240 THE FEELINGS AND EMOTIONS 
interesting things from each other, and from their reiatively 
uninteresting surroundings, must be accompanied by some 
differentiation of these things from themselves as affected by 
them and reacting to them. So that here, as we have seen 
to be the case in other matters, what is commonly called the 
perceptual life of animals affords the rough-hewn materials 
from which ideal constructions may be elaborated by rational 
beings. 
We cannot here attempt to do more than barely indicate 
the manner in which the perceptual process in animals may 
acquire unity and diversity—unity through the functioning of 
the same brain and body, diversity from the different modes 
of functioning and the differential effects of diverse modes 
of stimulation. The interesting point for us in our special 
inquiry is that it is through behaviour that all this is brought 
about. 
As we interpret the facts, the restless activity of the young 
is primarily a biological fact, and is to be dealt with as an 
organic problem—a complication of the fundamental irritability 
of protoplasm. But it is also an essential condition to the 
acquisition of conscious experience ; and the more there is of 
it in varied modes the wider is the range of the data afforded 
to consciousness. Congenital behaviour is thus the goal of 
organic heredity, and the starting-point of conscious accom- 
modation and adjustment ; it is the biolegical end of variation, 
and affords the means to intelligent modification. 
So much for some of the results of conative tendency. 
Not only does it secure adaptation or adjustment to the 
environment, but it affords the conditions of mental develop- 
ment by which further accommodation is rendered possible. 
But, in addition to the attainment of biological ends, in 
addition to the furtherance of survival in the struggle for 
existence, mental development has another aspect. All sensory 
data, whether from the special senses, from the motor processes 
concerned in responsive behaviour, or from other sources, may, 
and perhaps always do, carry with them some amount of what 
is termed /fee/ing-tone, giving rise to a net result in consciousness 
