Spaak argues that legal positivists need to consider the social thesis in light of an important distinction between two levels of legal thinking, namely, the level of the sources of law (existence) and the level of the interpretation and application of law (content), and that they have good reason to restrict the scope of the social thesis to the level of the sources of law. He argues that by restricting the scope of the social thesis in this way, inclusive legal positivists can avoid having to assume that moral judgements can be true in a non-relative way, that exclusive legal positivists can avoid having to say that judges are creating new law instead of applying pre-existing law, if and insofar as they invoke normative considerations in their interpretation and application of the law, and that both inclusive and exclusive legal positivists can avoid Dworkin’s theoretical disagreement objection.

Gizbert-Studnicki considers how we are to understand the social thesis and whether the social thesis, properly understood, can handle Hume’s guillotine, that is, the problem also known as the fact-value gap or the is-ought problem that Hume first articulated in book III, part I, section I of his A Treatise of Human Nature (1739), according to which one may not logically derive an ‘ought’ from an ‘is’. Having distinguished three interpretations of the social thesis – the social sources thesis, the sources thesis and the social fact thesis – he focuses on the social fact thesis, which is a metaphysical thesis according to which legal facts are ultimately determined by social facts alone. Gizbert-Studnicki then considers three different ways of understanding the relation between social facts and legal facts along the lines of the social fact thesis, namely, reduction, supervenience and grounding. He maintains that while all three relations are more or less problematic, the grounding relation is to be preferred, and that adopting the idea of grounding helps us avoid Hume’s guillotine, since grounding is not a matter of entailment but a metaphysical relation that holds between facts.

Green considers a strong version of the semantic thesis, according to which legal statements are descriptive statements solely about social facts. He starts from the foundational thesis of positivism, the social thesis, which has it that the existence and content of the law are ultimately based solely in social facts about a community. But he notes that there are two versions of this thesis. Under the reduction version, a legal system and its laws consist of social facts. Under the assignment version, they are not social entities at all; they are norms, understood as abstract objects. But the grounds for assigning these abstract objects to a community are ultimately solely social facts. Focusing on the assignment version, he asks whether the semantic thesis follows from the social thesis, and, if that answer is no, the extent to which legal statements actually conform to the semantic thesis. He argues that assignment positivists can conclude that the answer is negative because, for them, legal statements describe abstract objects. For Green, this simple account of the semantics of legal statements is superior to expressivist accounts and to Raz’s account.