INTEODUCTION. 11 



Again, Addison says : — 



I look upon instinct as upon the principle of gravitation in 

 bodies, which is not to be explained by any known qualities 

 inherent in the bodies themselves, nor from any laws of me- 

 chanism, but as an immediate impression from the first Mover, 

 and the Divine energy acting in the creatures. 



This mode of ' looking upon instinct ' is merely to 

 exclude the subject from the sphere of inquiry, and so to 

 ■abstain from any attempt at definition. 



Innumerable other opinions might be quoted from 

 well-known writers, 'looking upon instinct' in widely 

 different ways ; but as this is not an historical work, I 

 shall pass on at once to the manner in which science 

 looks upon it, or, at least, the manner in which it will 

 always be looked upon throughout the present work. 



Without concerning ourselves with the origin of in- 

 stincts, and so without reference to the theory of evolution, 

 we "have to consider the most conspicuous and distinctive 

 features of instinct as it now exists. The most important 

 jDoint to observe in the first instance is that instinct 

 involves Tnental operations ; for this is the only point 

 that serves to distinguish instinctive action from reflex. 

 Reflex action, as already explained, is non-mental neuro- 

 muscular adaptation to appropriate stimuli; but in- 

 stinctive action is this and something more ; there is in 

 it the element of mind. Such, at least, is instinctive 

 action in the sense that I shall always allude to it. I 

 am, of course, aware that the limitation which I thus 

 impose is one which is ignored, or not recognised, by 

 many writers even among psychologists ; but I am per- 

 suaded that if we are to have any approach to definiteness 

 in the terms which we employ — not to say of clear- 

 ness in our ideas concerning the things of which we speak 

 — it is most desirable to restrict the word instinct to 

 mental as distinguished from non-mental activity. No 

 doubt it is often difficult, or even impossible, to decide 

 whether or not a given action implies the presence of the 

 mind-element — -i.e., conscious as distinguished from un- 

 conscious adaptation ; but this is altogether a separate 

 matter, and has nothing to do with the question of 



