Traditional ideas of war's nobility and heroism were lost as well. I mean, what is heroism when you're just sitting in a trench waiting to be blown up? And after World War I, war might be necessary, but it would never again be glorious. We see this shift in the writing and art that emerged from the Great War, as artists transitioned from Romanticism to Modernism. Think of Hemingway's The Sun Also Rises, which is about a man rendered not noble, but impotent by war. The dark, cruel irony there, that you go to war to become a man, and then war takes away the organ often called your manhood? That defined Hemingway's worldview.