In this volume a few of these lectures, and also some contributions to symposia, have been selected for republication, in the hope that they may provide an introduction to ideas that are set out systematically and with evidence in the three volumes on Attachment and Loss, recently completed. Since each lecture or contribution (referred to here uniformly as lectures) was addressed to a particular audience on a particular occasion, I have thought it better to republish them in their original form rather than attempt any major revision. Each is therefore printed in a form close to that in which it was originally published, with an introductory paragraph describing the occasion and the audience. Opportunity has been taken to correct grammar and to standardize terminology and references; and a few explanatory footnotes have been added, in square brackets, where they seemed
necessary. Whenever a statement calls for modiﬁcation or ampliﬁcation in the light of further evidence or study I have added a comment and given further references (often to chapters in one of the volumes of Attachment and Loss) in an annotation at the end of the lecture. A section has been omitted from Lecture 3 for reasons explained in the text.