Ǧābir ibn Ḥayyān über die Autorenschaft der Präambel zu Euklids Elementen: Zur Zweckursache im Kitāb al-Baḥṯ

Some Arabic versions of Euclid’s Elements begin with an epistemological passage on how to obtain knowledge. This passage does not go back to Euclid but to Proclus’ commentary on the first book of the Elementswhere Proclus does not consider the epistemological process in general yet specifically deals with geometrical problems and theorems. In the Book of Investigation (Kitāb al-Baḥṯ) attributed to the legendary alchemist Ǧābir ibn Ḥayyān, part of this pseudo-Euclidian passage is cited and its authorship questioned. The article presents the Arabic text and a German translation of Ǧābir’s discussion as well as the astonishing context in which he places the pseudo-Euclidian citation, namely within an exposition of the final cause. Ǧābir also deals with the question of whether or not the final cause is part of the definition. In doing so, he shows a remarkable familiarity with Late Antique introductory literature which was incredibly widespread in the Arabic tradition.