englischBERNARD BOLZANO (1781-1848) is one of the great figures in the history of ideas. As a philosopher and in particular as a logician he did pioneering work which led the way for basic research in logic and methodology of the 20th century. Bolzano was professor of the science of (Roman Catholic) religion at the Philosophical Faculty of the University of Prague. He was also a first-rate mathematician, and several of his results have even found their way into standard textbooks of mathematics. In addition, he was very much interested in natural sciences, especially physics. It is this wide range of Bolzano's interests and the versatility of his work which, in combination with the circumstances of his life and the publication ban imposed on him, have impeded a final and balanced acknowledgment of his scientific achievements. It is only thanks to the Bernard-Bolzano-Gesamtausgabe, the critical edition of his collected works including his literary remains and correspondence, that the full significance of Bolzano's scientific work is gradually becoming apparent. So far, 75 volumes of the edition have been published and about 50 more are still to appear. Only when the edition is complete will a final assessment be possible. Nevertheless, we are long overdue an interim report. The present book is intended to fill this gap. It provides the reader with an assessment of Bolzano's work in its full breadth for the first time in a century, from the point of view of the latest developments of Bolzano research, and in English.