Ideas from 'Difficulties of Transfinite Numbers and Types' by Bertrand Russell [1905], by Theme Structure

[found in 'Essays in Analysis' by Russell,Bertrand (ed/tr Lackey,Douglas) [George Braziller 1973,0-8076-0699-5]].

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6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
We need rules for deciding which norms are predicative (unless none of them are)
                        Full Idea: We need rules for deciding what norms are predicative and what are not, unless we adopt the view (which has much to recommend it) that no norms are predicative. ...[146] A predative propositional function is one which determines a class.
                        From: Bertrand Russell (Difficulties of Transfinite Numbers and Types [1905], p.141)
                        A reaction: He is referring to his 'no class' theory, which he favoured at that time.
'Predicative' norms are those which define a class
                        Full Idea: Norms (containing one variable) which do not define classes I propose to call 'non-predicative'; those which do define classes I shall call 'predicative'.
                        From: Bertrand Russell (Difficulties of Transfinite Numbers and Types [1905], p.141)