especial significance in social life.

In the first place, we must note the three great primary
drives of human action, the unlearned and native demands
for food, shelter, and sex gratification.[1] Although the last-named
does not display itself in human beings until a considerable
degree of maturity has been attained there is indubitable
evidence that it is an inborn and not an acquired reaction.
The practical utility of the first two is apparent; they are the
most essential features of the group of so-called self-preservative
instincts, among which may be grouped the natural
tendency to recover one's equilibrium and the instinct of
flight in the face of dangerous or threatening objects. The
utility of the sex instinct is racial rather than individual. The
instinctive satisfaction human beings find in sex gratification
is the natural guarantee of the continuance of the race.

[Footnote 1: The reader must be reminded that the simpler reflexes
involved in the use of the heart, lungs, intestines, and all the
internal organs, must be classed as part of man's native equipment.
They differ from those reactions commonly classed as instincts in
that they are simpler and stabler, that in their normal functioning
they never rise to consciousness, and that they are almost completely
beyond the individual's modification or control.]

In a general survey of this nature it IS impossible, as it is
unnecessary, to examine in detail the physiological elements
of the demand for food and shelter. It will suffice to point
out that the first two are the ultimate biological bases of a
large proportion of our economic activities. They are primary,
not in the sense that they are constantly conscious
motives to action, but that their fulfillment is prerequisite to
the continuance of any of the other activities of the organism.
Agriculture and manufacture, the complicated systems of
credit and exchange which human beings have devised, are,
for the most part, contrivances for the fulfillment of these
fundamental demands. With the complexity of civilization
new demands, of course, arise, but these fundamental necessities
are still the ultimate mainsprings of economic production.

The demand for sex gratification, because of its enormous
driving force and the emotional disturbances connected with
it, offers a peculiarly acute instance of the difficulties brought
about in the control of man's native endowment in his own
best interest. While