Liber introductorius

Liber introductorius (Classical Latin: [ˈliːbɛr ɪntroːdʊkˈtoːrɪ.ʊs], Ecclesiastical Latin: [ˈliber introdukˈtori.us]; The Introductory Book) is the collective name for a trilogy of books written by Scottish mathematician Michael Scot in the early 13th century. The trilogy concerns the art of divination. Because the work's prologue mentions the canonization of St. Francis of Assisi, it is likely that the assemblage was officially compiled after July 16, 1228 (i.e. the date of the aforementioned canonization).