Single Idea 23457

[catalogued under 6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory]

Full Idea

Russell's theory of types meant that features common to different levels of the hierarchy became uncapturable (since any attempt to capture them would involve a predicate which disobeyed the hierarchy restrictions).

Gist of Idea

Type theory cannot identify features across levels (because such predicates break the rules)

Source

comment on Bertrand Russell (The Theory of Logical Types [1910]) by Michael Morris - Guidebook to Wittgenstein's Tractatus 2H

Book Reference

Morris,Michael: 'Guidebook to Wittgenstein's Tractatus' [Routledge 2008], p.112


A Reaction

I'm not clear whether this is the main reason why type theory was abandoned. Ramsey was an important critic.