PHYSIOLOGY OF CONSCIOUSNESS 233 



which prevent further analysis by inhibiting the opening 

 of fresh neuronal paths. This is a phenomenon known 

 to psychiatrists as " resistance." But though " re- 

 sistance " to fresh stimulation taught in the shape of 

 combinations of word signs or sound symbols is frequently 

 accompanied with dislike of the " idea," by which we 

 must understand a new set of reactions, it may be with- 

 out any such dislike, and may represent only a temporary 

 incapacity, under the weak stimulation of an inadequate 

 verbal presentment of convincing analysis, to establish 

 new nervous connections. The difficulties of dealing 

 satisfactorily to all with such a subject, and the right 

 way to attempt it, may be suggested by considering that 

 the very word " convincing " just used is obviously 

 shorthand or a symbol for the reflex opening of fresh 

 neuronal paths which offer great synaptic resistance. 

 Such views explain the physiological reasons that it is so 

 difficult to convince the old. In them synaptic resistance 

 tends to become synaptic block. The opposed pheno- 

 menon is observed in fixed ideas, and in mania, where 

 over certain tracts there are what may be called " fused " 

 synapses in which the gemmules for pathological reasons 

 do not retract until exhaustion occurs. I suggest, then, 

 that when a man like Huxley, a very powerful stimulator, 

 asserts consciousness to be a mystery, such an asser- 

 tion is likely to inhibit speculation on the part of others, 

 such inhibition taking the form of saying, " if a brain 

 like Huxley's found it so, is it likely that I should ever 

 get to understand it ? " It must, however, be remembered 

 that the whole history of science might be mapped out 

 in a series of statements as too " impenetrable mysteries ' 

 which have proved themselves capable of easy solution. 

 I remember being much struck by the objection of an 



