Husserl the philosopher personally experienced World War I breaking out 100 years ago. Like most German and Austrian commoners, at the initial stage of the war, Husserl was extremely passionate for it. After undergoing the cruelty of war and losing many relatives and friends, he was once enmeshed in extreme confusion and disappointment, albeit he still made every effort to offer spiritual and ethical support to the soldiers at the front. Along with the proceeding of the war, he soon changed his views with respect to this war and confessed that more and deeper reflections were needed to address issues about problems of nationality, super-national ethics and about problems of wars relevant to them. He made philosophical theoretical reflections with regard to this war after it ended, and presented, eventually, requirements for himself: to be satisfied with taking the possibility of the practical activities of philosophy as the topic of philosophical theoretical study and to give up, in drastic fashion, the intention in such philosophical practices as providing political proposals and exerting political influences, “living purely as a scientific philosopher.”