An argument could be made that it was the end of the Modern era, which was defined above all by an indelible assurance regarding 'the march of progress'. People at the time related the profound metaphysical impact of the war, especially after it became a war of attrition on a gruesome scale. Its survivors became known as the Lost Generation. The philosophical movement that would become known as Postmodernism began to coalesc in the years following the war.