CONSCIOUSNESS. 7o 



them into more and more complex and varied relations with 

 their environment), the primitive assignment of a special 

 nervous mechanism to meet the exigencies of this or that 

 special group of stimuli becomes no longer practicable, and 

 the higher nerve-centres have therefore to take on the func- 

 tion of focussing many and more or less varied stimuli, in 

 order to attain to that higher aptitude of discrimination in 

 which we have already seen to consist the distinctive attri- 

 bute of Mind. And, as Mr. Spencer has observed, " the co- 

 ordination of many stimuli into one stimulus is, so far as it 

 goes, a reduction of diffused simultaneous chanires into con- 

 centrated serial changes. AVhether the combined nervous 

 acts which take place when the fly-catcher seizes an insect 

 are regarded as a series passing through its centre of co- 

 ordination in rapid succession, or as consolidated into two 

 successive states of its centre of co-ordination, it is equally 

 clear that the changes going on in its centre of co-ordination 

 have a much more decided linear arrangement than have the 

 changes going on in the scattered ganglia of a centipede." 

 And this linear character of the change is, of course, one of 

 the most distinctive features of consciousness as known to 

 ourselves subjectively. 



It will have been observed that this interpretation of the 

 rise of consciousness is purely empirical. We know by 

 immediate or subjective analysis that consciousness only 

 occurs when a nerve-centre is engaged in such a focussing 

 of varied or comparatively unusual stimuli as have been 

 described, and when as a preliminary to this focussing or act 

 of discriminative adjustment there arises in the nerve-centre 

 a comparative turmoil of stimuli coursing in more or less 

 unaccustomed directions, and therefore giving rise to a com- 

 parative delay in the occurrence of the eventual response. 

 But we are totally in the dark as to the causal connection, if 

 any, between such a state of turmoil in a ganglion and the 

 occurrence of consciousness. Whether it is the Angel that 

 descends to trouble the waters, or the troubling of the waters 

 that calls down the Angel, is really the question which divides 

 the Spiritualists from the Materialists ; but with this question 

 we have nothing to do. It is enough for all the objects of 

 the present work that we never get the Angel without the 

 troubling, nor the troubling without the Angel ; we have an 

 empirical association between the two which is as valid for 



