XXX INTRODUCTION. 



she has carried the others. The keenness of the scent 

 of the hound, and the discriminating nicety of the bee, 

 in opening sources of enjoyment merely physical, 

 would have degraded, instead of elevating us; by en- 

 grossing our time and ingenuity, in the development 

 of pleasures incompatible with our constitutions and 

 destinies. 



Man being thus constituted, it is worthy of inquiry 

 in what his life consists. According to the celebrated 

 Bichat, it is " the aggregate of those functions by 

 which death is resisted. For such, indeed, is the con- 

 dition on which we live, that every thing surrounding 

 us has a tendency to produce our dissolution, by the 

 affinities existing between their atoms, and the atoms 

 of which a living body is composed. It is plain, there- 

 fore, that the principle of life, like all other principles 

 in nature, incomprehensible in itself, must be- studied 

 by its phenomena."* 



There are two remarkable modifications of life : one 

 is common to the vegetable and to the animal, the other 

 is the exclusive attribute of the latter. Under the first 

 modification, are included assimilation and excretion, 

 which, though exercised under apparently different 

 circumstances in animals and in plants, are probably 

 essentially the same in both. This modification is 

 termed by Bichat, Organic Life. By the second mo- 

 dification of life, the animal has a more extended 

 sphere of existence than the vegetable, is put into a 

 certain relation with all the objects that surround him, 

 is made the inhabitant of the whole world, and not, 

 like the vegetable, confined for ever to the place of its 

 birth. By it the animal feels, and is conscious of ex- 

 ternal objects, reflects upon them, moves voluntarily,. 



* Recherches sur la vie et La Mort. 



