Falsehood in War-time identifies the role propaganda played in World War I, in general and specific terms and lists more than 20 falsehoods that were circulated during the First World War. Ponsonby regarded these falsehoods as a fundamental part of the way the war effort was created and sustained, stating that without lies there would be "no reason and no will for war".[4]
In detail, Ponsonby analyses the case of the invasion of Belgium as a cause of the war, the claim of Germany's sole responsibility, the myth of a nurse mutilated by German soldiers, the depiction of the German Emperor as a criminal, the case of a Belgian baby whose hands were cut off, the Leuven altarpiece which had allegedly been destroyed by Germans, the baby of Courbeck Loo, the crucified Canadian soldier, the German Corpse Factory, the German U-boat outrage, the case of the sinking of the Lusitania, atrocity stories reported on German Army troops which were reported killing and maiming of innocent civilians and captured soldiers, faked photographs, the doctoring of official documents, and the "hypocritical" indignation.
As to the Song of the Germans, base for the later German national anthem of the Weimar Republic (since 1922): "Deutschland über Alles auf der ganzen Welt" (Germany above everything in the whole world), Ponsonby said it was popularly accepted as meaning, "[Let] Germany [rule] over every country in the whole world," i.e. the German domination of the world. However, German grammar distinguishes between über Alles (i.e. more important than everything else) and über alle, meaning "on top of everybody."[5] According to Ponsonby, the latter misleading translation was chosen by the Allies during both World Wars for propaganda purposes.
Falsehood in War-Time was positively received on its release. The International Journal of Ethics calls Ponsonby’s work "an interesting study of the moral degradation involved in all wars." In addition, the World Tomorrow welcomed the book as a direct way of describing propaganda in World War One and states it is, "decidedly to the good." One of Ponsonby’s critics, The Times of London, mentioned Ponsonby omitted the Bryce report. However, The Times recognized that Ponsonby’s writing "is a useful warning against undue credulity." The reception of the book in Germany was positive, where the German Foreign Ministry regarded it as the "best and most effective book... against war atrocity lies" and helped get it translated into French and German.[6]
Anne Morelli systematised the essential propaganda techniques of Ponsonby's work in her book Principes élémentaires de propagande de guerre. Morelli explains how these principles not only worked during the First World War, but were also applied in wars into 2001.[7]
In his book The Last Great War: British Society and the First World War, Adrian Gregory criticised what he saw as methodological errors within Falsehood in War-Time. He wrote that, in some instances, Ponsonby incorrectly charged the British press as manufacturing stories that actually derived from various other sources including rumours, urban myths and German propaganda. He concluded, "material from American isolationist sources, the British pacifist press and even from Germany is taken as truth, British official pronouncements and the British press are assumed to be lying. His book is not an inquiry into propaganda; it is propaganda, of the most passionate sort: Exposure may therefore be useful, even when the struggle is over, in order to show up the fraud, hypocrisy and humbug on which all war rests".[10]