1890. | The Evolution of Mind. 901 
The test of the presence of conciousness as the condition of the 
performance of an act is to be found in the nature of the act. Con-: 
sciousness may be supposed to be necessary to the performance of 
an act which displays a definite relation to the satisfaction of some 
need of the animal; but such an act does not necessarily prove 
that consciousness is present at the moment of action. It is well 
known that designed acts may be performed by the higher 
animals which have been deprived of their nervous sensory cen- 
ters. Thus many vertebrates respond to stimuli applied to the ex- 
tremities of their peripheral nervous system after the removal of 
the brain; such movements are entirely appropriate to the stimulus, 
being directed to the removal of the source of the irritation. 
The presence of consciousness (or sensation) cannot be predicated 
on movements of this kind. In fact, many kinds of movements 
of considerable complexity are unconsciously performed by man 
with uninjured sensory centers, in consequence of their sub- 
jection to the process of automatization, which is education, of the 
centers. By continued repetition a given movement may be 
learned, so that consciousness is not necessary to its performance, 
as for instance, knitting and reading aloud. Walking and other 
comparatively simple movements may be still more readily per- 
formed in unconsciousness. It is certain that even some of the 
higher functions of the brain, as classification, may be so performed. 
On account of these well-known phenomena it is supposed by a 
class ofthinkers that consciousness has not been necessary to the 
original performance of any act, no matter how complex it may 
be, and no matter how evident the design. They suppose that 
action has been promiscuous or multifarious, and that natural se- 
lection has preserved those individuals whose movements chanced 
to be beneficial, and that those whose movements have been of a 
useless or injurious kind have been destroyed. 
There are two objections to this explanation of the origin of 
designed movements. The first is, that in all cases where we 
have the opportunity of observing the origin and development of 
such acts, we find that they have to be learned, and that they 
only become automatic after a more or less prolonged period of edu- 
cation. This process of education is one that involves the pres- 
