Translation from Hering 67 



above-named — matter and consciousness — stand in the 

 relation of cause and effect, antecedent and consequence, 

 to one another. For on this subject we know nothing. 

 The materialist regards consciousness as a product or 

 result of matter, while the idealist holds matter to be a 

 result of consciousness, and a third maintains that matter 

 and spirit are identical ; with all this the physiologist, 

 as such, has nothing whatever to do ; his sole concern 

 is with the fact that matter and consciousness are functions 

 one of the other. 



By the help of this hypothesis of the functional inter- 

 dependence of matter and spirit, modern physiology is 

 enabled to bring the phenomena of consciousness within 

 the domain of her investigations without leaving the 

 terra firma of scientific methods. The physiologist, as 

 physicist, can follow the ray of light and the wave of sound 

 or heat till they reach the organ of sense. He can watch 

 them entering upon the ends of the nerves, and finding 

 their way to the cells of the brain by means of the series 

 of undulations or vibrations which they establish in the 

 nerve filaments. Here, however, he loses all trace of them. 

 On the other hand, still looking with the eyes of a pure 

 physicist, he sees sound waves of speech issue from the 

 mouth of a speaker ; he observes the motion of his own 

 limbs, and finds how this is conditional upon muscular 

 contractions occasioned by the motor nerves, and how 

 these nerves are in their turn excited by the cells of the 

 central organ. But here again his knowledge 'fcomes to an 

 end. True, he sees indications of the bridge which is to 

 carry him from excitation of the sensory to that of the 

 motor nerves in the labyrinth of intricately interwoven 

 nerve cells, but he knows nothing of the inconceivably 

 complex process which is introduced at this stage. Here 

 the physiologist will change his standpoint ; what matter 

 will not reveal to his inquiry, he will find in the mirror, 

 as it were, of consciousness ; by way of a reflection, indeed, 

 only, but a reflection, nevertheless, which stands in intimate 



