In the long history of the western and eastern philosophy, war has been regarded as one of the most important and famous themes. I would like to clearly explain what is the military leadership theory of Plato(republic) and Sun Tzu(the art of war), and why the study of military leadership through humanities classics is so important to the Republic of Korea in the 21st century, especially the time period of fourth Industrial Revolution featured by convergence and Integration. As well known, Plato's Republic is one of the most important western classics in the political theory. According to Plato, war cannot be regarded as the aim of nation(polis) ruling, but the attack of enemies from the outside should be overcome. In this work we can also find the reason and method of how to prepare and fight against the enemies during the war period. According to Plato war is de facto unavoidable in the human world, because it is rooted in the nature of human being. We should exactly understand that the effective education of guardians is the best way to prepare and overcome the war. In the long history of the ancient china, for example, the period of the spring and autumn and the warring states, war has been regarded as one of the most important and serious subjects through the empire ruling. But war is not a last goal of political acts, but just a quick and safe way to the peace and empire organization. Sun Tzu's world-famous military method work called "the art of war" shows us how to win field fighting and overcome dangerous situations during the war period. He emphasizes that the best way to the victory in the war field is not the number of arms or soldiers, but the authentic power and field leadership of the officer group. So, the long and proper education and hard training of the officer group(the military guardians) have been emphasized.