i86 THEPHILOSOPHY 



which fome men feel in the dark, and of thofe ghofts and horrible 

 figures which fo many people pofitively affert they have feen in the 

 night. Such figures are commonly faid to exift in the imagination 

 only ; but they often have a real exiftence in the eye ; for, when 

 we have no other mode of recognifing unknown objedts but by the 

 angle they form in the eye, their magnitude is uniformly augmented 

 in proportion to their vicinity. If an objed, at the diftance of twenty 

 or thirty pace&, appears to be only a few feet high, its height, when 

 viewed within two or three feet of the eye, will feem to be many 

 fathoms. Objedts, in this fituation, muft excite terror and aftonifti- 

 ment in the fpeftator, till he approaches and recognifes them by ac- 

 tual feeling ; for the moment a man examines an objedl properly, 

 the gigantic figure it affumed in the eye inftantly vanifhes, and its 

 apparent magnitude is reduced to its real dimenfions. But if, in- 

 ftead of approaching an objedt of this kind, the fpedator flies from it, 

 he retains the idea which the image of it formed in his eye, and he 

 may aflSrm with truth, that he beheld an objeft terrible in its afpedl, 

 and enormous in its fize. Hence the notion of fpedres, and of hor- 

 rible figures, is founded In nature, and depends not folely on ima- 

 gination. 



When we have no idea of the diftance of objeds by a previous 

 knowledge of the fpace between them and the eye, we try to judge 

 of their magnitudes by recognifing their figures. But, when their 

 figures are not diftinguifhable, we perceive thofe which are moft: 

 brilliant in colour to be neareft, and thofe that are moft obfcure to 

 be at the greateft diftance. From this mode of judging many de- 

 ceptions originate. When a number of objeds are placed in a right 

 line, as lamps in a long ftreet, we cannot judge of their proximity 

 or remotenefs but by the different quantities of light they tranfmit 

 to the eye. Of courfe, if the lamps neareft the eye happen to be 



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