The concept of right or fit is an important element entailed, but not fully articulated, in the concept of action or practice in Aristotle’s theory of virtue; which, however, turns to be of the utmost importance in later Western ethics. Right is concerned with both feelings and actions, and is not the same for all individuals. It lies in between the two extremes of the spectrum of practical affairs, yet by no means equidistant from them. This account of the concept of fitness or right is derived from the categories of quantity, relationship, and quality rather than from that of substance. Thus, it seems that virtue is relative to vice or error within a continuous existence. If, however, the right of passion and action is environmental and concrete, is it multiple and not singular? To this question, Aristotle gives his reply on two levels: On the level of concrete practitioners, what is right and fit to one man might not be so to another man, and hence the right of practice is not singular but multiple; whereas on the level concerned with the only right choice compared with the two extremes or errors, the right of practice will always be singular.