This volume... consists partly of a selection of technical psycho-analytical studies, partly of papers which either touch upon the bearing of psycho-analysis on the upbringing and education of young children, or link their social and emotional life with their intellectual and practical needs. Most of these essays deal with children; in any case they rest upon the relationship between childhood and adult life, as for example "The Modifications of the Ego", where it can be clearly seen that it is not possible to understand the adult without going back to the feelings, phantasies and experiences of the infant. In "The Criteria of Interpretation" there is very little reference to children, the paper being concerned with psycho-analytic work with adults, but the same implications will be seen there also. In the nature of the case some of the essays are more popular than others, but I hope that none of them will be found so technical as to be devoid of interest to those concerned with the psychological problems of little children. Those previously published have not been changed save for a few minor verbal alterations. They are arranged simply in order of publication (or delivery, if previously unpublished). This edition first Published in 1999. Routledge is an imprint of Taylor & Francis, an informa company.