El artículo tiene por objetivo analizar ciertos pasajes fundamentales de la Wissenschaftslehre y de las Paradoxien des Unendlichen de Bernard Bolzano en cuanto al análisis conjuntista se refiere. En dichos pasajes, Bolzano desarrolla conceptos fundamentales tales como multitud, colección e infinito que anticipan el carácter conjuntista y del análisis matemático moderno. Asimismo, se presentará un breve estudio de las Contribuciones a una más fundada exposición de la matemática y el apéndice, Sobre la teoría kantiana de la construcción de conceptos a (...) través de intuiciones, textos donde Bolzano muestra su rechazo por Kant.The article addresses the treatment of certain fundamental passages from Bolzano’s Wissenschaftslehre and Paradoxien des Unendlichen. In these passages, Bolzano describes some of his key concepts such “Multitude”, “Collections” and “Infinite” in the context of mathematical analysis and Set theory. Therefore, I discuss at length the unknown Contributions to a Better-Grounded Presentation of Mathematics and the appendix On the Kantian Theory of the Construction of Concepts through Intuitions, texts where Bolzano shows his rejection of Kant. (shrink)

This volume will be of particular interest to researchers working in the history, and in the philosophy, of logic and mathematics, and more generally, to ...

In his Foundations of a General Theory of Manifolds, Georg Cantor praised Bernard Bolzano as a clear defender of actual infinity who had the courage to work with infinite numbers. At the same time, he sharply criticized the way Bolzano dealt with them. Cantor’s concept was based on the existence of a one-to-one correspondence, while Bolzano insisted on Euclid’s Axiom of the whole being greater than a part. Cantor’s set theory has eventually prevailed, and became a formal basis of contemporary (...) mathematics, while Bolzano’s approach is generally considered a step in the wrong direction. In the present paper, we demonstrate that a fragment of Bolzano’s theory of infinite quantities retaining the part-whole principle can be extended to a consistent mathematical structure. It can be interpreted in several possible ways. We obtain either a linearly ordered ring of finite and infinitely great quantities, or a partially ordered ring containing infinitely small, finite and infinitely great quantities. These structures can be used as a basis of the infinitesimal calculus similarly as in non-standard analysis, whether in its full version employing ultrafilters due to Abraham Robinson, or in the recent “cheap version” avoiding ultrafilters due to Terence Tao. (shrink)

Alongside his groundbreaking work in logic, Bernard Bolzano (1781?1848) made important contributions to ontology, notably with his theory of collections. Recent work has done much to elucidate Bolzano's conceptions, but his notion of a sum has proved stubbornly resistant to complete understanding. This paper offers a new interpretation of Bolzano's concept of a sum. I argue that, although Bolzano's presentation is defective, his conception is unexceptionable, and has important applications, notably in his work on the foundations of arithmetic.