 While Aristotle shares with Plato a concern for cultivating virtues, he gives greater theoretical attention to the role of choice in initiating individual actions which, over time, result in habits, for good or ill. In Book III of the Nicomachean Ethics, Aristotle says that, unlike nonrational agents, we have the power to do or not to do, and much of what we do is voluntary, such that its origin is ‘in us’ and we are ‘aware of the particular circumstances of the action’. Furthermore, mature humans make choices after deliberating about different available means to our ends, drawing on rational principles of action. Choose consistently well (poorly), and a virtuous (vicious) character will form over time, and it is in our power to be either virtuous or vicious.