''Paradoxes of the Infinite'' (German title: ''Paradoxien des Unendlichen'') is a mathematical work by

Bernard Bolzano
Bernard Bolzano (, ; ; ; born Bernardus Placidus Johann Nepomuk Bolzano; 5 October 1781 – 18 December 1848) was a Bohemian
A Bohemian () is a resident of Bohemia
Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost an ...

on the theory of sets. It was published by a friend and student, František Přihonský, in 1851, three years after Bolzano's death.
The work contained many interesting results in set theory. Bolzano expanded on the theme of Galileo's paradox, giving more examples of correspondences between the elements of an infinite set and proper subsets of infinite sets. In the work he also explained the term ''Menge'', rendered in English as "set", which he had coined and used in several works since the 1830s.
References

* ''Paradoxes of the Infinite''; trans. by D.A.Steele; London: Routledge, 1950 * (German original) * History of mathematics Infinity Logic literature Set theory 1851 essays Works published posthumously {{mathlogic-stub