 Like most of his other philosophical works, Israeli’s Arabic original (Kitab al-Ustuqussat) is lost, and we are left with a Latin translation and two Hebrew versions. Gerard of Cremona’s Latin translation of this book was published in the work Omnia opera Ysaac, Lyons: 1515. One Hebrew version (Leiden, Warner MS No. 13) was rendered by Abraham ibn Hasday for David Qimhi. The other translation (Munich MS No. 43) is more eloquent, and likely an improvement on the earlier translation, leading Salomon Fried to conjecture that the famous Medieval translator Moses ibn Tibbon (flourished mid-13th century, Provence) prepared it (Fried, 1884, pp. 75–83).