Sect. III. 6. 4. THE RETINA. iq 



flump with a fimilar degree or kind of pain, the ideas of the 

 ihape, place, or folidity of the loft limb, return by affochtion ; 

 as thefe ideas belong to the organs of fight and touch, on 

 which they were firft excited. 



4. If you wonder what organs of fenfe can be excited into 

 motion, when you call up the ideas of wifdom or benevolence, 

 which Mr. Locke has termed abftracted ideas ; I afk you by 

 what organs of fenfe you firft became acquainted with thefe 

 ideas ? And the anfwer will be reciprocal ; for it is certain that 

 all our ideas were originally acquired by our organs of fenfe - ? 

 for whatever excites our perception rnuft be external to the or- 

 gan that perceives it, and we have no other inlets to knowledge 

 but by our perceptions : as will be further explained in Section 

 XIV. and XV. on the Productions and ClaiTes of ideas. 



VII. If our recollection or imagination be not a repetition of 

 animal movements, I afk, in my turn, What is it ? You tell me 

 it confifts of images or pictures of things. Where is this ex- 

 tenfive canvas hung up ? or where are the numerous receptacles 

 in which thofe are depofited ? or to what elfe in the animal 

 fyftem have they any fimilitude ? 



That pleafing picture of objects, reprefented in miniature on 

 the retina of the eye, feems to have given rife to this illufive or- 

 atory ! It was forgot that this representation belongs rather to 

 the laws of light, than to thofe of life ; and may with equal ele- 

 gance be feen in the camera obfcura as in the eye ; and that the 

 picture vanifhes for ever, when the object is withdrawn. 



s;ect. 



