260 Luck, or Cunning ? 
attendant. It is no more like these than, say, a stone is 
like the individual characters, written or spoken, that form 
the word “ stone,” or than these last are, in sound, like the 
word ‘stone ”’ itself, whereby the idea of a stone is so 
immediately and vividly presented to us. True, this does 
not involve that our idea shall not resemble the object that 
gave rise to it, any more than the fact that a looking-glass 
bears no resemblance to the things reflected in it involves 
that the reflection shall not resemble the things reflected ; 
the shifting nature, however, of our ideas and conceptions 
is enough to show that they must be symbolical, and con- 
ditioned by changes going on within ourselves as much as 
by those outside us; and if, going behind the ideas 
which suffice for daily use, we extend our inquiries in the 
direction of the reality underlying our conception, we find 
reason to think that the brain-motions which attend our 
conception correspond with exciting motions in the object 
that occasions it, and that these, rather than anything 
resembling our conception itself, should be regarded as the 
reality. 
This leads to a third matter, on which I can only touch 
with extreme brevity. 
Different modes of motion have long been known as the 
causes of our different colour perceptions, or at any rate 
as associated therewith, and of late years, more especially 
since the promulgation of Newlands’* law, it has been 
perceived that what we call the kinds or properties of 
matter are not less conditioned by motion than colour is. 
The substance or essence of unconditioned matter, as apart 
from the relations between its various states (which we 
believe to be its various conditions of motion) must remain 
for ever unknown to us, for it is only the relations between 
the conditions of the underlying substance that we cognise 
at all, and where there are no conditions, there is nothing 
* Sometimes called Mendelejeft’s (see ‘‘ Monthly Journal of 
Science,” April, 1884). 
