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Single Idea 6297

[filed under theme 6. Mathematics / A. Nature of Mathematics / 2. Geometry ]

Full Idea

Euclid's geometry is a synthetic geometry; Descartes supplied an analytic version of Euclid's geometry, and we now have analytic versions of the early non-Euclidean geometries.

Clarification

'Synthetic' relates to experience; 'analytic' is pure definitions

Gist of Idea

Euclid's geometry is synthetic, but Descartes produced an analytic version of it

Source

report of Euclid (Elements of Geometry [c.290 BCE]) by Michael D. Resnik - Maths as a Science of Patterns One.4

Book Ref

Resnik,Michael D.: 'Mathematics as a Science of Patterns' [OUP 1999], p.55


A Reaction

I take it that the original Euclidean axioms were observations about the nature of space, but Descartes turned them into a set of pure interlocking definitions which could still function if space ceased to exist.


The 12 ideas from 'Elements of Geometry'

Proof reveals the interdependence of truths, as well as showing their certainty [Euclid, by Frege]
If you pick an arbitrary triangle, things proved of it are true of all triangles [Euclid, by Lemmon]
Euclid's geometry is synthetic, but Descartes produced an analytic version of it [Euclid, by Resnik]
An assumption that there is a largest prime leads to a contradiction [Euclid, by Brown,JR]
Postulate 2 says a line can be extended continuously [Euclid, by Shapiro]
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]
A unit is that according to which each existing thing is said to be one [Euclid]
Euclid's common notions or axioms are what we must have if we are to learn anything at all [Euclid, by Roochnik]