"War carries the minds as well as the bodies of men into strange paths, and so creates an unwonted need for self-understanding. At the same time, the power and the leisure for self-understanding are diminished. Men, as well as nations, must choose their part quickly, discern their friends and their enemies, revise all plans, leap to strange tasks at the call of the moment, though all the questions of politics and of metaphysics are involved in the deed. And while the decision reached may reveal the solvency or insolvency of the soul that issues it, the need to bring together the fragments of one's mental life remains, and will remain for long after the war is past. This book is an attempt to help--the soldier first, and also the civilian--in this task of understanding one's own mind, under the special stresses of war. There must be many such attempts, from different angles of experience: one can only contribute from his own angle, that of the student of human nature and of philosophy, aided by certain special opportunities which the author owes to the courtesy of the Foreign Offices of Great Britain and France"--Preface (p. vii).