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Single Idea 13190

[filed under theme 6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite ]

Full Idea

Notwithstanding my infinitesimal calculus, I do not admit any real infinite numbers, even though I confess that the multitude of things surpasses any finite number, or rather any number. ..I consider infinitesimal quantities to be useful fictions.

Clarification

[Leibniz was one of the inventors of calculus]

Gist of Idea

I don't admit infinite numbers, and consider infinitesimals to be useful fictions

Source

Gottfried Leibniz (Letters to Samuel Masson [1716], 1716)

Book Ref

Leibniz,Gottfried: 'Philosophical Essays', ed/tr. Arlew,R /Garber,D [Hackett 1989], p.229


A Reaction

With the phrase 'useful fictions' we seem to have jumped straight into Harty Field. I'm with Leibniz on this one. The history of mathematics is a series of ingenious inventions, whenever they seem to make further exciting proofs possible.


The 11 ideas with the same theme [treating an infinite collection as a complete thing]:

If there were real infinities, you could add two together, which is ridiculous [Locke]
I strongly believe in the actual infinite, which indicates the perfections of its author [Leibniz]
I don't admit infinite numbers, and consider infinitesimals to be useful fictions [Leibniz]
Actual infinities are not allowed in mathematics - only limits which may increase without bound [Gauss]
Cantor proposes that there won't be a potential infinity if there is no actual infinity [Cantor, by Hart,WD]
Poincaré rejected the actual infinite, claiming definitions gave apparent infinity to finite objects [Poincaré, by Lavine]
The idea of an infinite totality is an illusion [Hilbert]
Cantor and Dedekind brought completed infinities into mathematics [Maddy]
Completed infinities resulted from giving foundations to calculus [Maddy]
Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read]
The classical mathematician believes the real numbers form an actual set [George/Velleman]