On my last visit to New Zealand in 1999 I spoke as an outsider to a sceptical audience on how best to interpret the Treaty of Waitangi.1 I said that one of the great challenges facing a country formed by successive waves of immigrants is to put together disparate norms from rival cultures, each of which has its own distinctive legal understandings as to how the world does or should work.

On that occasion I said that I would like to start from a neutral corner, and then proceeded to address several Roman law analogues to the question of prescriptive rights, largely on the basis that the great Roman authors were not influenced by the future events that unfolded in New Zealand. On this occasion, I plan to do likewise in discussing the foreshore and seabed. Rather than trying to deal with this topic from the point of view of English law on the one hand or Maori customary law on the other, I want to locate some kind of tertiam quid - a third point - from which to begin the analysis. So for yet another time I find an unexpected use of my training as a Roman property lawyer, which has long augmented the English property law that I learned as a student at Oxford many years ago. I also begin with the confession that, even after the advent of law and economics, I remain much influenced by the writings of Gaius and Justinian on the creation and organisation of property rights.