 In the Encylopédie Méthodique (1784: vol. 2, 132), d’Alembert defined geometry as the science of the properties of extension, i.e., of bodies (and surfaces and lines) considered as merely extended and figured. Its principles are founded, in his view, on truths so evident that it is not possible to contest them. A line (in the sense of a curve) is one-dimensional, and the shortest line joining two points is the straight line. Parallel lines are lines that, however far they are extended, will never meet because they are everywhere equidistant. D'Alembert was not keen on axiomatic presentation of the material, and so it was also with many other eighteenth-century authors.