8 THEORETICAL BIOLOGY 



signs as material, " motion " as their sensation-form, because 

 within it every possible direction is contained. 



THE PLANES OF DIRECTION 



When we close our eyes and picture what-lies-outside-our- 

 selves as filled with series of direction-signs, we become aware 

 that the series are arranged not merely with relation to one 

 another, but that each series occupies a fixed place. This is 

 surprising, since our inner direction-signs (we are dealing 

 only with these here) are quite free from local signs, and 

 what-lies-outside-ourselves has in itself no places whatsoever. 



How comes it then that we are nevertheless able to assign 

 its fixed place to every direction-sign ? On closer inspection 

 it appears that we are able to split up what-lies-outside- 

 ourselves into three pairs of halves — (i) right and left, (2) 

 above and below, (3) before and behind. We intersect what- 

 lies-outside-ourselves by means of three bisecting planes, 

 which cross one another in front of our heads. The attentive 

 observer will notice that, while what-lies-outside-ourselves 

 remains at rest, the system of the three planes shifts as 

 the head moves. 



As a magnet arranges iron-filings, so the direction-signs 

 of the same kind place themselves on the bisecting plane that 

 belongs to them, along the lines of this marvellous magnet. 

 And thus a kind of three-dimensional canvas is formed, in 

 which the movements actually performed appear like threads 

 of coloured wool. 



It is only by the insertion of the three planes of direction 

 that what-lies-outside-ourselves becomes " space " as we know 

 it and make use of it. It is nothing but a pure form, ready to 

 receive aU our sense-qualities, and these become linked up 

 with it directly or indirectly. Space is a perfect unity — a self- 



