Bernard Bolzano (1781 - 1848)

Bernard Bolzano

Bernard Bolzano, full name Bernard Placidus Johann Nepomuk Bolzano, was an Italian-born Czech scientist, mathematician, logician, philosopher and theologian.

Bolzano graduated from the University of Prague and was immediately appointed professor of philosophy and religion at the university. Within a few years, however, Bolzano had already shown himself to be a free thinker with his teachings on the social costs of militarism and the needlessness of war. He called for a complete reform of the educational, social, and economic systems that would direct the nation's interests toward peace rather than armed conflict between states. In 1819, Bolzano was expelled from the university for his beliefs and thereafter turned his full attention to works on social, religious, philosophical, and mathematical issues.

Bolzano held advanced views on logic, mathematical quantities, limits, and continuity. He is the author of the first rigorous theory of real numbers and one of the founders of set theory. In his studies of the physical aspects of force, space, and time, he proposed theories opposed to those advanced by the German philosopher Immanuel Kant. His contributions to logic, in particular, established his reputation as the greatest logician of his time. Much of his work remained unpublished during his lifetime and was not widely disseminated until the late nineteenth and early twentieth centuries, when a number of his conclusions were reached independently.

Bolzano was multi-talented in various fields of science to which he made significant contributions. His published works include The Binomial Theorem (1816), A Purely Analytic Proof (1817), The Functional Model and the Scientific Model (1834), An Attempt at a New Statement of Logic (1837), and The Paradoxes of Infinity (1851).

Among other things, Bolzano was also a great philanthropist. Together with his friends and students, he supported the activities of almshouses, homes for the blind, loan banks for the working class, libraries, and elementary schools in rural areas.