PSYCHOLOGY 267 



Invertebrates whose ganglia have practically the value of a brain 

 (ants, bees, spiders, crabs and cephalopods). 



Man's paramount powers of ideation'are due to the size and 

 development of his brain, whose cortex contains countless nerve- 

 cells. It might be supposed that upon the question of conscious 

 ideation in the higher animals there could be no difference of 

 opinion. Tiirkheim, however, denies this faculty to animals 

 with vehemence and every artifice of dialectic. He declares it 

 impossible that an animal can have an "internal mirroring" of 

 something which is not present. The entire psychical apparatus 

 by means of which men know and think, namely, perception, 

 observation and investigation, are completely wanting in 

 animals. " A state of consciousness," he says, " is either ideation 

 or it does not exist." From this point of view he will not 

 even allow that animals have indefinite, confused ideas, for that 

 would naturally be an admission of their consciousness. Their 

 minds are powerless to form any after-picture of impressions 

 conveyed by the eye, ear, nose, tongue or skin. There can be 

 no question of their forming concepts because they have no 

 powers of ideation, only simple sensations ; still less can one 

 attribute to them associations such as exist in man between the 

 feelings and the groups of ideas, or between separate groups of 

 ideas. Yet Turkheim himself admits that animals have associa- 

 tions, just like human beings, partly innate, partly acquired by 

 experience. 



I have quoted freely from Turkheim's book because his 

 statements come as a real surprise to those who like myself 

 have been engaged for many years in experiments with animals, 

 and I have limited myself to criticising only his most striking 

 utterances. 



The truth is that comparing the human infant with the 

 young of any of the higher mammals you please, psychologi- 

 cally the latter are far superior to the human infant. 



And when Turkheim insists that an animal forms no idea 

 of what is not actually before his eyes, he forgets that a dog or 

 horse could not recognise his master at a distance from other 

 men without some internal picture ; nor could a homing-pigeon 

 find his loft or the bee his hive without ideation. To take 

 another instance, the wasp could not find with certainty the 



