奧古斯丁在《上帝之城》中提出了兩種類型的戰爭，即人與人之間的外在戰爭以及人的靈魂的內在戰爭。由此出發，他通過比較野蠻人與羅馬人在戰爭中的表現，對羅馬的戰爭歷史進行了重構。他將人與人之間的外在戰爭視為人心內部的戰爭的外在反映與必然結果，創造性地開啟了內在的正義戰爭的主題。奧古斯丁同亞里斯多德一樣對戰爭做出了目的論解釋，認為兩種戰爭的起點與目的都是和平。但是，他堅持認為，人的此世既無法擺脫外在的戰爭狀態，亦無法擺脫內在的戰爭狀態，而只能帶著對永久和平的希望而戰鬥。

Augustine proposes two types of war in The City of God, the external war between people and the internal war within the soul, according to which he reconstructed the war history of Rome by comparing the performance between barbarians and Romans. He views external wars among people as an expression and inevitable consequence of the internal war, initially creating the topic of the internal just war. Following Aristotle, Augustine deals with his theory of war within the framework of teleology and thus regards the starting point of the two wars as well as their goal as peace. However, he insists that earthly people can never escape from the state of both external war and internal war, and the right thing for them is to wage war in the hope of eternal peace.