From 1805 to 1820, Bernard Bolzano was professor of religious doctrine (Religionslehre) at the University of Prague. The lectures he had to deliver were part of the so-called Philosophical Studies that every student of the university had to complete before he entered the higher studies, i.e. the studies of medicine, law or theology. As professor of religious doctrine, Bolzano also had the duty to deliver the homilies on Sundays and holidays during the academic year to all the students of the Philosophical Studies. This explains the enormous influence Bolzano exerted through these homilies on the intellectual and political life of Bohemia in his time, whose offshoots reached even the Charta 77 movement in former Czechoslovakia. The chairs of religious doctrine were established by the Austrian emperor Franz at all universities of the Austrian empire in order to shape the students into good Christians and law-abiding citizens as it was ordered in a decree. The homilies Bolzano had to deliver at the University of Prague (as did all professors of religious doctrine at Austrian universities) were called Erbauungsreden (edifying addresses) or exhortations. There is evidence for 582 Erbauungsreden Bolzano delivered as a professor at the University of Prague of which 414 are extant; of these, 153 have not yet been published at all. The 414 Erbauungsreden that are extant have survived in different form: some of them (70) as autographs, i.e. in Bolzano's own handwriting, others in handwritten copies of Bolzano's manuscripts, others in notes taken by Bolzano's students. Several collections of Bolzano's Erbauungsreden have already appeared in print, some of them during Bolzano's lifetime, while others were published posthumously by his students or other editors. - The new critical edition of Bolzano's Erbauungsreden presents all of them in chronological order. Those which are extant will be edited on the basis of the best version which has remained. Those Erbauungsreden which are not extant will be documented and described according to an index Bolzano himself has prepared.In Bernard Bolzano's first four academic years as a professor at the University of Prague he held 169 edification speeches, of which however only 13 have been preserved. An index which Bolzano compiled himself does however provide information on the content of all the other edification speeches held during this time. This volume contains a complete documentation of all the edification speeches which Bolzano held up to the end of the academic year 1807/08. In den ersten vier Studienjahren, in denen Bernard Bolzano als Professor an der Universitat Prag tatig war, hat er 169 Erbauungsreden gehalten, von denen jedoch nur 13 erhalten sind. Ein von Bolzano selbst verfasstes Verzeichnis gibt aber auch uber den Inhalt aller anderen Erbauungsreden aus dieser Zeit Auskunft. So bietet dieser Band eine vollstandige Dokumentation samtlicher Erbauungsreden, die Bolzano bis zum Ende des Studienjahres 1807/ 08 gehalten hat. 'This first volume of [Erbauungsreden] follows the same high scholarly standards as previous volumes of this monumental edition of Bolzano's works.' Albert C. Lewis, Zentralblatt Mathematik