What is it that makes a man who he is? What causes him to make certain decisions - to take certain actions over others? The beliefs and values of a human being are the only reasons for which a free person will act. Marcus Aurelius, Emperor of Rome from 161 to 180 AD, was aware of this fact, and sought to rule his conscious will with supreme reason, the dispassionate thinking process through which decisions are made, in accordance to Nature. A free person is not ruled by emotions, and does not base decisions upon externals at all, but will always act according to his or her ruling reason. Marcus sought to embody the true philosopher, one whose reason guided all and whose behavior flowed from that rationality into the practical application of living. Being human, it is in his nature to live in communion with others and fulfill the duties for which he was born. His love for Philosophy, and his lifetime spent seeking after her, formed his potest?s, or ruling power. This ruling power is over the self as well as over the world in which one lives. Humans are citizens of the world, and as citizens have duties to the world as a political realm. In order to actualize this human potential to its fullest, Marcus believed in doing his duty for Rome and also for himself. Marcus Aurelius’ beliefs in Stoicism are reflected in all of his actions and musings, and are the foundation for his political rule and influence in Rome.