The author most likely had the Elements of Theology before him in an Arabic translation. The book itself, it seems, demands this assumption. Other evidence for the existence of an Arabic translation of the Elements of Theology, however, cannot be produced. The cited note by Haji Khalifa is not proof. Genesis of this note 42. Whether the "Book of Theology" which the Arabic bibliographers attribute to Proclus is the Elements of Theology must remain an open question 45. In any case, one cannot conclude from this mention of the title alone the presence of an Arabic text of the work itself 46.

Under the prevailing circumstances, the investigation of the origin of our book is dependent on determining the earliest traces of the book itself. In Arabic literature, it is mentioned only very rarely. The bibliographic lexicon of Ibn Abi Ussaibi'a 48. Ibn Sab'in's letter of reply to Emperor Frederick II 49.

A more precise answer to the question of the book's origin is not possible for the time being 50. The author was a faithful Muslim who may have lived in the ninth century, perhaps beyond the Euphrates 51.

The statements of Albert the Great regarding the origin of our book, which are to be discussed in more detail on a later occasion 53. The assumption of Alfarabi's authorship, first testified by Giles of Rome 55. Other alleged authors 57.

The Arabic text together with German paraphrase. pp. 58—118.

Part Two.

The Latin translation of the book de causis used by the Scholastics.

The origin of the Latin translation. pp. 121—151.

Neither Dominicus Gundissalinus nor John Avendehut (John of Seville) translated our book into Latin 121. The statements of Albert the Great (De causis et processu uniuersitatis lib. II. tract. 1. c. 1) regarding the origin of the book 126. The Jew David (Dauid Judaeus quidam), described by Albert as the author and not as the translator, is an entirely unidentifiable personality whose claim to historical truth appears all the more doubtful as Albert's further statements are in part highly enigmatic and in part demonstrably completely incorrect 128.

The translator of our book into Latin is rather Gerard of Cremona. The sources concerning him 135. His biography 138. His translation activity 139. The liber Aristotelis de expositione bonitatis purae Aristotle's Book on the Exposition of Pure Goodness translated by Gerard is our book 140. He translated it in Toledo 142, in the years 1167—1187 142, from the Arabic 145.