370 CLASS MAMMALIA. 



An organized body, whether animal or vegetable, exists 

 by the means of generation alone, and is thus distinguished 

 from an inorganized body, whose being may be said to be 

 fortuitous. The organized body must be kept alive, must 

 be fed from without, and must propagate ; and these pro- 

 cesses presuppose some original active agency, which 

 agency is the living principle,or nervous irritability, of phy- 

 siologists, the instinctive principle of metaphysicians, and 

 the involuntary corporeal impulse or mechanism, sometimes 

 called mechanical instinct, to which we allude. To enu- 

 merate the various mechanical actions which must be going 

 on unceasingly and unconsciously, in every organized body, 

 would exceed both our means and limits. Nutriment taken 

 in by the animal body at the mouth, and by the vegetable 

 at the root, is constantly undergoing a most complicated and 

 wonderful process : is first reduced to a fluid, purely sui 

 generis, is impelled and driven to every part of the little 

 world it is employed in sustaining; is again, by a sort of 

 chemical analysis, of which we have no notion, separated, 

 and while the essential parts are left by something like 

 precipitation, the useless residuum is passed off. What 

 power is it which impels these wonderful and complicated 

 actions, both in the vegetable and in the animal ? What, 

 but this living principle, this instinctive action, this invo- 

 luntary corporeal impulse, or mechanism, to which we allude. 

 To understand its nature however, we must first be divested 

 from the trammels of this material world, with which alone 

 we compare everything, and associate everything, and 

 with which, in fact, however connected, it bears no analogy. 



The third spring of action, in animals next below the 

 elevation of man, or voluntary mental impulse, we shall 

 venture, not indeed without authority, though with respect 

 for the contrary opinion of others, to consider as identified 

 with reason, limited indeed in its extent, and but very little 

 capable of improvement. 



