INTRODUCTION, 
13 
rational, does this exclusively in the sphere of subjec- 
tivity ; the nervous processes engaged are throughout the 
same in kind, and differ only in the relative degrees of 
their complexity. Therefore, as the dawn of consciousness 
or the rise of the mind-element is gradual and undefined, 
both in the animal kingdom and in the growing child, it 
is but necessary that in the early morning, as it were, of 
consciousness any distinction between the mental and the 
non-mental should be obscure, and generally impossible to 
determine. Thus, for instance, a child at birth does not 
close its eyes upon the near approach of a threatening 
body, and it only learns to do so by degrees as the result 
of experience ; at firs 4 -, therefore, the action of closing the 
eyelids in order to protect the eyes may be said to be 
instinctive, in that it involves the mind-element : 1 yet it 
afterwards becomes a reflex which asserts itself even in 
opposition to the will. And, conversely, sucking in a 
new-born child, or a child in utero? is, in accordance with 
my definition, a reflex action ; yet in later life, when con- 
sciousness becomes more developed and the child seeks the 
breast, sucking may properly be called an instinctive 
action. Therefore it is that, as in the ascending scale 
of objective complexity the mind -element arises and 
advances gradually, many particular cases which occupy 
the undefined boundary between reflex action and instinct 
cannot be assigned with confidence either to the one region 
or to the other. 
We see then the point, and the only point, wherein 
instinct can be consistently separated from reflex action ; 
viz., in presenting a mental constituent. Next we must 
consider wherein instinct may be separated from reason. 
And for this purpose we may best begin by considering 
what we mean by reason. 
The term 6 reason 5 is used in significations almost as 
various as those which are applied to 6 instinct/ Some- 
I.e ancestral as well as individual. If the race had not always 
had occasion to close uhe eyelids to protect the eyes, it is certain that 
the young child would not so quickly learn to do so in virtue of its 
own individual experience alone ; and as the action cannot be attri- 
buted to any process of conscious inference, it is not rational ; but wa 
have seen that it is not originally redex ; therefore it is instinctive. 
