There are few areas of law that generate as much controversy and disagreement as family law. It’s something potentially that affects us all, in which we all feel we have a stake and of which some of us have had direct experience. Indeed, there are probably few areas of law that affect so many people so directly in their every day lives. Yet it is probably also true that nowhere is the authority or legitimacy of law more often called into question. Against this rather unpromising background for a public lecture on the topic, I want to do two things this evening. First, I want to suggest that there is a pervasive uncertainty about what family law is for, how it is to set about its primary tasks, and how, if at all, family law should embody conventional notions of legality: and I will suggest that these uncertainties have led to tensions that find expression in contemporary family law. I will also suggest that these uncertainties and tensions have intensified in the last ten years, and I will try and explain how and why this has happened. In short, I will try to provide a map of what has become a confused and tangled terrain of conflicting ideas and tendencies. In doing so, I have tried to develop a conceptual vocabulary that is adequate to that task of description. My second task is probably more controversial, and at the same time probably more important – because I want to offer a defence of the role of law in family matters. I use the word ‘defence’ deliberately, because the role of law, and the institutions of law (such as the Family Court and legal practitioners), has come under sustained attack in recent times. It is suggested that family disputes are only exacerbated by law’s involvement, and that the legal system consistently fails to deliver ‘justice’ to the parties who pass through it. These arguments are heard more and more frequently, and I suspect that they have yet to reach the peak of their intensity. Yet it is not often that one hears the case in reply – the case, that is, for law, and for the values of procedural fairness and legality, that go with it. I do not pretend to have marshalled all the arguments that could be made on this (and I don’t have much to say, because my ideas on this are still not as developed as they I would like) – but I do want to suggest that in areas of radical disagreement, such as the terms on which families should separate, law (at least as a mode of reasoning and as a way of framing practical solutions to disagreement) is perhaps our only hope of finding common ground.