more from this thinker     |     more from this text


Single Idea 23623

[filed under theme 4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets ]

Full Idea

Predicativists doubt the existence of sets with no predicative definition.

Gist of Idea

Predicativism says only predicated sets exist

Source

Keith Hossack (Knowledge and the Philosophy of Number [2020], 02.3)

Book Ref

Hossack, Keith: 'Knowledge and the Philosophy of Number' [Routledge 2021], p.26


A Reaction

This would imply that sets which encounter paradoxes when they try to be predicative do not therefore exist. Surely you can have a set of random objects which don't fall under a single predicate?


The 9 ideas with the same theme [sets as defined by absolutely any concept]:

Russell invented the naïve set theory usually attributed to Cantor [Russell, by Lavine]
The set scheme discredited by paradoxes is actually the most natural one [Quine]
Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos]
Naïve set theory has trouble with comprehension, the claim that every predicate has an extension [Hart,WD]
The paradoxes are only a problem for Frege; Cantor didn't assume every condition determines a set [Burgess/Rosen]
Naïve set theory assumed that there is a set for every condition [Brown,JR]
Nowadays conditions are only defined on existing sets [Brown,JR]
Naïve set theory says any formula defines a set, and coextensive sets are identical [Linnebo]
Predicativism says only predicated sets exist [Hossack]