Rudolf Carnap

Rudolf Carnap (/ˈkɑːrnæp/;German: [ˈkaɐ̯naːp]; May 18, 1891 – September 14, 1970) was a German-born philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism. He is considered "one of the giants among twentieth-century philosophers."

Carnap's father had risen from the status of a poor ribbon-weaver to become the owner of a ribbon-making factory. His mother came from academic stock; her father was an educational reformer and her oldest brother was the archaeologist Wilhelm Dörpfeld. As a ten-year-old, Carnap accompanied his uncle on an expedition to Greece. Carnap was raised in a religious family, but later became an atheist.

He began his formal education at the Barmen Gymnasium. From 1910 to 1914, he attended the University of Jena, intending to write a thesis in physics. But he also studied carefully Kant's Critique of Pure Reason during a course taught by Bruno Bauch, and was one of very few students to attend Gottlob Frege's courses in mathematical logic. While Carnap held moral and political opposition to World War I, he felt obligated to serve in the German army. After three years of service, he was given permission to study physics at the University of Berlin, 1917–18, where Albert Einstein was a newly appointed professor. Carnap then attended the University of Jena, where he wrote a thesis defining an axiomatic theory of space and time. The physics department said it was too philosophical, and Bruno Bauch of the philosophy department said it was pure physics. Carnap then wrote another thesis in 1921, with Bauch's supervision, on the theory of space in a more orthodox Kantian style, and published as Der Raum ("Space") in a supplemental issue of Kant-Studien (1922). In it he makes the clear distinction between formal, physical and perceptual (e.g., visual) spaces.