L’acqua che si trasforma in pietra. Gundissalinus e Avicenna sulla generazione dei metalli

What are the sources of a curious example of generation mentioned by Gundissalinus, by which water becomes a stone? This contribution explores the theoretical aims of the example presented in De processione mundi, assessing the Avicennian doctrinal framework in which it is placed by Gundissalinus. The origin of the example itself, though, appears to be far more complicated. After examining possible Latin sources and the alchemical implications suggested by the example, the study focuses on a different hypothesis: that Gundissalinus had access to the Arabic version of Avicenna’s De generatione and corruptione.