AND ANIMAL LIFE. 327 



ever laws or principles maybe advanced to explain 

 one class of phenomena will apply equally well 

 to another, whose only difference lies in the de- 

 gree of the cause. 



CCCLXXVIII. One part of the philosophical 

 world is disposed to regard mind as an immater- 

 rial principle, independent of the direct control 

 of organization ; another would seem to measure 

 its profundity, or estimate its limits, by the quan- 

 tity of matter presented to the eye. In subjects 

 of this kind it is difficult to make even an ap- 

 proximation to truth, as the phenomena of which 

 we treat are inexplicable on any known law ? and 

 are too mysterious to be fathomed by the facul- 

 ties of man, in a manner sufficiently precise to 

 enable him to refer them to certain well esta- 

 blished principles of the mental constitution. 



CCCLXXIX. Effect and cause in the animal 

 economy cannot be compared to those arising 

 from ordinary physical adaptations. In the lat- 

 ter we have a clear and distinct idea of the rela- 

 tion existing between the two ; but in the former 

 the conception is indefinite and inconclusive, as 

 a variety of causes predispose to produce one 

 great and evident result, the nature and opera- 

 tion of which are not understood : or if one agent 

 be considered the efficient cause, our knowledge 

 even of this will necessarily be confined to its 

 most obvious influence, which will give us 

 no insight whatever into its own nature or 



