AN ESSAY ON 



those places, and the information from feeling, 

 that the objects which cause them are single. 

 What I shall say, therefore, upon his opinion, 

 will tend to show, that, admitting the fact re- 

 specting corresponding points to be true, his 

 explanation of it ought, however, to be rejected. 

 For, first, it may be observed, that, if we are 

 taught by feeling to see objects single, notwith- 

 standing a sensation in each eye, the informa- 

 tions of the former sense ought to be uniform, 

 or else one set of visual appearances would be 

 associated with different reports from feeling, 

 and no certain mark afforded us which of them 

 we should trust. Now Dr. Smith himself is 

 obliged to confess, that we sometimes feel dou- 

 ble, " as in the dark, when a button is pressed 

 with two opposite sides of two contiguous fin- 

 gers laid across ; for this reason, that those op- 

 posite sides of the fingers have never been used 

 to feel one but always' two things at a time*." 

 He adds, " We have learned, therefore, by ex- 

 perience of both senses compared together, to 

 make their informations consistent with each 

 other." Here, then, we find him to allow, that 



* Vol. I. p. 48. Dr. Smith, however, has, from the in- 

 fluence of system, I suppose, mistaken this fact; for the 

 button is felt double when pressed in the manner above 

 mentioned, though we should not be in the dark, and should 

 even see it to be single. 



