LEIBNITZ, GOTTFRIED WILHELM. [THE LEIBNIZ CALCULATOR]

Theodicaea, Oder Versuch und Abhandlung, Wie der Güte und Gerechtigkeit Gottes, In Ansehung Der Menschlichen Freyheit, und des Ursprungs des Bösen, zu vertheidigen; Aus dem Frantzösischen übersetzt, Bei diesen dritten Auflage an vielen Orten verbessert. Nebst einigen Anmerckungen und nöthigen Registern Dem annoch beygefügt Des seeligen Herrn Autoris Lebens=Beschreibung.

Hannover, Zu finden bey Nicolai Försters und Sohns sel. Erben, 1735. 8vo. Cont.full vellum w. author and title in old hand on back. Bdg. a bit soiled. Internally a bit of brownspotting., title-page w. professionally repaired tear. Inner front-hinge starting to crack, but bdg. and bookblock tight. Overall a good and fairly well preserved copy. With engr. portrait, woodcut vignettes and one folded engr. plate depicting an early calculating machine. (28), 64, 1030 pp.

Rare third German edition. Last Richter-edition. First published in French in 1710. It is the only larger philosophical work, Leibnitz himself published and it is a work of immense importance to philosophy, theology and mathematics. In this work Leibniz represents his excellent calculating machine, which has served as the basis for what we now call a computer, as he presents the binary arithmetic, "Rechnen mit Null und Eins" ("calculating with zero and one") in the Beylage (p. 926), which forms the basis for the much later developed computer science (see PMM 177).
This work contains "Anmerkungen" by Richter and "Lebens=Beschreibung" by Fontenelle, followed by "Beylage". In these "Beylage" we find the method of converting numbers into the binary system, which here is said to be "etwas recht neues, welches der Herr Leibnitz zu Hanover erfunden" ("something brand new, which Mr. Leibnitz von Hanover has discovered") as well as "Eine Schrift. In welcher klar gezeiget wird/ dass nicht Herr Neuton,sondern der Herr von Leibnitz Erfinder des CALCULI DIFFERENTIALIS sey." (A Treatise. In which it is clearly shown/ that Mr. Leibniz and not Mr. Newton is the inventor of the CALCULI DIFFERENTIALIS").
All early editions of the Theodicee are rare. See D.S.B.: VIII, pp. 161-166.

Order-nr.: 28333