Full Idea
Surfaces, lines and points are not, strictly speaking, parts of space at all, but just 'limits' of certain kinds, and as such 'abstract' entities.
Gist of Idea
Surfaces, lines and points are not, strictly speaking, parts of space, but 'limits', which are abstract
Source
E.J. Lowe (A Survey of Metaphysics [2002], p.254)
Book Reference
Lowe,E.J.: 'A Survey of Metaphysics' [OUP 2002], p.254
A Reaction
This is fairly crucial when dealing with Zeno's paradoxes. How many points in a line? How long to get through a point?