Heller's use of contradictions are not only there to make the reader chuckle; they are indicative of how the larger system doesn't make any sense. The Colonels and Majors just sit in their offices and sign papers, caring only about their image. Heller has them put rules in place that contradict themselves explicitly, but through them he shows how the real orders from these bureaucrats are just as insane. Though it might make sense for a large group of people to fight a wrong together, Yossarian sees no reason that he himself should be forced to fight and possibly die when there are millions who are willing to do just that in his place. Though this attitude might not be admirable, it does make sense why a soldier would behave in this way.
A character who I don't think I've even mentioned, yet plays a key symbolic role in the story, is an unnamed 107-year-old man that Nately meets in a brothel in Rome. The old man is a ruthless pragmatist, saying that he was the staunchest Nazi when the Germans were in control of Rome and now was fervently pro-American. When Nately tells him that it is better to die on your feet than live on your knees, the man says "it is better to live on your feet than die on your knees." When Nately tells him how wonderful it is to die for one's country, the old man replies, "Englishmen are dying for England, Americans are dying for America, Germans are dying for Germany, Russians are dying for Russia. Surely so many countries aren't worth dying for." When Nately says that anything worth living for is worth dying for, he says,"And anything worth dying for is worth living for." Many people would cringe at this ruthless pragmatism, but Heller makes his point through the fact that the old man is 107--his ideas help you survive, and, if survival is your goal, pragmatism is the way to go. At its root, this book is darkly cynical, but perhaps that is the only appropriate tone for a war book. Heller, through Yossarian, wants patriots to go and fight and die, while everyone else is allowed to survive.
Finally, I want to leave with one more quote from the conversation between the 19 year-old, idealistic Nately, and the old man who has been able to survive for over a century:
"America," he said, "will lose the war. And Italy will win it"
"America is the strongest and most prosperous nation on earth," Nately informed him with lofty fervor and dignity. "And the American fighting man is second to none."
"Exactly," agreed the old man pleasantly, with a hint of taunting amusement. "Italy, on the other hand, is one of the least prosperous nations on earth. And the Italian fighting man is probably second to all. And that's exactly why my country is doing so well in this war while your country is doing so poorly."
Nately guffawed with surprise, then blushed apologetically for his impoliteness. "I'm sorry I laughed at you," he said sincerely, and he continued in a tone of respectful condescension. "But Italy was occupied by the Germans and is now being occupied by us. You don't call that doing very well, do you?"
"But of course I do," exclaimed the old man cheerfully. "The Germans are being driven out, and we are still here. In a few years you will be gone, too, and we will still be here. You see, Italy is really a very poor and weak country, and that's what makes us so strong. Italian soldiers are not dying any more. But American and German soldiers are. I call that doing extremely well."
Nately guffawed with surprise, then blushed apologetically for his impoliteness. "I'm sorry I laughed at you," he said sincerely, and he continued in a tone of respectful condescension. "But Italy was occupied by the Germans and is now being occupied by us. You don't call that doing very well, do you?"
"But of course I do," exclaimed the old man cheerfully. "The Germans are being driven out, and we are still here. In a few years you will be gone, too, and we will still be here. You see, Italy is really a very poor and weak country, and that's what makes us so strong. Italian soldiers are not dying any more. But American and German soldiers are. I call that doing extremely well."