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Single Idea 13019

[filed under theme 4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets ]

Full Idea

The Iterative Conception (Zermelo 1930) says everything appears at some stage. Given two objects a and b, let A and B be the stages at which they first appear. Suppose B is after A. Then the pair set of a and b appears at the immediate stage after B.

Gist of Idea

The Iterative Conception says everything appears at a stage, derived from the preceding appearances

Source

Penelope Maddy (Believing the Axioms I [1988], §1.3)

Book Ref

-: 'Journal of Symbolic Logic' [-], p.485


A Reaction

Presumably this all happens in 'logical time' (a nice phrase I have just invented!). I suppose we might say that the existence of the paired set is 'forced' by the preceding sets. No transcendental inferences in this story?


The 11 ideas from 'Believing the Axioms I'

New axioms are being sought, to determine the size of the continuum [Maddy]
The Axiom of Extensionality seems to be analytic [Maddy]
Extensional sets are clearer, simpler, unique and expressive [Maddy]
The Iterative Conception says everything appears at a stage, derived from the preceding appearances [Maddy]
Limitation of Size is a vague intuition that over-large sets may generate paradoxes [Maddy]
The Axiom of Infinity states Cantor's breakthrough that launched modern mathematics [Maddy]
Infinite sets are essential for giving an account of the real numbers [Maddy]
The Power Set Axiom is needed for, and supported by, accounts of the continuum [Maddy]
Efforts to prove the Axiom of Choice have failed [Maddy]
Modern views say the Choice set exists, even if it can't be constructed [Maddy]
A large array of theorems depend on the Axiom of Choice [Maddy]