INTRODUCTION. Xili 
infinite spirit as the source of all finitudes, instead 
of compelling it to rest on an unfounded imagina- 
tion that the particles of matter had other than 
their known properties and that these were sufficient 
for the evolution of consciousness. 
As to the exact position of the mind in relation 
to the chain of physical changes in the body, we 
may in the future learn more about it than we 
know at present, but, meanwhile, it is quite certain 
that mental action is not in quantitative relation 
to the preceding external influences applied to the 
organs of sense. If a servant whispers in your 
ear that there are robbers in the house, there will 
be caused much less vibration of the drum of your 
ear and consequent action of the auditory nerve 
than by the loud ringing of a dinner bell ; but there 
will possibly result very much greater mental dis- 
turbance. The stimuli in both cases would be 
applied to the same nerves ; and no physical theory 
can represent it as possible that the channels 
taken in the brain by the irritation conveyed along 
the nerves would vary according to the meaning of 
the sounds. It is plain therefore that the physical 
stimulant in sensation does not lie in the same re- 
lation to the mental changes immediately following, 
as does the charge exploded in a gun to the flight 
of the bullet. The vibration in the ear produces 
change in the nerves proportionate to its amount : 
and science does not know how the last of these 
