The path laid clear before him. He had begun to have an inner conviction and learn true values. He started to write novels not for himself, but for human being. However, peace and the sense of fulfillness were soon destroyed. His personality affected by his family, his gift in language and literature and his thoughts influenced by his friends made him oppose the war and became a pacifist. "I never loved that old earth more than in those last years before the First World War, never hoped more ardently for European unity, never had more faith in its future than then, when we thought we saw a new dawning. But in reality it was the glare of the approaching world conflagration."(192) He, a writer, then stood up against war, though as isolated instead of united. He proceeded to Switzerland at once, and visited Romain Rolland. They appealed to hold a meeting and invite celebrities to come in order to promote the unification of Europe. However, German writer Hauptmann refused to come and Thomas Mann was still influenced by nationalism.
During the period of the First World War and the post-war years, he witnessed so-called human misery, which influenced and reflected on his literature work. In 1914, he served in the Archives of the Ministry of War. In 1915, he received the order and went to the frontline of Poland. He then was forced to be a defenseless, helpless witness of the pain and disasters. "I had recognized the foe I was to fight-false heroism that prefers to send others to suffering and death, the cheap optimism of the conscienceless prophets, both political and military who, boldly promising victory, prolong the war, and behind them the hired chorus, the 'word makers of war' as Werfel has pilloried them in his beautiful poem." (252)He chose those prophets as the protagonists for his tragic play Jeremiah. He wasn't intended to write a "pacifist" play, or to tell in the words that peace was better than war.