No further subdivision of the common intersection is possible by means of moments.

The 'all or none' principle holds.

This is not an _a priori_ truth but an empirical fact of nature.
It will be convenient to reserve the ordinary spatial terms 'plane,' 'straight line,' 'point' for the elements of the timeless space of a time-system.

Accordingly an instantaneous plane in the instantaneous space of a moment will be called a 'level,' an instantaneous straight line will be called a 'rect,' and an instantaneous point will be called a 'punct.' Thus a punct is the assemblage of abstractive elements which lie in each of four moments whose families have no special relations to each other.

Also if P be any moment, either every abstractive element belonging to a given punct lies in P, or no abstractive element of that punct lies in P.
Position is the quality which an abstractive element possesses in virtue of the moments in which it lies.