cH.ii.] PRINCIPAL GENERA OF EXISTING ANIMALS. 321 



with mind. We can only infer the true condition of animals, 

 in this respect, from their organisms and their acts. We have 

 conclusively shown, that animals unendowed with mind perform, 

 by the vis nervosa only, in the highest degree of completeness, 

 those acts (with certain exceptions) which are performed by 

 sentient animals. Consequently, nature was not obliged to 

 render all animals sentient, if she were willing to be satisfied with 

 those which could sufficiently perform the natural functions of 

 alimentation, defence, and propagation of the species, although 

 not capable of the more perfect acts of sentient animals. If, then, 

 there are animals defective in the higher order of passions, in 

 reason, and will ; animals, which do not possess the organ of the 

 conceptive force peculiar to sentient beings; whose whole life is so 

 uniform, simple, and unvaried, that they do not possess even the 

 vis nervosa, so perfectly as sentient animals possess it after de- 

 capitation ; animals, which can continue in life, almost as per- 

 fectly, when that is removed which is considered the machine (if 

 the phrase may be allowed) of the conceptive force, namely, the 

 entire head wherein their mind must dwell (621 — 624) as before; 

 we are necessarily led to the conclusion, that it has pleased 

 nature not to place a considerable portion of the animal creation 

 in closer connection with a thinking essence, or to endow it 

 uselessly with mind. Still it would be well to notice the op- 

 posing arguments, few of which, however, are of much weight. 



i. The objection that the definition of an animal includes the 

 idea of the existence of mind, has been answered already (622). 



ii. But it is advanced, " that all animals feel when they 

 receive external impressions, and since external sensations are 

 conceptions, they must therefore have mind.'^ To this we reply, 

 that we have no knowledge that they feel external impressions, 

 but only that the latter induce animal movements. It is 

 allowed, that all direct and incidental sentient actions of ex- 

 ternal sensations may be excited in animals endowed with 

 mind, by the vis nervosa of their external impressions, both 

 during Kfe and after decapitation (542 — 544) ; and, in fact, it 

 is more difficult to prove, that these movements are sentient 

 actions of the external sensations of the impressions, than that 

 they are nerve-actions of the impressions solely (582 — 588) . 



iii. It is also objected, that " many insects, worms, &c., 

 which must be considered unendowed with mind, have never- 



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