ANTS AND SOME OTHER INSECTS. 7 



the physiology of the brain (observation of brain-activity from with- 

 out), we shall take the theory of identity for granted so long as it 

 is in harmony with the facts. The word identity, or monism, im- 

 plies that every psychic phenomenon is the same real thing as the 

 molecular or neurocymic activity of the brain-cortex coinciding 

 with it, but that this may be viewed from two standpoints. The 

 phenomenon alone is dualistic, the thing itself is monistic. If this 

 were otherwise there would result from the accession of the purely 

 psychical to the physical, or cerebral, an excess of energy which 

 would necessarily contradict the law of the conservation of energy. 

 Such a contradiction, however, has never been demonstrated and 

 would hold up to derision all scientific experience. In the mani- 

 festations of our brain-life, wonderful as they undoubtedly are, 

 there is absolutely nothing which contradicts natural' laws and jus- 

 tifies us in postulating the existence of a mythical, supernatural 

 "psyche." 



On this account I speak of monistic identity and not of psycho- 

 physical parallelism. A thing cannot be parallel with itself. Of 

 course, psychologists of the modern school, when they make use of 

 this term, desire merely to designate a supposed parallelism of 

 phenomena without prejudice either to monism or dualism. Since, 

 however, many central nervous processes are accessible neither to 

 physiological nor to psychological observation, the phenomena ac- 

 cessible to us through these two methods of investigation are not 

 in the least parallel, but separated from one another very unequally 

 by intermediate processes. Moreover, inasmuch as the dualistic 

 hypothesis is scientifically untenable, it is altogether proper to 

 start out from the hypothesis of identity. 



It is as clear as day that the same activity in the nervous sys- 

 tem of an animal, or even in my own nervous system, observed by 

 myself, first by means of physiological methods from without, and 

 second, as reflecting itself in my consciousness, must appear to me 

 to be totally different, and it would indeed be labor lost to try to 

 convert the physiological into psychological qualities or vice versa. 

 We cannot even convert one psychological quality into another, so 

 far as the reality symbolised by both is concerned ; e. g., the tone, 



