Library SARC Research Person
Georg Cantor
German mathematician who founded set theory and the study of transfinite numbers and the infinite.
Georg Cantor (1845–1918) founded set theory, proving that infinite sets come in different sizes and developing the transfinite cardinal and ordinal numbers used to measure them. Trained at the University of Berlin under Karl Weierstrass and Ernst Kummer, he found in Richard Dedekind a close early interlocutor — the two spent much of Cantor’s 1874 honeymoon in mathematical discussion — while Leopold Kronecker, opposed on principle to actually-infinite quantities, dismissed him as a “corrupter of youth” and blocked his advancement to a Berlin professorship. Cantor’s work found a later, more sympathetic reception in David Hilbert, who defended it as mathematical “paradise,” and in John von Neumann, whose 1923 definition of the ordinal numbers superseded Cantor’s own and whose doctoral thesis produced an axiomatization of Cantor’s set theory.