This thesis argues that virtue belongs in any framework of moral philosophy, and specifies this along several lines. In the first chapter I establish that virtue is a good, or a duty. I defend this against skeptical objections which argue that virtue is only an instrumental good. In Chapter 2 I specify some features of virtue. I argue that virtue is an attitude toward the good, and also is enhance by an inclination toward action and a stable disposition. Chapter 3 argues against certain meta-ethical objections that would question the veracity of the aspects of virtue discussed in Chapter 2. These objections draw from psychological studies about traits and the telos of a life. Chapter 4 suggests a hypothesis that eudaimonia, or human flourishing defined narrowly can provide the theoretical unification for virtue. / February 2016