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Single Idea 18185

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory ]

Full Idea

The single unified area of set theory provides a court of final appeal for questions of mathematical existence and proof.

Gist of Idea

Unified set theory gives a final court of appeal for mathematics

Source

Penelope Maddy (Naturalism in Mathematics [1997], I.2)

Book Ref

Maddy,Penelope: 'Naturalism in Mathematics' [OUP 2000], p.26


A Reaction

Maddy's third benefit of set theory. 'Existence' means being modellable in sets, and 'proof' means being derivable from the axioms. The slightly ad hoc character of the axioms makes this a weaker defence.

Related Ideas

Idea 18183 Set theory brings mathematics into one arena, where interrelations become clearer [Maddy]

Idea 18184 Making set theory foundational to mathematics leads to very fruitful axioms [Maddy]


The 26 ideas from 'Naturalism in Mathematics'

The extension of concepts is not important to me [Maddy]
Mathematics rests on the logic of proofs, and on the set theoretic axioms [Maddy]
We can get arithmetic directly from HP; Law V was used to get HP from the definition of number [Maddy]
Frege solves the Caesar problem by explicitly defining each number [Maddy]
For any cardinal there is always a larger one (so there is no set of all sets) [Maddy]
Axiom of Reducibility: propositional functions are extensionally predicative [Maddy]
'Propositional functions' are propositions with a variable as subject or predicate [Maddy]
Infinity has degrees, and large cardinals are the heart of set theory [Maddy]
Cantor and Dedekind brought completed infinities into mathematics [Maddy]
In the ZFC hierarchy it is impossible to form Frege's set of all three-element sets [Maddy]
Theorems about limits could only be proved once the real numbers were understood [Maddy]
Making set theory foundational to mathematics leads to very fruitful axioms [Maddy]
The line of rationals has gaps, but set theory provided an ordered continuum [Maddy]
Unified set theory gives a final court of appeal for mathematics [Maddy]
Set theory brings mathematics into one arena, where interrelations become clearer [Maddy]
Identifying geometric points with real numbers revealed the power of set theory [Maddy]
Completed infinities resulted from giving foundations to calculus [Maddy]
Axiom of Infinity: completed infinite collections can be treated mathematically [Maddy]
The Axiom of Foundation says every set exists at a level in the set hierarchy [Maddy]
'Forcing' can produce new models of ZFC from old models [Maddy]
A Large Cardinal Axiom would assert ever-increasing stages in the hierarchy [Maddy]
An 'inaccessible' cardinal cannot be reached by union sets or power sets [Maddy]
Scientists posit as few entities as possible, but set theorist posit as many as possible [Maddy]
The theoretical indispensability of atoms did not at first convince scientists that they were real [Maddy]
Science idealises the earth's surface, the oceans, continuities, and liquids [Maddy]
Maybe applications of continuum mathematics are all idealisations [Maddy]