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2. Reason / D. Definition / 8. Impredicative Definition

[definition that doesn't introduce a new concept]

7 ideas
A defined name should not appear in the definition [Hobbes]
Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? [Lavine on Zermelo]
Impredicative Definitions refer to the totality to which the object itself belongs [Gödel]
Impredicative definitions are wrong, because they change the set that is being defined? [Bostock]
Impredicative definitions quantify over the thing being defined [George/Velleman]
An 'impredicative' definition seems circular, because it uses the term being defined [Friend]
Predicative definitions only refer to entities outside the defined collection [Horsten]