388 THE HARMONIES OF NATURE. 



But by the wisdom of Providence the optic nerve can only 

 see, the auditive nerve only hear, the sensitive nerve only feel, 

 the olfactory nerve only smell, the gustatorial nerve only taste, 

 the motile nerve only move ; and thus as each messenger has 

 only one thing to do, he cannot possibly interfere with the 

 work of his neighbour, and all goes on in the most beautiful 

 order. 



Every nerve of our body is ultimately connected with the 

 brain, but not every nerve obeys its mandates, or communicates 

 to it distinct sensations. For all the vegetative functions of our 

 body, such as the digestive process, the circulation of the blood, 

 the secretions of the glands, are under the control of a peculiar 

 system of nerves, which, though connected with the brain, is in 

 a great measure independent of that central organ, and executes 

 its highly important task without our feeling it, or without our 

 being able to control its execution. 



Thus, as long as we are in health, our digestion goes on with- 

 out our being aware of it; we cannot bid our heart to stand 

 still ; we breathe without paying any attention to the respiratory 

 process ; the liver and the kidneys secrete without our perceiving 

 their activity in the least. This is evidently a most bene- 

 ficial arrangement, for how could our mind have found time 

 or repose for reflection and mental improvement how could 

 it properly have fixed its attention on the outer world, if 

 the brain, besides its actual tasks, had also been burdened with 

 the direction of our internal economy ? 



But as soon as our organs become affected with disease, then 

 the slumbering sympathies of our brain are called forth ; then 

 sensations of pain, awakening in parts of whose existence we 

 have but a dim feeling, inform us that the wonderful mechanism 

 of our body is out of order, and claims repose or medical assist- 

 ance. 



In spite of his vast mental superiority, man would have con- 

 stantly remained a most helpless and miserable creature if his 

 limbs, like those of the animals, had been merely made to serve 

 for motion, for climbing, or digging, or as offensive and defen- 

 sive weapons. But Providence, which gave man an intelligence 

 befitting him to be the master of the earth, could not possibly 

 have left him without the mechanical means necessary for 

 asserting his dominion ; and thus the anterior extremities, which 



