SPACE 15 



external experience. It is just these qualities, and more 

 especially the direction-signs, that have space as their neces- 

 sary form. On that account, we can develop the whole theory 

 of space without the assistance of external experience ; and 

 since all the other qualities come directly or indirectly into 

 relation with space, we may say that space precedes all 

 experience as the form of intuition common to all experience, 

 and that the laws regulating it, which we investigate through 

 the inner experiences of our own movements, were a priori 

 there in their entirety. 



But with space, not merely do its laws precede external 

 experience, but so also does the science of these laws. This 

 explains the exceptional part played by the figures in plane 

 geometry. These figures that we draw are not outlines of 

 objects, but imperfect symbols of our own movements ; by 

 the attempt to commit to paper by means of lines the series 

 of direction-signs, we study the relation of these movements to 

 one another. 



It is clear that plane geometry precedes external experi- 

 ence, but equally clear that plane geometry is a creation of 

 internal experience. We should be led into serious error if 

 we were to assume that somehow, by means of memory-signs 

 in the imagination, we could establish a science that would 

 inform us as to what actually happens. An actual phenomenon, 

 whether external or internal, can only be recognised in itself. 



While it is true that there can be an idea of space into 

 which the memory-signs can be thrown, yet space itself is 

 not an idea. Space is an essential component of our organisa- 

 tion, and, as such, an actual law of nature, valid subjectively 

 as well as objectively. 



In order to give us some insight into our own organisation, 

 Kant made apperception the central point of his doctrine. 

 Apperception is the activity lying at the root of all perception. 

 Only when it is in action can we learn anything about the 



