  8.3 Avicenna, Kitab al-Shifa’, Meteorology  In the third chapter of Ma’amar Yiqqawu ha-Mayim, Ibn Tibbon presents a partial translation of a section from Avicenna’s Shifa’ on mountain formation. The theory of Avicenna—that erosion is prevented by the mixture of mud with fatty oils—contributed to Ibn Tibbon’s discussion there of eternity of the world and the possibility of spontaneous generation.