In Chapter 17, why is Henry overcome by hatred for the enemy? How does his hatred affect his behavior?

Henry gets caught up in the "animal" of war. He sees nothing but the blue line. He feels that his rifle is an impotent stick. He loses everything but his hate. He is soon no longer aware that he stands on his feet. He loses balance, but then quickly stands again. The smoke broils his skin. His rifle barrel grows hotter and hotter, and he continues to stuff it with cartridges. Even after the enemy falls back, and the rest of the regiment has stopped shooting, he continues fighting his foe.