1898.] on Instinct and Intelligence in Animals. 571 



the term instinct, in any particular manifestation off its existence, tbe 

 net result of four things : first, internal messages gi ving rise to the 

 impulse ; secondly, the external stimuli which co-operate with the 

 impulse to aflfect the nervous centres ; thirdly, the active response due 

 to the co-ordinated outgoing discharge ; and fourthly, the message 

 from the organs concerned in the behaviour by which the central 

 nervous system is further aflfected. Now I shall here assume, without 

 pausing to adduce the arguments in favour of this view, that conscious- 

 ness is stirred in the brain only by incoming messages. If this be so, 

 the outgoing discharges which produce the behaviour are themselves 

 unconscious. Their function is to call forth adaptive movements ; 

 and these movements give rise to messages which, so to speak, afford 

 to consciousness information that the instinctive act is in progress. 

 Hence I have urged that the instinctive performance is an organic 

 and unconscious matter of the purely physiological order, though its 

 effects are quickly communicated to consciousness in the form of 

 definite messages from the motor organs. I have not denied that 

 the stimuli of sight, touch, hearing, and so forth, have conscious 

 efiects ; I do not deny (though here I may have spoken too guardedly) 

 that the initiating impulse of internal origin is conscious. In both 

 these cases we have messages transmitted to the central office of the 

 brain. What I have ventured to urge is that the consciousness of 

 instinctive behaviour, in its comjpleted form, does not arise until 

 further messages come in from the motor organs implicated in the 

 performance of the act, lodging information at the central office con- 

 cerning the nature of the movement. A diagram will perhaps serve to 

 make this conception clearer. 



Impulse 



Stimulus 



Instinctive behaviour 



The circle represents the brain, in some part of which conscious- 

 ness arises through the effects of incoming nerve-currents. Under 

 the influence of the two primary groups of messages due to impulse 

 and to sensory stimulus, consciousness is evoked, and the brain is 

 thrown into a state of neural strain, which is relieved by the outgoing 

 discharge to the organs concerned in the instinctive behaviour. It is 

 this outgoing discharge which I regard as unconscious. But the 

 acti(ms which are thus produced give rise to a secondary group of 

 incoming messages from the moving limbs. This it is which gives 

 origin to the consciousness of instinctive behaviour as such. And I 

 regard it as psychologically important that these incoming messages 

 are already grouped so as to afford to consciousness information 

 rather of the net results of movement than of their subsidiary details. 



