 Notice that according to this formulation, health is not just the absence of disease but a positive state of well-being and flourishing (notoriously ambiguous concepts in themselves). Although quality of life is often cited as critical to definitions and theories of health, many commentators are wary of the expansiveness of a definition similar to the WHO’s terminology, as it seems to encompass many things beyond the health of the individual which could contribute (or diminish) his or her “well-being”.