action(praxis). Broadly speaking, an action is what we do. The verb for doing something isprattein. More strictly, praxis is what we do deliberately. Ethics is a practical reasoning because it is about praxis, what we do deliberately.
appropriate action(kathekon). This participial form of the verb katheko indicates what is fitting and proper. Stoics usually used the word in the plural (ta kathekonta) to indicate actions that are appropriate for a human being to perform. They contrasted these with ta katorthoma, which are a subset of appropriate actions—the right actions. Only right actions are truly virtuous. A person who is kind to his or her parents performs appropriate actions; however, they are not right actions unless he or she performs them for the right reasons. Acts of kindness performed to enhance one's reputation or to gain the inheritance, for example, are appropriate actions but they are not right or virtuous actions. In later writers (toward the first century B.C.E.), kathekon acquired the notion of duty—it is not only proper for children to take care of their parents, it is their duty. Cicero translated kathekonta into Latin as officia, duties. The original Stoic idea, however, did not so much connote duty as the appropriateness of actions regardless of whether or not they were performed for the right reason.
character(ethos). The best translation of ethos (spelled with a long [e]) is probably moral character or simply character. Character is related to habit (ethos spelled with a short [e]) but it is not the same. Both habits and character can be good or bad. Good character is acquired in two stages. The preliminary stage occurs