SOURCES AND ENDS OF HUMAN EFFORT 333 



while in actual operation, may draw upon certain 

 biological reserves (present in every organism) and 

 so exhibit a characteristic physiological pressure or 

 "drive." 



If we apply the expression "a push from behind" 

 to these hereditary and habitual impulsions, we use 

 figurative language. Neither heredity nor habit is a 

 force, but these are expressions of fixed structural 

 molds through which certain of the vital energies 

 must come to expression (if at all) and by which the 

 character of this expression is determined. 



Josey (1922) has, in fact, fallen into a grievous 

 fallacy here. In attacking certain appeals to mystical 

 forces as determiners of human behavior (which still 

 persist in some quarters) he goes too far and in effect 

 denies the practical significance of any innate factors 

 in behavior. These innate factors are not extraneous 

 "forces" or metaphysical agents; they are stable pat- 

 terns of protoplasmic activity, and as such, they are 

 true causative factors in behavior. 



The driving power of impulse is derived not at all 

 from mythical hereditary "forces" and in very small 

 measure from the physical energy of the stimulus 

 which sets off the impulsive process. The internal 

 sources of this impulsive energy are of two sorts. 

 First, there are the general bodily reserves of energy 

 in excess of immediate needs normally present in 

 every healthy organism, to which in higher animals 

 there are added elaborate devices for step-up of en- 



