358 THEORETICAL BIOLOGY 



appearance of certain qualities in our mind after stimulation 

 of certain sensory nerves. 



His theory goes beyond the mere physiological demon- 

 stration that the same steering in the centre is connected 

 with the excitation of the same centripetal fibres. It speaks 

 of a " specific," non-mechanical energy, which is active when 

 the qualities appear in the mind ; and only in the second 

 place does it point out that the nature of the quality that 

 appears is connected with the person of the nerves in which 

 this " super-mechanical " energy becomes effective. 



Now, as I have stated, in super-mechanical processes, 

 impulses always come in determinatively ; they are specific 

 life-energies. If we wish to follow Johannes Muller, we must 

 assume that the impulses which invade our mark-organ 

 determinatively and create new forms, are in essence qualities. 



For the representational idea that we made of these 

 processes, this assumption is unimportant. It is of no interest 

 to the outside observer whether the amoeba-like centres 

 in stretching forth their pseudopodia to make new bridges 

 for excitation, receive the order to build the bridge in the 

 form of " a way for blue " or " a way for red." The content 

 of the subjective mark-sign in the active brain during the 

 building of new bridges is a matter of indifference to the 

 observer. He need only pay regard to the nature of the 

 external stimulus to which the bridge-building gives the 

 opportunity of entering determinatively into the steering of 

 the action. From these objective indications he will construct 

 the sensed- world of animals, i.e. he will always employ his 

 own qualities, from which he constructs the world, to describe 

 the sensed- world of animals. In so doing, he will make 

 no distinction as to whether the indications released by the 

 stimuli determined the actions in a reflex or in a plastic 

 manner. All indications are equally necessary for the con- 

 struction of the world-as-sensed. 



