104 SCIENCE AND METHOD. 



assistance should meet the danger without mis- 

 carrying. 



When a frog's head has been cut off, and a drop of 

 acid is placed at some point on its skin, it tries 

 to rub off the acid with the nearest foot ; and if that 

 foot is cut off, it removes it with the other foot. Here 

 we have, clearly, that double parry I spoke of just now, 

 making it possible to oppose an evil by a second 

 remedy if the first fails. It is this multiplicity of 

 parries, and the resulting co-ordination, that is space. 



We see to what depths of unconsciousness we have 

 to descend to find the first traces of these spacial 

 associations, since the lowest parts of the nervous 

 system alone come into play. Once we have rea- 

 lized this, how can we be astonished at the resistance 

 we oppose to any attempt to dissociate what has been 

 so long associated ? Now, it is this very resistance 

 that we call the evidence of the truths of geometry. 

 This evidence is nothing else than the repugnance we 

 feel at breaking with very old habits with which we 

 have always got on very well. 



III. 



The space thus created is only a small space that 

 does not extend beyond what my arm can reach, 

 and the intervention of memory is necessary to set 

 back its limits. There are points that will always 

 remain out of my reach, whatever effort I may make 

 to stretch out my hand to them. If I were attached 

 to the ground, like a sea-polype, for instance, which 

 can only extend its tentacles, all these points would 

 be outside space, since the sensations we might 

 experience from the action of bodies placed there 



