'Our physical requirements also happen to be the ones that can be both most easily defined and objectively measured. The availability of food and water, for example, can readily be assessed by scientists and governments. The same goes for the availability of adequate shelter. Things like adequate educational opportunities and access to healthcare are only slightly more subjective and difficult to quantify.But as we move into the psychological realm, things quickly start to get fuzzy. While everyone may be said to have intellectual and emotional needs, or even spiritual ones, how these are defined and satisfied can vary a great deal from one person to the next. There is no guarantee that satisfying the physical requirements of existence will lead to emotional or spiritual well-being.'