This short paper offers a critique of Joseph Raz’s authority-based argument for what he terms the sources thesis. It is drawn from a section in a draft of Chapter 4 of my DPhil thesis ‘Adjudication and Natural Law’. I have done my best to strip the argument of references to points and conclusions from previous chapters, and it is thus inevitable that certain presuppositions may be relied on in the course of this paper which I do not have space to properly account for here. I will try to note these where they arise and, of course, they can be subjected to critical consideration during the period of questions and discussion.

The paper has three parts. Part I offers a brief word on the theoretical question to which the sources thesis is offered as an answer. Part II presents the sources thesis and considers one of the two main arguments offered for it by Raz. Part III offers a critical analysis of Raz’s second argument for the sources thesis, his argument from the nature of law and, in particular, of law’s claimed authority.