thus an identity in man's native
endowment between what he can do and what he wants to do.
Instincts must thus be regarded as both native capacities and
native desires.

Instincts define, therefore, not only what men can do, but
what they want to do. They are at once the primary instruments
and the primary provocatives to action. As we shall
presently see in some detail, human beings may acquire
mechanisms of behavior with which they are not at birth
endowed. These acquired mechanisms of response are called
habits. And with the acquisition of new responses, new motives
or tendencies to action are established. Having learned
how to do a certain thing, individuals at the same time learn
to want to do it. But just as all acquired mechanisms of
behavior are modifications of some original instinctive
response, so all desires, interests, and ideals are derivatives of
such original impulses as fear, curiosity, self-assertion, and
sex. All human motives can be traced back to these primary
inborn impulses to make these primary inborn responses.[1]

[Footnote 1:
The clearest statement of the status of instincts as both mechanisms of
action and "drives" to action has been made by Professor Woodworth in his
_Dynamic Psychology_. No one else, to the best of the author's knowledge,
has made the distinction with the same clarity and emphasis, though it has
been suggested in the work of Thorndike and McDougall. In McDougall's
definition of an instinct he recognizes both the responsive self and the
tendency to make the response. An instinct is, for him, an inherited
disposition which determines its possessor, in respect to any object,
"to act in regard to it in a particular manner, or at least to
experience an impulse to such action."]

THE NECESSITY FOR THE CONTROL OF INSTINCT. The human
being's original equipment of impulses and needs constitutes
at once an opportunity and a problem. Instincts are the
natural resources of human behavior, the raw materials of
action, feeling, and thought. All behavior, whether it be the
"making of mud pies or of metaphysical systems," is an
expression, however complicated and indirect, of some of the
elements of the native endowments of human beings.
Instinctive tendencies are, as we have seen, the primary motives
and the indispensable instruments of action. Without them
there could be no such thing as human purpose or preference;
without their utilization in some form no human purpose
or pref