Karl Georg Christian von Staudt (24 January 1798 – 1 June 1867) was a German mathematician who used synthetic geometry to provide a foundation for arithmetic.

Indeed, in 1889 Mario Pieri translated von Staudt, before writing his I Principii della Geometrie di Posizione Composti in un Systema Logico-deduttivo (1898).

In 1900 Charlotte Scott of Bryn Mawr College paraphrased much of von Staudt's work in English for The Mathematical Gazette.

[2] When Wilhelm Blaschke published his textbook Projective Geometry in 1948, a portrait of the young Karl was placed opposite the Vorwort.

As Freudenthal notes[7]: 199 Another affirmation of von Staudt's work with the harmonic conjugates comes in the form of a theorem: The algebra of throws was described as "projective arithmetic" by John Stillwell (2005).

[9] In a section called "Projective arithmetic", he says If one interprets von Staudt's work as a construction of the real numbers, then it is incomplete.

As Hans Freudenthal observed: One of the Italian mathematicians was Giovanni Vailati who studied the circular order property of the real projective line.