ft. E. MEZES — MAN A KB* OTHER ANIMALS. 
37 
special occupation, and acquired instead the general function of assist- 
ing the performance of difficult actions; thirdly, it must be borne in 
mind that skillful use of the hand could not be obtained without a 
large amount of brain coordination, and that there is much evidence to 
show that intelligence develops, and still develops, as hand-directing in- 
telligence; and finally it is not impossible that, owing to the spinal 
changes accompanying hand-changes, the movements and tensions in- 
cident to erectness and throwing back of the shoulders should be aroused 
also by difficult situations. 
Now all these facts, properly weighed, point with some probability to 
the process of humanization as beginning on the physical side in diffi- 
cultly coordinated hand-movements, and on the mental side in the 
organization and generalization of effort, the central fact of volition. 
Stated in bare outlines, the hypothesis is that these hand-movements, 
bringing into play the muscles of the arm and shoulder as well, and also, 
owing to the advantage of the erect posture for hand-use, those of the 
back, and further, for reasons suggested above, the jaw muscles — that 
these hand -movements, assisted by their associates, proved especially 
effective in many difficult situations, and thus gradually came to be 
aroused more and more, constantly on such occasions, with increasing 
effectiveness, the result finally being that, whenever a movement did 
not correspond to the idea arousing it, this idea aroused, and was sup- 
ported by, that group of muscular movements, with effort or endeavor, 
and not infrequently accomplishment, as the outcome. The hypothesis 
is mentioned merely as a conjecture, though, as it. seems to the present 
writer, not an improbable one. What he regards as all but undoubtedly 
sound, is the simpler hypothesis that volition, purposeful action, is the 
distinctive characteristic of man. If, however, the broader physio- 
psychic hypothesis is accepted, it still remains to show the conditions 
that called forth the difficult and signally effective hand-movements, 
with all that followed in their train. This may have been accomplished, 
as Professor Giddings suggests, by association — pre-volitional, however 
— or, as Dr. Fisk believes, by prolonged childhood, or by some other 
means so far unknown. 
