12 THE AIM AND ACHIEVEMENTS OF SCIENTIFIC METHOD. 



reinstate the original sensible appearance by voluntary move- 

 ment.* 



It is true that a certain amount of difficulty is presented 

 by commonly occurring cases in which the plain man's lack of 

 interest in analysis leads him into apparent inconsistencies. 

 Thus when it is said of a plate in a certain position that 

 although it " looks " elliptical it is " really " circular, or of two 

 coloured materials that though they " appear " not to match 

 (by gaslight) they " really " do so ; or, again, that the table- 

 cloth which (in the dusk) " looks " black is " really " red ; the 

 well-known explanation that the word " really " refers here to- 

 assumed normal or standard conditions of perception is too 

 often taken as carrying the further implication that none of 

 the qualifications are Objective. In the case of the change 

 of shape this destructive suggestion is successfully resisted by 

 " everyone except a philosopher." Since the various shapes 

 are so completely under our control and can be made to melt 

 continuously into one another, we have no difficulty in 

 admitting that they all are simply different representations of 

 the same thing which actually is round, or elliptical, with an 

 endless succession of eccentricities, according to the way in 

 which it is looked at. Now the " plain man " will often make 

 similar statements in the other cases : he will say naively that 

 the materials which "are" of the same colour at noon "are'* 

 differently coloured by gaslight ; that the tablecloth which 

 " is " red in the daytime " is " black in the late twilight, and 

 this view of the matter is, I believe, the one which the " plain 

 man " would stand by if he were challenged ; while he would 

 be willing to admit the conventional character of the former 

 statements. Further, it is only (I submit) in the light of 

 special scientific attempts to " explain " these different mani- 

 festations of the same thing that it becomes regarded as 



* PoincarS, Science et Hypothese, p. 76. La Valeur de la Science, 

 pp. 82 et seq. 



