128 HABIT AND INTELLIGENCE. [cHAP. 



of H. Spencer, have shown that Berkeley's theory is really 

 consistent with all the facts, and that the difficulty is only 

 apparent. The question is, how is the duck able to recog- 

 nise water without having seen water, and to swim with- 

 Explana- out having learned to swim ? And the answ^er is, that these 

 tlie^e are ^^^ habits which have become hereditary and consequently 

 cases of instuictive. The race has learned them, and they are con- 

 habit, sequently instinctive in the individual. The individual 

 has learned them, not in itself but in its ancestors. But 

 the power of perceiving by means of sight, which power is 

 obviously implied in the duck running to the water when 

 it sees it, is, in the duck as well as in man, purely the 

 result of experience ; only that in man it is the experience 

 of the individual, in the duck it is that of the race. 



I do not deny that the explanation is in some degree 

 hypothetical, for there is no possible test for deciding what 

 are the results of habit, and what of unconscious organic 

 intelligence, acting independently, or as it were in antici- 

 pation of habit. But the explanation I have offered, in 

 which, I believe, every authority would now agree, has the 

 only proof of which the nature of the case admits : that is 

 to say, the cause alleged is known to exist, and is adequate 

 to produce the effect. 



As I have stated at the beginning of this chapter, I 

 believe that perception is neither a simple act nor an 

 inexplicable one, but merely the simplest of all cases of 

 Presump- inference. The fact that we perceive not by one but by 

 perception several distinct senses is enough to raise a very strong 

 is not a presumption that perception is not a simple inexpKc- 

 from the ' ^^^^^ ^^^' ^^^ one that admits of analysis and explana- 

 multiph- tion. And what raises the probability, I think, to a cer- 



Clty of . • T r. -1 ■ P 1 • 



senses. tamty, IS the familiar fact that in many cases we are at a 

 loss whether we ought to refer the sensation to anything 

 external, or to account for it by the disordered state of the 

 o/the" ^ organic system. The multiplicity of the senses is, however, 

 subject, a cause of difficulty in the understanding of the subject ; 

 multipli- ^iid it is still further complicated by the combination, in 

 city, and h^q most important class of perceptions, of impressions 

 binatioii. derived from the two senses of touch and sight. It is 



