My original brief for this session was to outline the history of Chancery and equity in English jurisprudence, a task I have performed often enough in the past in the Cambridge schools. As further instructions arrived by fax from Indiana, I began to realise that I was not going to be able to give my usual undergraduate lecture. I was instructed amongst other things to touch on the power of English courts to enjoin public officials and agencies to carry out their duties – such as running schools and prisons – in a way more acceptable to the judges of the day. Since I am aware of the landmark American cases Brown v. Board of Education of Topeka, and Missouri v. Jenkins, I can guess at the reason why I have been asked to talk about the history of equity on the same afternoon that you hear a paper from Justice Thomas. But I have to say at the outset that, whereas the connection between equity and public law may be transparently obvious to an American lawyer, it is much less so to an English lawyer, for whom equity still belongs primarily in the Chancery Division. So I shall attempt to address, in outline, why that is so.

The first task which was set me, however, was to comment on the ultimate source of the equitable power in England. Let us take that first. It can only be tackled in a historical rather than a philosophical vein.