THE VALUE OF SCIENCE 407 



But then we may ask ourselves if the relative position of an object 

 with regard to other objects has changed or not, and first whether the 

 relative position of this object with regard to our body has changed. 

 If the impressions this object makes upon us have not changed, we shall 

 be inclined to judge that neither has this relative position changed; 

 if they have changed, we shall judge that this object has changed either 

 in state or in relative position. It remains to decide which of the two. 

 I have explained in ' Science and Hypothesis ' how we have been led 

 to distinguish the changes of position. Moreover, I shall return to 

 that further on. We come to know, therefore, whether the relative 

 position of an object with regard to our body has or has not remained 

 the same. 



If now we see that two objects have retained their relative position 

 with regard to our body, we conclude that the relative position of these 

 two objects with regard to one another has not changed; but we reach 

 this conclusion only by indirect reasoning. The only thing that we 

 know directly is the relative position of the objects with regard to 

 our body. A fortiori it is only by indirect reasoning that we think 

 we know (and, moreover, this belief is delusive) whether the absolute 

 position of the object has changed. 



In a . word, the system of coordinate axes to which we naturally 

 refer all exterior objects is a system of axes invariably bound to our 

 body, and carried around with us. 



It is impossible to represent to oneself absolute space; when I try 

 to represent to myself simultaneously objects and myself in motion in 

 absolute space, in reality I represent to myself my own self motionless 

 and seeing move around me different objects and a man that is exterior 

 to me, but that I convene to call me. 



Will the difficulty be solved if we agree to refer everything to these 

 axes bound to our body? Shall we know then what is a point thus 

 defined by its relative position with regard to ourselves? Many per- 

 sons will answer yes and will say that they ' localize ' exterior objects. 



What does this mean? To localize an object simply means to 

 represent to oneself the movements that would be necessary to reach it. 

 I will explain myself. It is not a question of representing the move- 

 ments themselves in space, but solely of representing to oneself the 

 muscular sensations which accompany these movements and which do 

 not presuppose the preexistence of the notion of space. 



If we suppose two different objects which successively occupy the 

 same relative position with regard to ourselves, the impressions that 

 these two objects make upon us will be very different; if we localize 

 them at the same point, this is simply because it is necessary to make 



