In the autumn of 1980 I was appointed Freud Memorial Visiting Professor of Psychoanalysis at University College, London. In my inaugural lecture I returned to the theme I had spoken on in Canada two years previously. Having always believed that the body of knowledge labelled psychoanalysis should become a part of natural science, I was distressed by the pressure of the opposition. To accept that psychoanalysis should abandon its aim of becoming a natural science and instead should regard itself as a hermeneutic discipline has seemed to me to be not only a result of obsolete ideas about science but also a counsel of despair; because, in a hermeneutic discipline, there are no criteria by the application of which it is ever possible to resolve disagreement.