In this book I have written about some aspects of the war which, I believe, the world must know and remember, not only as a memorial of men's courage in tragic years, but as a warning of what will happen again--surely--if a heritage of evil and of folly is not cut out of the hearts of peoples. Here it is the reality of modern warfare not only as it appears to British soldiers, of whom I can tell, but to soldiers on all the fronts where conditions were the same...

The purpose of this book is to get deeper into the truth of this war and of all war--not by a more detailed narrative of events, but rather as the truth was revealed to the minds of men, in many aspects, out of their experience; and by a plain statement of realities, however painful, to add something to the world's knowledge out of which men of good-will may try to shape some new system of relationship between one people and another, some new code of international morality, preventing or at least postponing another massacre of youth like that five years' sacrifice of boys of which I was a witness.
- Summary by Philip Gibbs, from the Preface