Assuming that virtues are habits, this chapter will shed light on what kind of habits the virtues are by calling attention to Aristotle and Thomas Aquinas’s account of habit. For Aristotle our nature requires that we acquire a second nature, which is constituted by habits. Aristotle also thought how one becomes proficient in a craft to be quite similar to how one acquires the habits necessary to become a person of virtue. For Aquinas, habits are those qualities that are not easily changed, for the very word habit suggests a lastingness that the word disposition does not. The enduring quality of habits are the result of their relation to acts which are done in a manner that make the agent good as well as the act good. Our habituation is necessary because our appetitive powers, our desires, are underdetermined. Aquinas observes the will by its very nature is inclined to the good of reason, but because this good is varied in a manner, the will needs to be inclined by habit to some good fixed by reason so that the action may follow more readily. We are beings who need habituation because as we have seen we are composed of potentiality and act, making it necessary to be one thing rather than another.