more from David M. Armstrong

### Single Idea 8537

#### [catalogued under 8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes]

Full Idea

Exact similarity is a symmetrical and transitive relation. (Less than exact similarity is not transitive, even for tropes). So the relation of exact similarity is an equivalence relation, partitioning the field of tropes into equivalence classes.

Gist of Idea

Tropes fall into classes, because exact similarity is symmetrical and transitive

Source

David M. Armstrong (Properties [1992], §2)

Book Reference

'Properties', ed/tr. Mellor,D.H. /Oliver,A [OUP 1997], p.168

A Reaction

Armstrong goes on the explore the difficulties for trope theory of less than exact similarity, which is a very good line of discussion. Unfortunately it is a huge problem for everyone, apart from the austere nominalist.