 As for al-Farabi’s most famous work, the Book of the Opinions of the People of the Virtuous City (Kitab ara’ ahl al-madina al-fadila), apart from some short quotations found in Moses Ibn Ezra’s Treatise of the Garden (Fenton 1976, 297) and in Isaac Ibn Latif’s above mentioned work (Chiesa 1986, 80), the most relevant employment of this text as a source for metaphysics and theology is found in Falaquera’s Book of Degrees and in particular in book ten of his encyclopedia The Opinions of the Philosophers, where his general treatment of the nature of God mixed up al-Farabi’s and Averroes’ opinions about it (Chiesa 1986, 81–84). Al-Farabi’s Virtuous City appears to have been ignored by most of Medieval Jewish philosophers: as a matter of fact, Moses Ibn Tibbon did not translate it into Hebrew, but preferred to translate al-Farabi’s The Political Regimen (al-Siyasa al-madaniyya) instead (Steinschneider 1893, 290–292) – another Farabian text known and quoted by Falaquera (Plessner 1956, 189–193). According to Pines, although al-Farabi’s former work is not explicitely quoted in the Guide of the Perplexed, it was surely among the main sources of Maimonides’ doctrine about the different roles played by the philosopher and by the prophet (see Moses Maimonides 1962, 1:lxxxvii-xcii). Al-Farabi’s idea about the relationship between philosophy and religion, according to which the former is in a substantially higher position with respect to the latter, as found in his Book on Letters (Kitab al-huruf) and Book on Religion (Kitab al-milla), strongly influenced Maimonides’ ideas about this (see Berman 1974); moreover, the Book on Letters was later employed as a source for Falaquera’s treatment of linguistics in his Beginning of Science. According to Davidson, Maimonides explicitly quoted and employed al-Farabi’s Political Regime under the title The Changing Beings (al-Mawjudat al-mutaghayyira) for discussing the question of the world’s eternity in part two, chapter 74, of the Guide (Davidson 2005, 113). It should be noted that European Jewish philosophers active in the 13th and 14th centuries show even more interest in another work by al-Farabi: his treatise On the Intellect (Risala fi l-‘aql). This interest was apparently raised by Maimonides, who quoted and commented on some passages of this book about the theologians’ idea of the human intellect and the role of the active intellect in his Guide (see what has been written by Pines in Moses Maimonides 1962, 1:lxxxii-lxxxiii). As recently shown by Gad Freudenthal, at least three Arabic-into-Hebrew versions of the work (one by Qalonymos ben Qalonymos, and two anonymous) were written, read and in one case at least commented on in Western Europe between about 1150 and 1320 (Freudenthal 2003). Moreover, Farabian doctrines (if not direct references to al-Farabi’s works) about some key concepts of metaphysics and theology (the First Cause, the prophecy, etc.) were still circulating in Spain around 1350 (see Vajda 1962, 216–217, where these doctrines are found in Joseph Ibn Waqqar’s work). 