When the holders of endowed chairs give inaugural lectures it is common for the lecture to begin with a respectful tribute to the achievements of the distinguished scholars in whose shoes the incumbent now stands. In the case of a personal chair this is obviously not possible. It is appropriate, though, that I should none the less acknowledge here the intellectual debts that I owe to others. But those who might be mentioned are very numerous. And in order to avoid having to draw invidious distinctions and being bound to offend someone, by commission or omission, I will mention only two giants of scholarship who have both had a profound influence upon me. They are both no longer with us but they remain influential in the work of others including myself.