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Single Idea 13474

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

Full Idea

There is a familiar comparison between Euclid (unique parallel) and 'spherical' geometry (no parallel) and 'saddle' geometry (several parallels).

Gist of Idea

Euclid has a unique parallel, spherical geometry has none, and saddle geometry has several

Source

William D. Hart (The Evolution of Logic [2010], 2)

Book Ref

Hart,W.D.: 'The Evolution of Logic' [CUP 2010], p.44