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Single Idea 13127

[filed under theme 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

Source

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

Book Ref

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.

The 21 ideas with the same theme [general ideas about how to group what exists]:

16661 There are two sorts of category - referring to things, and to circumstances of things [Boethius]
21448 Categories are general concepts of objects, which determine the way in which they are experienced [Kant]
5554 Categories are necessary, so can't be implanted in us to agree with natural laws [Kant]
22078 Even simple propositions about sensations are filled with categories [Hegel]
15634 Thought about particulars is done entirely through categories [Hegel]
21920 No need for a priori categories, since sufficient reason shows the interrelations [Schopenhauer, by Lewis,PB]
16961 In formal terms, a category is the range of some style of variables [Quine]
13127 Categories can't overlap; they are either disjoint, or inclusive [Sommers, by Westerhoff]
13403 The category of Venus is not 'object', or even 'planet', but a particular class of good-sized object [Jubien]
17377 All descriptive language is classificatory [Dupré]
8283 Ontological categories are not natural kinds: the latter can only be distinguished using the former [Lowe]
13118 Categories are base-sets which are used to construct states of affairs [Westerhoff]
13117 How far down before we are too specialised to have a category? [Westerhoff]
13116 Maybe objects in the same category have the same criteria of identity [Westerhoff]
13124 Categories can be ordered by both containment and generality [Westerhoff]
13125 Categories are held to explain why some substitutions give falsehood, and others meaninglessness [Westerhoff]
13126 Categories systematize our intuitions about generality, substitutability, and identity [Westerhoff]
13130 Categories as generalities don't give a criterion for a low-level cut-off point [Westerhoff]
10496 Monothetic categories have fixed defining features, and polythetic categories do not [Ellen]
10497 In symbolic classification, the categories are linked to rules [Ellen]
18564 Do categories store causal knowledge, or typical properties, or knowledge of individuals? [Machery]