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Single Idea 12937

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry ]

Full Idea

Far from approving the acceptance of doubtful principles, I want to see an attempt to demonstrate even Euclid's axioms, as some of the ancients tried to do.

Gist of Idea

We shouldn't just accept Euclid's axioms, but try to demonstrate them

Source

Gottfried Leibniz (New Essays on Human Understanding [1704], 1.02)

Book Ref

Leibniz,Gottfried: 'New Essays on Human Understanding', ed/tr. Remnant/Bennett [CUP 1996], p.101


A Reaction

This is the old idea of axioms, as a bunch of basic self-evident truths, rather than the modern idea of an economical set of propositions from which to make deductions. Demonstration has to stop somewhere.

Related Ideas

Idea 574 Not everything can be proven, because that would lead to an infinite regress [Aristotle]

Idea 1672 Maybe everything could be demonstrated, if demonstration can be reciprocal or circular [Aristotle]


The 21 ideas with the same theme [formal starting points for deriving geometry]:

Euclid relied on obvious properties in diagrams, as well as on his axioms [Potter on Euclid]
Euclid's parallel postulate defines unique non-intersecting parallel lines [Euclid, by Friend]
Euclid needs a principle of continuity, saying some lines must intersect [Shapiro on Euclid]
Euclid says we can 'join' two points, but Hilbert says the straight line 'exists' [Euclid, by Bernays]
Modern geometries only accept various parts of the Euclid propositions [Russell on Euclid]
Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]
We shouldn't just accept Euclid's axioms, but try to demonstrate them [Leibniz]
Euclid's could be the only viable geometry, if rejection of the parallel line postulate doesn't lead to a contradiction [Benardete,JA on Kant]
The whole of Euclidean geometry derives from a basic equation and transformations [Hilbert]
Euclid axioms concerns possibilities of construction, but Hilbert's assert the existence of objects [Hilbert, by Chihara]
Hilbert's formalisation revealed implicit congruence axioms in Euclid [Hilbert, by Horsten/Pettigrew]
Hilbert's geometry is interesting because it captures Euclid without using real numbers [Hilbert, by Field,H]
Geometry is united by the intuitive axioms of projective geometry [Russell, by Musgrave]
Tarski improved Hilbert's geometry axioms, and without set-theory [Tarski, by Feferman/Feferman]
There are four different possible conventional accounts of geometry [Quine]
Modern axioms of geometry do not need the real numbers [Bostock]
'Metric' axioms uses functions, points and numbers; 'synthetic' axioms give facts about space [Field,H]
Euclid has a unique parallel, spherical geometry has none, and saddle geometry has several [Hart,WD]
Analytic geometry gave space a mathematical structure, which could then have axioms [Chihara]
The culmination of Euclidean geometry was axioms that made all models isomorphic [McGee]
In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki]