companion to Legal Positivism 536-58 (Cambridge University Press 2021)

26 Pages Posted: 8 Jul 2021 Last revised: 10 Jul 2021

Date Written: July 1, 2021


For positivists, law ultimately depends solely on social facts about a community’s legal practices. This is a metaphysical thesis about the nature of law. But most positivists — including Scott Shapiro, Joseph Raz, and H.L.A. Hart — reject a semantic thesis, according to which statements about the law are solely descriptions of those social facts. The semantic thesis, they argue, is unable to account for those legal statements, commonly using normative language, that Hart calls “internal.”

Some argue that internal legal statements are not (or not solely) descriptions of social facts because they express one’s acceptance of conformity with legal practices. In response to difficulties with this expressivist approach (including the so-called Frege-Geach problem), Raz offers a detailed alternative, according to which they describe moral facts that would exist from the legal point of view, that is, on the assumption that there are always moral reasons for conformity to legal practices. Raz’s approach, although avoiding the Frege-Geach problem, has its own difficulties.

I argue for a much simpler reason for positivists to reject the semantic thesis. Most positivists are assignment positivists, not reduction positivists. Reduction positivists believe that a legal system and its laws are reducible to social facts about a community’s legal practices, the way a traffic jam is reducible to facts about its constituent cars. For assignment positivists, by contrast, a legal system and its laws are abstract objects, not social entities. But these philosophers remain positivist, for they think that the grounds for assigning certain of these objects to a community — such that they are the legal system and laws of that community — are ultimately solely social facts about the community’s legal practices.

Consider the following analogy. Many philosophers consider a language to be an abstract object. The fact that “Le chat est sur le tapis” means that the cat is on the mat in French is not a social fact concerning French linguistic practices but is instead a necessary truth concerning the abstract object that is French. Nevertheless, these philosophers believe that the grounds for assigning that abstract object to the French community are solely social facts about that community. It is a contingent fact that the French speak French rather than, say, Esperanto. That they speak French depends solely upon social facts concerning French linguistic practices.

By analogy, assignment positivists should reject the semantic thesis for the simple reason that internal legal statements describe necessary truths about the abstract objects that are a legal system and its laws. This approach, which was probably the one adopted by Hart himself, overcomes the problems with expressivism — in particular, the Frege-Geach problem — while avoiding the difficulties with Raz’s approach.

Keywords: positivism, expressivism, pragmatics, abstract objects, law and language, philosophy of law, internal legal statements, Frege-Geach problem, H.L.A. Hart, Joseph Raz

Suggested Citation

Green, Michael S., The Semantic Thesis in Legal Positivism (July 1, 2021). Torben Spaak & Patricia Mindus (Eds.), Cambridge Companion to Legal Positivism 536-58 (Cambridge University Press 2021), Available at SSRN: or

Michael S. Green (Contact Author)

William & Mary Law School ( email )

South Henry Street
P.O. Box 8795
Williamsburg, VA 23187-8795
United States
(757) 221-7746 (Phone)

Do you have negative results from your research you’d like to share?

Paper statistics

Abstract Views
PlumX Metrics