Just as man possesses specific psychological capacities, by virtue of his distinctive form of consciousness, his
conceptual faculty—so, by virtue of this same faculty, he possesses specific psychological needs. (I shall discuss
some of these needs in Part Two.)
When a physical or psychological need fails to be fulfilled, the result is danger to the organism: pain, debilitation,
destruction. However, needs differ (a) in the degree of their temporal urgency, and (b) in the form of the threat
which they potentially pose. This is most easily seen in the case of physical needs, but the principle applies to all
needs.
(a) Man has a need of oxygen and of food; but whereas he can survive for days without food, he can survive for
only minutes without oxygen. Man can survive much longer without Vitamin C than without water; but both are
needs. In some cases, the frustration of a need results in immediate death; in other cases, the process can take years.
(b) Man has a need to maintain his body temperature at a certain level; he has internal adaptive mechanisms which
adjust to changes in the external environment. If he is exposed to extreme temperatures beyond the power of his
adaptive mechanisms to cope with, he suffers pain and, within a few hours, dies. In such a case, the disastrous
consequences of need—frustration are direct and readily discernible; similarly with oxygen deprivation, food
deprivation, etc. But there are instances of need-frustration in which the sequence of disaster is much less direct.
For example, man has a need of calcium; there are regions in Mexico where the soil contains no calcium; the
inhabitants of these regions do not perish outright, but their growth is stunted, they are generally debilitated, and
they are prey to many diseases to which the lack of calcium makes them highly susceptible. They are impaired in
their general ability to function. Thus, a need-frustration does not have to result in the organism's destruction
directly; instead, it can undermine the organism's overall capacity to live, and thus make the organism vulnerable to
destruction from many different sources. (This principle is important to remember in considering the frustration of
psychological needs; we will have occasion to recall it in Chapter Twelve.)
Science comes to discover man's various needs through the consequences that occur when they are frustrated.
Needs