iS2 THEPHILOSOPHY 



The firft and greateft error In vifion, in the opinion of many au- 

 thors, arifes from the inverted reprefentation of obje£ls upon the re- 

 tina ; and they maintain, that, till children learn the real pofitlon of 

 bodies by the fenfe of feeling, they fee every objeft inverted. But 

 new born animals, vphether of the human or brute fpecies, fee ob- 

 jeds, not inverted, but in their real pofuions, independently of all 

 experience, or of any opportunity of rectifying the fuppofed illufion 

 by the fenfe of touch. Animals fee objeds in their real pofition by a 

 law of Nature, and by the inftrumentality of the eye and optic nerve. 

 Were it not a law of Nature, or of the conftitution of animals, to fee 

 objeds eredt, though their images be inverted on the retina, an in- 

 verted objeft could not poffibly appear inverted; for, in this cafe, 

 we {hould not be obliged to have recourfe to experience, or to the 

 fenfe of feeling. Befides, it is an eftabiifhed fad, that blind men, 

 who had been reftored to fight by chirurgical operations, inftantly 

 faw objeds in their real pofition *. There is no relation to the 

 principles of optics, in tlie fenfation of feeling, by which an image, 

 painted by rays of light on foft white nervous terminations, is con- 

 veyed through a moft opaque body, in a long courfe of perfed dark- 

 nefs, to the brain. Indeed, the fenfe by which the perceiving nerves 

 of any kind are affefted, is not an image or idea' of the objed. The 

 idea of rednefs has nothing in common with the lead refrangible 

 portions of light feparated from the other fix coloured rays of which 

 white light is compofed. The pain of burning reprefents not to the 

 mind any thing of that fwift and fubtle matter by which the ner- 

 vous threads are broken or deftroyed. There is nothing in the idea 

 of a (harp found, from a cord of a certain length, which can inform 

 the mind that this cord vibrates 2000 times in a fecond f. 



Another 



Haller. PhyCol. torn. 2. pag. 8 



f For a more ample difcuflion of this point, fee Haller. Phyfiol. torn. 2. j — and 

 Dr Reld's Inquiry. 



