26 INTRODUCTION. 
The modifications experienced by the medullary masses 
leave impressions there which are reproduced, and thus re- 
cal to the mind images and ideas; this is memory, a corporeal 
faculty that varies greatly, according to the age and health of 
the animal. 
Similar ideas, or such as have been acquired at the same 
time, recal each other; this is the association of ideas. ‘The 
order, extent and quickness of this association constitute the 
perfection of memory. 
Every object presents itself to the memory with all its quali- 
ties or with all its accessary ideas. 
Intelligence has the power of separating these accessary 
ideas of objects, and of combining those that are alike in 
several different objects under a general idea; the object of 
which no where really exists, nor presents itself per se—this 
is abstraction. 
Every sensation being more or less agreeable or disagree- 
able, experience and repeated essays soon show what move- 
ments are required to procure the one and avoid the other; 
and with respect to this, the intelligence abstracts itself from 
the general rules to direct the will. 
An agreeable sensation being liable to consequences that are 
not so, and vice versa, the subsequent sensations become asso- 
ciated with the idea of the primitive one, and modify the 
general rules framed by intelligence—this is prudence. 
From the application of these rules to general ideas, result 
certain formule, which are afterwards easily adapted to par- 
ticular cases—this is called reasoning. 
A lively remembrance of primitive and associated sensations, 
and of the impressions of pleasure or pain that belong to them, 
constitutes imagination. 
One privileged being, man, has the faculty of associating 
his general ideas with particular images more or less arbitrary, 
easily impressed upon the memory, and which serve to recal 
the general ideas they represent. These associated images 
are styled signs; their assemblage 1 is a language. When the 
language is composed of images: ‘that relate to the sense. of 
hearing or of sownds, it is termed speech, and when relative 
em at” 
