sensation: 27 



ered with snow and lighted by brilliant sunshine ; whereas 

 what he really saw Avas the white snow on trees near by, 

 lying in shadow]. * 



Such a mistake as this is undoubtedly of psychological 

 origin. It is a wrong classification of the appearances, 

 due to the arousal of intricate processes of association^ 

 amongst which is the suggestion of a different hue from 

 that really before the eyes. In the ensuing chapters such 

 illusions as this will be treated of in considerable detail. 

 But it is a mistake to interpret the simpler cases of con- 

 trast in the light of such illusions as these. These illu- 

 sions can be rectified in an instant, and we then wonder 

 how they could have been. They come from insufiicient 

 attention, or from the fact that the impression which we 

 get is a sign of more than one possible object, and can be 

 interpreted in either way. In none of these points do they 

 resemble simple color-contrast, which unquestionably is a 

 •phenomenon of sensation immediately aroused. 



I have dwelt upon the facts of color-contrast at such 

 great length because they form so good a text to comment 

 on in my struggle against the view that sensations are im- 

 mutable jisychic things which coexist with higher mental 

 functions. Both sensationalists and intellectualists agree 

 that such sensations exist. They ftise, say the pure sen- 

 sationalists, and make the higher mental function ; they 

 are combined by activity of the Thinking Principle, say the 

 intellectualists. I mj^self have contended that they do not 

 exist in or alongside of the higher mental function when 

 that exists. The things which arouse them exist ; and the 

 higher mental function also knows these same things. But 

 Just as its knowledge of the things supersedes and displaces 

 their knowledge, so it supersedes and displaces them, 

 when it comes, being as much as they are a direct result- 

 ant of whatever momentary brain-conditions may obtain. 

 The psychological theory of contrast, on the other hand, 

 holds the sensations still to exist in themselves unchanged 

 before the mind, whilst the 'relating activity' of the latter 



* Mr. Delabarre's contribution ends here. 



