This paper discusses the explanations for the causes and features of earthquakes in the works of philosopher and scientist Avicenna (980-1037) and in the theologian Fakhr al-Dīn al-Rāzī (1149-1209), who was deeply familiar with the work of Avicenna and who criticized him sharply on many occasions. The aim of this paper is to check the well-known hypothesis according to which Muslim theologians sometimes set out doctrines that were much more innovative from a scientific point of view than those of philosophers, strictly linked to Aristotle. This paper thus contributes to the history of Graeco-Arabic translations and the history of science. Avicenna's and Fakhr al-Dīn al-Rāzī's doctrines are compared with Aristotle and the Arabic tradition of the Meteorologica.Aristotle was a major source for theories about earthquakes, so we must first recall the extent to which his views were known to the Arabs. Aristotle dealt with earthquakes in Book II of his Meteorologica: in Chapter 7 he confutes the positions of Anaxagoras of Clazomenes, Democritus of Abdera and Anaximenes of Miletus and in Chapter 8 he expounds his own ideas. Aristotle on earthquakesAccording to Aristotle, earthquakes are caused by the pressure of air (pneuma) produced when the earth, which is in itself dry but may be moistened by rain, is heated by the sun and by its internal fire. Earthquakes mostly occur when this pneuma makes rising vapour (anathymiasis) flow back into the earth: this happens mainly in calm weather, though earthquakes may occur when winds (à nemoi) blow because they contribute to making the pneumata turn inwards. Severe earthquakes occur when the sea is full of currents and when the earth is porous: in these cases seawater fills the pores of the earth, forcing out pneumata. Rains and droughts produce similar effects.Phenomena related to earthquakes such as dimming of the sun are noted. This occurrence is not explained, but Aristotle does explain why calm and cold usually precede an earthquake and why a long streak of fine cloud may herald one; he later explains why earthquakes can occur at an eclipse of the moon. Aristotle also states that the effects of severe shocks frequently persist for 40 days and even for periods of one year or two. Subterranean noises during earthquakes are discussed, and the reasons why water may come out of the earth -in this case, the pneuma exerts its force from beneath. Tidal waves are caused by pneumata acting in the opposite direction.Aristotle remarks that earthquakes are confined to one locality while winds (à nemoi) are not. He considers that horizontal shocks are determined by large quantities of pneuma; on rare occasions, shocks may run up from below, when large quantities of stones come to the surface. Finally, he explains why earthquakes are rarer in islands.Aristotle's Meteorologica in Arabic is known through the translation by Yahyā ibn al-Bitrīq, 1 who died in 830. A summary by Hunayn ibn Ishāq (808-873), the most famous of Arabic translators, is also available. 2 Yahyā ibn al-Bitrīq's versionYa...

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The aim of this paper is to identify the position the ru'yat Allāh holds within the curriculum of sciences described by the Iḫwān al-Ṣafa'. Their concept of knowledge is first clarified. The Ihwan use the terminology of rational knowledge to describe items of faith too. But faith is only an introduction to a greater knowledge. Now: is the supreme knowledge to be considered as speculative and theoretical, or are the ḫawciṣṣ, the only ones entitled to the vision of God, eventually obliged to rely on a kind of divine “revelation” or “inspiration”? If the “vision of God” appears beyond any possible connotation of knowledge in “rational” terms, it is unclear, however, whether the Ihwan use the concepts of “revelation” and “inspiration” as a way of explaining in a theological terminology the utmost degree of human knowledge (perhaps according to the same analogical function waḥy and ilhām appear to have in Ibn Sīnā). Moreover, the qualities and moral dispositions attributed to the “Friends of God” remind us of Sufi doctrines. Consequently, the question of the relation between Sufism and imāmite theories could be re-opened: the Iḫwānian definition of the “science of the transcendent” shows that the gnoseological itinerary is not concluded even with the “vision of God.”