ABSTRACT
THE relation of order exemplified by three elements arranged in a series ABC also entails a specific relationship expressed by the word ‘between’. Thus B is ‘between’ A and C, and at the same time ‘between’ C and A. In Chapter III we saw how this relationship, whose invariance remains a mystery to children who have not yet learned to reverse a series, evolves concurrently with the notion of order itself. 2 Now the relation ‘between’ is one particular instance of the more general relationships of ‘surrounding’. These are, of course, elementary spatial relationships, just as much as proximity, separation or order. Indeed, as regards the construction of space, they are even more important, since it is most probably these relationships which lead the child by the most direct route, to differentiate and build up the three initial topological dimensions.
