This article examines the grappling of modern positivists with the question of legal unity. It presents and contrasts two antagonistic positivist strands—naturalist and normativist—epitomized in the works of Austin and Kelsen, respectively. The two strands correspond to two contrasting models of legal authority—criterial and coherence-based—and they accordingly diverge on the proper explanation of unity. Naturalist, criterial models purport to explain the unity of law based on extra-legal facts alone; normativist, coherence-based models resort strictly to the interrelation of legal elements themselves. Against this backdrop, the article argues that Raz’s work on the subject is torn between Austin and Kelsen: While his naturalist ancestors accounted for legal unity externally, Raz’s prominent works are captivated by the Kelsenian realization that the unity of law must be accounted for internally. Two central upshots follow. First, the analysis provides a litmus test for the (in)ability of naturalist positivism to explain legal unity. Second, Raz’s strategic reliance on Kelsen distorts his work: Both the Grundnorm and validity chains are upended to fit Raz’s naturalist commitments.