The analysis of both public and private international law presented in this book undermines their usual separation into distinct disciplines, their perceived diffluence into parallel streams. The adoption of an international systemic perspective on private international law instead reveals that this division masks an essential confluence in the two branches of international law.

Private international law was, as explored in Chapter 2, invented and historically conceived as part of an international system of natural law, the law of nations, designed to accommodate pluralism in legal orders. The variety of theories in its early development variously emphasised the importance of territorial or personal connections, but they each had in common a ‘systemic’ conception of private international law as international in both character and function. Chapter 2 also examined the way that in the nineteenth century, under the influence of ideas of international positivism, private international law became reconceptualised as purely autonomous national law – an expression of the ‘sovereignty’ of the state. Modern perspectives on private international law predominantly view it as an aspect of national law reflecting domestic ideas of ‘justice’ and conceptions of private rights, and only equivocally acknowledge its international dimension through the concept of ‘comity’. This approach is an unsatisfactory explanation of private international law, because it fails to acknowledge the implicit adoption of the idea of ‘justice pluralism’, introduced in Chapter 1.