The Study of Consciousness and. Behavior gs 
reprinted in this volume produced in their author an in- 
creased respect for psychology as the science of behavior, 
a willingness to make psychology continuous with physi- 
ology, and a surety that to study consciousness for the sake 
of inferring what a man can or will do, is as proper as to 
study behavior for the sake of inferring what conscious 
states he can or will have. This essay will attempt to 
defend these positions and to show further that psychology 
may be, at least in part, as independent of introspection 
.as physics is. 
A psychologist who wishes to broaden the content of 
the science to include all that biology includes under the 
‘term ‘behavior,’ or all that common sense means by the 
-words ‘intellect’ and ‘character,’ has to meet certain 
onjections. The first is the indefiniteness of this content. 
‘Che indefiniteness is a fact, but is not in itself objection- 
able. It is true that by an animal’s behavior one means 
the facts about the animal that are left over after geometry, 
physics, chemistry, anatomy and physiology have taken 
their toll, and that are not already well looked after by 
sociology, economics, history, esthetics and other sciences 
dealing with certain complex and specialized facts of be- 
havior. It is true that the boundaries of psychology, 
from physiology on the one hand, and from sociology, 
economics and the like on the other, become dubious and 
changeable. But this is in general a sign of a healthy 
condition in a science. The pretense that there is an im- 
passable cleft between physiology and psychology should 
arouse suspicion that one or the other science is studying 
words rather than realities. 
The same holds against the objection that, if psychology 
is the science of behavior, it will be swallowed up by biol- 
ogy. When a body of facts treated subjectively, vaguely 
