In the history of philosophy, Thomas Aquinas has for a long time been seen asa Scholastic Aristotelian. This view has exerted a huge influence on the contemporary interpretation of Aquinas' virtue ethics. In fact, this doctrine has seriously obscured the originality of Aquinas's thought, and furthermore, it has also led to the long-term neglect of his virtue theory. Although Aquinas inherited diverse aspects of Aristotelian virtue theory, in his own unique way, he then transformed the content of virtue and the whole structure of Aristotle's virtue ethics that centered on secular reason. Aquinas borrowed Aristotle's philia and created the unique concept of Human-God friendship, amicitia. By making amicitial the form of all virtues, Aquinas constructed a new theological system of virtue ethics that unifies Christian virtue theories, as well as those of the Greek tradition. In this sense, Aquinas succeeded in transforming Aristotelian virtue ethics.