Single Idea 13127

[catalogued under 7. Existence / E. Categories / 1. Categories]

Full Idea

Fred Sommers, in his treatment of types, says that two ontological categories cannot overlap; they are either disjoint, or one properly includes the other. This is sometimes referred to as Sommers' Law.

Gist of Idea

Categories can't overlap; they are either disjoint, or inclusive


report of Fred Sommers (Types and Ontology [1963], p.355) by Jan Westerhoff - Ontological Categories 24

Book Reference

Westerhoff,Jan: 'Ontological Categories' [OUP 2005], p.57

A Reaction

The 'types', of course, go back to Bertrand Russell's theory of types, which is important in discussions of ontological categories. Carnap pursued it, trying to derive ontological categories from grammatical categories. 85% agree with Sommers.