This paper is divided into two sections. In the first section I examine the central role played by the concept of ‘legal validity’ in positivist theories of law. I suggest that this concept is capable of varying interpretations, of which some are wholly inapplicable to case law, while others are inappropriate, suggesting a misleading model of case law reasoning.

In the second section, I examine Hart's account of legal validity and the rule of recognition. I suggest that Hart's theory is inadequate because it fails to perceive the special nature of binding practices. I argue that the notion of a binding practice provides the most fruitful basis for an understanding of the common law, and explains the status of case law independently of Hart's account in terms of ‘legal validity’ and the rule of recognition.