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Single Idea 8742

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers ]

Full Idea

Mill says arithmetic has two axioms, that 'things which are equal to the same thing are equal to each other', and 'equals added to equals make equal sums', plus a definition for each numeral as 'formed by the addition of a unit to the previous number'.

Gist of Idea

The only axioms needed are for equality, addition, and successive numbers

Source

report of John Stuart Mill (System of Logic [1843], p.610?) by Stewart Shapiro - Thinking About Mathematics 4.3

Book Ref

Shapiro,Stewart: 'Thinking About Mathematics' [OUP 2000], p.95


A Reaction

The difficulty here seems to be the definition of 1, and (even worse for an empiricist), of 0. Then he may have a little trouble when he reaches infinity.


The 20 ideas with the same theme [general ideas about giving arithmetic a formal basis]:

We know mathematical axioms, such as subtracting equals from equals leaves equals, by a natural light [Leibniz]
Kant suggested that arithmetic has no axioms [Kant, by Shapiro]
Axioms ought to be synthetic a priori propositions [Kant]
The only axioms needed are for equality, addition, and successive numbers [Mill, by Shapiro]
Dedekind gives a base number which isn't a successor, then adds successors and induction [Dedekind, by Hart,WD]
Arithmetical statements can't be axioms, because they are provable [Frege, by Burge]
If principles are provable, they are theorems; if not, they are axioms [Frege]
Numbers have been defined in terms of 'successors' to the concept of 'zero' [Peano, by Blackburn]
Number theory just needs calculation laws and rules for integers [Hilbert]
The definition of order needs a transitive relation, to leap over infinite intermediate terms [Russell]
Axiom of Archimedes: a finite multiple of a lesser magnitude can always exceed a greater [Russell]
It is conceivable that the axioms of arithmetic or propositional logic might be changed [Putnam]
For Zermelo 3 belongs to 17, but for Von Neumann it does not [Benacerraf]
The successor of x is either x and all its members, or just the unit set of x [Benacerraf]
Mathematics is generalisations about singleton functions [Lewis]
The number of Fs is the 'successor' of the Gs if there is a single F that isn't G [Smith,P]
All numbers are related to zero by the ancestral of the successor relation [Smith,P]
Mereological arithmetic needs infinite objects, and function definitions [Reck/Price]
The truth of the axioms doesn't matter for pure mathematics, but it does for applied [Mares]
It is more explanatory if you show how a number is constructed from basic entities and relations [Koslicki]