units, and because the collection is infinite (for multiplication can continue indefinitely), the Indians ingeniously enclosed this infinite multiplicity within certain rules and limits so that infinity could be scientifically defined; these strict rules enabled them to pin down this subtle concept.” John of Seville is also credited with working in collaboration with Dominicus Gundissalinus and Jewish philosopher Abraham Ibn Daud to translate the De anima of Avicenna, a philosophical commentary on Aristotle's writings. Avicenna had many other of his works translated such as a philosophical encyclopedia titled Kitab al-Shifa’ (The Book of Healing) and a short script on metaphysics titled Liber de Causis (Book of Causes). John even retranslated an original Avicenna translation of Aristotle’s On the Heavens. It is speculated that the written work of Zael, titled Liber temporum, may have been translated by John of Seville. However, the name of the translator was never mentioned in the manuscript so it remains uncertain. A work by Jewish philosopher Avencebrol is believed to be translated by both John of Seville and Dominicus Gundissalinus titled Fons Vitae (Source of Life). Another one of John of Seville's philosophical translation includes the work by philosopher Al-Ghazali titled Maqasid al-falasifa (The Aims of the Philosophers), a book regarding basic philosophical concepts such as judgement, concept and logic. Original In addition to his many translations John of Seville is credited with a work of his own titled, Epitome artis astrologiae, written in 1142 which is a summary of astrology as a whole. Copying Errors The work of John of Seville was later preserved by medieval scholars through the copying of his translations. These copies occasionally deviate from John's original text, producing errors that further perpetuate the issue of John's identity. When the name of a translator was improperly copied into a manuscript, further copies of this manuscript would carry this error, initiating a mutation of names and dates over the span of multiple copies. Carelessness further complicated the matter. Abbreviations such as "Ioh Hisp" (Iohannes Hispalensis was yet another possible identity for John) were used, such as in a manuscript from 1503. Fortunately, a number of factors have aided in determining whether certain translations belong to John of Seville. He would often sign his translations "Cum laude Dei et eius adiutorio," making otherwise error-ridden manuscripts easily attributable to John. See also New Christian: converso & marrano Toledo School of Translators Latin translations of the