FACULTIES OF THE MIND. 294 
wolf uniting in bands in the chace,—and, while afraid of at- 
tacking men in company, appearing fearless of the resistance 
of a strageler. 
In our intercourse with the world, we are much guided 
by our ideas of personality. We recognise objects which 
we have formerly examined, and, convinced of their iden- 
tity, confidently expect them to be still possessed of the 
same qualities we formerly discovered them to be invested 
with. Ifa change has taken place in their appearance, we 
expect a corresponding change in their qualities. When 
we witness two individuals exhibiting similar characters, 
we expect to meet in both the same qualities. It is by 
means of this acquaintance with individuals, and this power 
of detecting resemblance or dissimilarity, that we obtain 
the greater part of our knowledge of ourselves and the 
world around us, and place confidence in the value of our 
systematical arrangements. But if much knowledge is thus 
gained, a fruitful source of error ts established by the em- 
ployment of what is termed Analogy. 
Analogy may be safely employed in the prosecution of 
knowledge or the business of life, were we to regard the 
probability of the truth of its deductions, to be directly as 
the resemblance of the condition of the objects compared. 
By not attending to this test of the value of a deduction 
from analogy, much error has been introduced into science, 
and a legitimate instrument of philosophical research per- 
verted and misapplied. In justification of the severity of 
our remark, we may here quote a few examples. 
It is well known, that the age of trees can be determined 
with considerable certainty, by counting the layers of wood; 
their number being, in general, equal to the years of 
growth. This particular character of ligneous stems has 
given rise to attempts to discover the age of other substan- 
ces which are composed of concentric layers. Thus, the 
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