THE PSYCHOLOGICAL ASPECT 321 
under their biological aspect not less important than the former, 
are under their psychological aspect of perhaps even greater 
importance. For the conditions of actual struggle are not 
those under which mental development could most easily be 
furthered, though they are those in which it is most effectually 
tested. Hence, the more intelligent animals pass through a 
period during which they are more or less shielded from the 
incidence of natural selection by their parents, and this is the 
period of play and of psychological education. And the tendency 
to play is so far organic, in that it is dependent on inherited 
instinctive propensities, and so far psychological in that it is 
accompanied by a felt want, which constitutes a conative 
impulse finding its appropriate end in the consciousness of 
satisfaction. But play—if we accept the term as the group- 
name for all those modes of behaviour which fall under our 
second class, those of indirect biological value—does not cease 
with the period of youth ; it occupies all the intervals in the 
more serious business of animal life. And no discussion of animal 
behaviour can be adequate which does not assign to this class its 
due place, alike in biological and in psychological evolution. 
The whole value of experience lies in the linkage and 
coalescence of the data afforded to consciousness. It is true 
that an inherited nervous system supplies the organic con- 
ditions of that physiological linkage and functional coalescence 
of which experience is the psychological expression. It is true 
that this physical integration secures a ready-made grouping of 
the conscious data which are the concomitants of orderly mole- 
cular changes in the brain or analogous sensorium. Still, it also 
remains true that the value of experience lies in the further 
linkage and coalescence that is acquired by the individual in 
the course of what we may fitly call its education. Every step 
in this education gets its psychological sanction through the 
satisfaction it affords in consciousness; and the time of 
acquisition is not during the stress of examination in the 
actual struggle for existence, but rather in the youthful period 
and in the subsequent intervals of preparation and practice 
during the play-time of animal life. 
Y 
