In the same way that a “virtuous” (or excellent) hammer is one that performs well the function for which it was designed—namely, to drive nails—a virtuous individual is one who performs well the function for which humans were designed. To be virtuous, then, is to live as we were designed to live; it is to live, as Zeno put it, in accordance with nature.18 The Stoics would add that if we do this, we will have a good life.
