[Page 2780]Quality of life refers to the degree of excellence in life (or living) relative to some expressed or implied standard of comparison, such as most people in a particular society. The degree, grade, or level to which ‘‘the best possible way to live’’ or ‘‘the good life’’ is attained can range from high to low or good to poor. Usually, quality of life is explicitly or implicitly contrasted with the quantity of life (e.g., years), which may or may not be excellent, satisfying, or enjoyable. To paraphrase the Stoic philosopher Seneca (ca. 4 BCE to 65 CE), who clearly valued quality over quantity, ‘‘It matters with life as with play; what matters is not how long it is, but how good it is.’’ In ...