1852 – 1939
Carl Louis Ferdinand von Lindemann (1852–1939) was a German mathematician whose 1882 proof that π is a transcendental number settled the ancient problem of squaring the circle. Beyond his landmark result in number theory, Lindemann engaged with foundational questions in the philosophy of geometry, situating him within late 19th-century debates about the epistemological status of mathematical axioms.
Proved the transcendence of π (1882), demonstrating that squaring the circle with compass and straightedge is impossible
Extended Hermite's method for proving e transcendental to establish a general transcendence theorem
Contributed to foundational debates on whether geometric axioms express truths or are conventional stipulations
Produced work in projective and non-Euclidean geometry during a period of intense foundational reassessment