The most widely accepted definition of health is that of the World Health Organization Constitution. It states: "health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" (World Health Organization, 1946). In more recent years, this statement has been amplified to include the ability to lead a "socially and economically productive life". The WHO definition is not without criticism, mainly that it is too broad. Some argue that health cannot be defined as a state at all, but must be seen as a dynamic process of continuous adjustment to the changing demands of living.