Full Idea
Quantity refers to nothing other than the parts of the thing quantified, together with their location or position, being extrinsically coordinated with each other.
Gist of Idea
Quantity is the quantified parts of a thing, plus location and coordination
Source
Peter John Olivi (Treatise on Quantity [1286], f. 49vb), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 14.1
Book Reference
Pasnau,Robert: 'Metaphysical Themes 1274-1671' [OUP 2011], p.281
A Reaction
I'm not sure I understand 'extrinsically'. Is there some external stretching force? God spends his time spreading out his stuff? It is nice that being spread out isn't taken for granted. We take much more for granted than they did. Motion, for example.