50 THEORETICAL BIOLOGY 



description of sounds as " high " and " low " bears this 

 out. 



In order to make very vivid what is meant by existence in 

 subjective space, let us think of ourselves as condemned to 

 move by swimming about in water, without eyes or organs of 

 touch. In such a case, we should learn nothing from our 

 swimming movements beyond the changing claims of our 

 subjective direction-signs ; we should learn absolutely nothing 

 about forward movement in space. 



Now if we imagine ourselves as having an eye that can 

 release colour-sensations but not local signs, still that would 

 alter nothing with regard to subjective space ; the sensations 

 of red, green, blue and yellow would indeed arise, but the 

 colours would remain properties of our subject, and the inner 

 world of the subject means likewise the world as a whole. 

 We ourselves would be emitting simultaneously sound and 

 colour and filling the whole of space with our person. It 

 would be impossible to draw a distinction between thoughts 

 and feelings, on the one hand, and sense-perceptions on the 

 other, because the latter could not become properties of 

 objects. We should then be solipsists, in the real sense of 

 the word. 



As soon as local signs appear, the world is transformed 

 in a flash ; space acquires places to which colours can attach 

 themselves, and from the sensations of colour develop coloured 

 surfaces. No longer do colours appear and then disappear, as 

 our eye roams to and fro. The red circle over there remains 

 red, even if we are no longer looking directly at it. And by 

 so doing, it has acquired an objective existence independent of 

 the optical activity of the subject ; on the other hand, it 

 remains dependent on its position in a space that has now 

 become objective. 



The same thing happens with the other sense-qualities. 

 The red circle that we touch remains hard, even when we no 



