An Essay on the Signs of Ideas. 247 
Whether we have ideas of sensations re- 
ceived by the skin, seems to me still more 
likely to be determined in the negative. 
Of the sensations experienced in the other 
textures and organs, it is, I think, quite cer- 
tain that we never have ideas. 
On what circumstances it depends, that 
we have ideas of the sensations of some or- 
gans and textures, and not of those of others, 
is entirely unknown. 
Ideas, I may be allowed to add, succeed 
one another, in our consciousness, agreeably 
to certain laws, which are called the laws of 
association, and which may be reduced to 
these two:—1. Whatever ideas have previ- 
ously followed one another, will have a ten- 
dency to follow one another again in the same 
order; 2. Whatever ideas are in any degree 
similar will be more apt to succeed one ano- 
ther than those which have no similarity, 
Derangements of association, when remark- 
able, are called insanity. 
Sensations of emotion, are dinch feelings 
as are excited, not by the usual and appro- 
priate causes of simple sensations, nor yet by 
simple sensations themselves, but by ideas, 
or trains of ideas, and they differ from one 
another, according to the peculiar train from 
which each has arisen. They consist, some- 
