Full Idea
Descartes founded analytic geometry on the assumption that there is a one-one order-preserving correspondence between the points on a line and the real numbers.
Gist of Idea
Descartes showed a one-one order-preserving match between points on a line and the real numbers
Source
report of René Descartes (works [1643]) by William D. Hart - The Evolution of Logic 1
Book Reference
Hart,W.D.: 'The Evolution of Logic' [CUP 2010], p.18