Full Idea
The distinction of abstract and concrete is one of kind and not degree.
Gist of Idea
Abstract/concrete is a distinction of kind, not degree
Source
JP Burgess / G Rosen (A Subject with No Object [1997], I.A.1.a)
Book Reference
Burgess,J/Rosen,G: 'A Subject with No Object' [OUP 1997], p.14
A Reaction
I think I must agree with this. If there is a borderline, it would be in particulars that seem to have an abstract aspect to them. A horse involves the abstraction of being a horse, and it involves be one horse.
Related Idea
Idea 9884 The distinction of concrete/abstract, or actual/non-actual, is a scale, not a dichotomy [Dummett]