This book is intended simply as a straightforward exposition of the thought of some leading existentialist philosophers: it is not meant to be a critical discussion and evaluation of existentialism as a whole. I hope, however, that it will provide a fuller account than has hitherto been available in English of at least certain aspects of the philosophies concerned.
I have had in view two types of readers: the philosophically minded who have not yet been able to study the thinkers in question, but who would like to have an opportunity of judging the general character of their thought as it is revealed in their major works; and those who look for some kind of help in the frequently arduous task of reading the original texts. That is why I have preferred to devote attention to exposition rather than criticism. The general observations of the introduction and postscript are meant solely for the guidance of those readers who are unfamiliar with the existentialist position.
Finally, I should like to point out that this book is concerned solely with the philosophical work of the authors named and does not take into account their literary output, save when a reference to this part of their work is an indispensable means of clarifying a difficulty in the abstract argument.
I am grateful to Professor Ian W. Alexander and Professor Hywel D. Lewis for their encouragement and advice in the preparation of this volume. I am also indebted to Dr. W. H. Barber for help with the correction of the proofs.