FACULTIES OF THE MIND. 22? 



wolf uniting in bands in the chace, and, while afraid of at- 

 tacking men in company, appearing fearless of the resistance 

 of a straggler. 



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. If a 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 is 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 

 tJie 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 



