[This is a draft of an article in The Dictionary of Eighteenth Century German Philosophers, 3 vols., edited by Manfred Kuehn and Heiner Klemme (London/New York: Continuum, 2010).]
Johann Friedrich Gensichen was born in 1759, and died in Königsberg on 7 September 1807. He was a respected professor of mathematics at the university in Königsberg and a close associate of Kant’s in his later years. Gensichen matriculated at the university on 29 July 1778, a talented student whose poverty found him free lodging for several years in the home of his mathematics professor Johann Schultz [bio], who was a close colleague of Kant’s and an early and careful interpreter of Kant’s writings.
Gensichen habilitated at Königsberg on 15 September 1790 and began offering mathematics lectures, primarily on pure and applied arithmetic and algebra. Since the summer semester of 1795 Gensichen was associate professor of mathematics and the assistant inspector of the Alumnat [glossary]. As associate professor he was required to teach one course publicly each semester — usually applied arithmetic using Schultz’s textbook — and in all his years teaching he lectured only on mathematics, and only rarely offered more than two courses per term. During the 1790s he also served as the assistant university librarian.
It was no doubt through Schultz that Gensichen made Kant’s acquaintance, with whom he soon became a frequent dinner guest and trusted friend. In 1791, and at Kant’s request, Gensichen published a selection from Kant’s early cosmological work, the Theory of the Heavens (1755)[writings], a book scarcely known at the time because its publisher had gone bankrupt before the book was distributed. The purpose of this new publication was, among other things, to show that Kant had proposed his nebular hypothesis of the universe long before Lambert’s more recent and independent speculations (see Kant’s letter to Gensichen, 19 April 1791). Kant named Gensichen as the executor of his will (later replaced by Wasianski), and also left him his small library,[1] which was then auctioned after Gensichen’s death.
[1] On naming Gensichen as executor and leaving him Kant’s library, see AA 12: 384: “Damit nun dieser mein letzter Wille gehörig vollzogen und meinen Erben sowie den Legatarien ihre Erbtheile und Vermächtnisse richtig und sicher ausgeantwortet werden, so ernenne ich zum Executor Testamenti den Herrn Professor Gensichen und im Fall der Verweigerung oder Absterben desselben den Herrn Professor Poerschke [...] Von der Vererbung meines übrigen Hausgeräthes nehme ich doch meinen ganzen Büchervorrath aus als den ich dem Herrn Professor Gensichen vermache” (26 Feb 1798). See also Adickes’s discussion at AA 14: xxiii-xxiv.
On naming Wasianski as executor, see AA 12: 386: “Constituire ich den Herrn Diaconus Wasiansky zum Curator funeris und executor testamenti [...]” (14 Dec 1801).
De figuris inscriptis maximis nec non de figuarum divisione (Königsberg: Hartung, 1790).
Bemerkungen über die Theorien der Parallelen des Herrn Hofprediger Schultz und der Herren Gensichen und Bendavid (Libau: Johann Daniel Friedrich, 1796).
(editor), William Herschel, Über den Bau des Himmels. Drey Abhandlungen aus dem Englischen übersetzt von Michael Sommer. Nebst einem authentischen Auszug aus Kants allgemeiner Naturgeschichte und Theorie des Himmels (Königsberg, 1791).
Abegg, Walter and Jolanda, eds., Johann Friedrich Abegg, Reisetagebuch von 1798 (Insel Verlag, 1976), pp. 176-77, 193.
Hamberger/Meusel (1808), vol. 1, p. 454.
Metzger, Johann Daniel, Über die Universität zu Königsberg. Ein Nachtrag zu Arnoldt und Goldbeck (Königsberg, 1804), p. 68-69.
Stark, Werner, Nachforschungen zu Briefen und Handschriften Immanuel Kants (Berlin: Akademie Verlag, 1993), pp. 29-32.
Vorländer, Karl, Immanuel Kant: Das Mann und das Werk (Leipzig, 1924), vol. 1, p. 104, vol. 2, pp. 78. 86. 258.