``I have learned non-Euclidean geometry just from this book'' -- some facets of the correspondence between Friedrich Engel and David Hilbert (Q2041235)

As its title indicates, this brief paper concerns some aspects of the correspondence between Friedrich Engel and David Hilbert, which began in the Spring of 1886 (the letters are now held in the respective Nachlässe in Giessen and Göttingen: 27 surviving letters from Hilbert to Engel, and 30 in the opposite direction). Two themes are explored in particular: the influence of Moritz Pasch on Hilbert's views on the foundations of geometry (hence the quotation in the title), and the wider context of Hermann Minkowski's appointment to an associate professorship in Göttingen. The paper begins with a dedication to Heinrich Wefelscheid (1941--2020).