According to the Webster's New World College Dictionary, alienation is 1. Separation, aversion, aberration. 2. Estrangement or detachment. 3. Mental derangement; insanity.
The theme of All Quiet on the Western Front is about how World War I destroyed a generation of young men. It has taken from them the last of their childhood years, it has destroyed their faith in their elders, it has taught them an individual life is meaningless--and all it has given in return is the ability to appreciate basic physical pleasures. According to Paul, though, the men haven't entirely lost human sensitivity: they're not as callous as they appeared in Chapter 1, wolfing down their dead companions' rations. It's just that they must pretend to forget the dead; otherwise they would go mad. Remarque includes discussions among Paul's group, and Paul's own thoughts while he observes Russian prisoners of war (Chapters 3, 8, 9) to show that no ordinary people benefit from a war. No matter what side a man is on, he is killing other men just like himself, people with whom he might even be friends at another time.
But Remarque doesn't just tell us war is horrible. He also shows us that war is terrible beyond anything we could imagine. All our senses are assaulted: we see newly dead soldiers and long-dead corpses tossed up together in a cemetery (Chapter 4); we hear the unearthly screaming of the wounded horses (Chapter 4); we see and smell three layers of bodies, swelling up and belching gases, dumped into a huge shell hole (Chapter 6); and we can almost touch the naked bodies hanging in trees and the limbs lying around the battlefield (Chapter 9).
The crying of the horses is especially terrible. Horses have nothing to do with making war. Their bodies gleam beautifully as they parade along--until the shells strike them. To Paul, their dying cries represent all of nature accusing Man, the great...