XXVII.] INTELLIGENCE. 5 



intelligent though unconscious motor actions — in a word, 

 by instinct. 



It is impossible to say at what point in the ascending "We cannot 

 scale of organization the mutual action of ganglia and nerve- the'bedn- 

 fibres begins to be accompanied by sensation ; and it is ^ing of 

 equally impossible to say at what point sensation begins or of 

 to develop into consciousness. But what I wish to insist conscious- 



ucss 



on here is, that intelligence is not the same thing with the 

 consciousness of intelligence. Intelligence — a power tran- 

 scending the ordinary properties of matter, and adapting 

 means to pui-poses, — intelligence, I say, presides over all 

 vital actions, whether formative, motor, or mental, directing 

 each action to its specific end ; but it becomes conscious 

 only in mental actions — that is to say, only in thought ; 

 and it becomes perfectly conscious only in mature deli- 

 berate thought. All other thought, including all the Most 

 mental operations of animals and young children, and by pg°{Jfpf' 

 far the greater portion of the mental operations of even tlie all. is 

 most thoughtful men, is in a great degree unconscious, conscious." 

 We cannot tell at what point consciousness becomes per- 

 fect, any more than we can tell where it begins : perhaps, 

 indeed, it is never perfect ; perhaps we have no thoughts 

 of which we are able to give a complete account, even to 

 ourselves. It is however certain, that so far from conscious- 

 ness being necessary to intelligence, unconscious intelli- 

 gence is the rule, and conscious intelligence the exception. 

 If these views which I have stated are true ; and if 

 the intelligence that adapts organic structures to their 

 functions is fundamentally identical with the mental 

 intelligence of man; it follows from the mere statement, 

 that the intelligence which forms the lenses of the eye is identity of 

 the same intelligence which, in the mind of man, nnder- [°™i^g7®' 

 stands the theory of the lens ; the intelligence that hollows tive, and 

 out the bones and the wing-feathers of the bird in order to ™nVence!' 

 combine lightness with strength, and places the feathery 

 fringes where they are needed,^ is the same intelligence 



1 See the explanation of the mechanism of flight, in the Duke of Argyll's 

 " Eeign of Law." The hollowing out of the bones of birds is probably the 

 most wonderful adaptation in the motor system of any animal. 



