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Single Idea 13899

[filed under theme 6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism ]

Full Idea

The Peano Axioms are logical consequences of a statement constituting the core of an explanation of the notion of cardinal number. The infinity of cardinal numbers emerges as a consequence of the way cardinal number is explained.

Gist of Idea

The Peano Axioms, and infinity of cardinal numbers, are logical consequences of how we explain cardinals

Source

Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xix)

Book Ref

Wright,Crispin: 'Frege's Conception of Numbers' [Scots Philosophical Monographs 1983], p.168


A Reaction

This, along with Idea 13896, nicely summarises the neo-logicist project. I tend to favour a strategy which starts from ordering, rather than identities (1-1), but an attraction is that this approach is closer to counting objects in its basics.

Related Ideas

Idea 13896 The aim is to follow Frege's strategy to derive the Peano Axioms, but without invoking classes [Wright,C]

Idea 17312 It is more explanatory if you show how a number is constructed from basic entities and relations [Koslicki]


The 38 ideas from Crispin Wright

The attempt to define numbers by contextual definition has been revived [Wright,C, by Fine,K]
An expression refers if it is a singular term in some true sentences [Wright,C, by Dummett]
Wright has revived Frege's discredited logicism [Wright,C, by Benardete,JA]
Wright thinks Hume's Principle is more fundamental to cardinals than the Peano Axioms are [Wright,C, by Heck]
We derive Hume's Law from Law V, then discard the latter in deriving arithmetic [Wright,C, by Fine,K]
Frege has a good system if his 'number principle' replaces his basic law V [Wright,C, by Friend]
Wright says Hume's Principle is analytic of cardinal numbers, like a definition [Wright,C, by Heck]
Contextually defined abstract terms genuinely refer to objects [Wright,C, by Dummett]
Logicism seemed to fail by Russell's paradox, Gödel's theorems, and non-logical axioms [Wright,C]
There are five Peano axioms, which can be expressed informally [Wright,C]
Number truths are said to be the consequence of PA - but it needs semantic consequence [Wright,C]
What facts underpin the truths of the Peano axioms? [Wright,C]
Number theory aims at the essence of natural numbers, giving their nature, and the epistemology [Wright,C]
We can only learn from philosophers of the past if we accept the risk of major misrepresentation [Wright,C]
Instances of a non-sortal concept can only be counted relative to a sortal concept [Wright,C]
Number platonism says that natural number is a sortal concept [Wright,C]
We can't use empiricism to dismiss numbers, if numbers are our main evidence against empiricism [Wright,C]
Sortal concepts cannot require that things don't survive their loss, because of phase sortals [Wright,C]
A concept is only a sortal if it gives genuine identity [Wright,C]
'Sortal' concepts show kinds, use indefinite articles, and require grasping identities [Wright,C]
Treating numbers adjectivally is treating them as quantifiers [Wright,C]
Singular terms in true sentences must refer to objects; there is no further question about their existence [Wright,C]
We can accept Frege's idea of object without assuming that predicates have a reference [Wright,C]
A milder claim is that understanding requires some evidence of that understanding [Wright,C]
The best way to understand a philosophical idea is to defend it [Wright,C]
The idea that 'exist' has multiple senses is not coherent [Wright,C]
If apparent reference can mislead, then so can apparent lack of reference [Wright,C]
Entities fall under a sortal concept if they can be used to explain identity statements concerning them [Wright,C]
If numbers are extensions, Frege must first solve the Caesar problem for extensions [Wright,C]
It is 1-1 correlation of concepts, and not progression, which distinguishes natural number [Wright,C]
One could grasp numbers, and name sizes with them, without grasping ordering [Wright,C]
Sameness of number is fundamental, not counting, despite children learning that first [Wright,C]
The Peano Axioms, and infinity of cardinal numbers, are logical consequences of how we explain cardinals [Wright,C]
The aim is to follow Frege's strategy to derive the Peano Axioms, but without invoking classes [Wright,C]
The standard objections are Russell's Paradox, non-logical axioms, and Gödel's theorems [Wright,C]
If we can establish directions from lines and parallelism, we were already committed to directions [Wright,C]
Holism cannot give a coherent account of scientific methodology [Wright,C, by Miller,A]
Logical necessity involves a decision about usage, and is non-realist and non-cognitive [Wright,C, by McFetridge]