  William's views are known mostly through references in contemporary works, especially those of Abelard. Though several of William's works have been identified, very few have been edited, and none has been translated into English. The Introductions — Introductiones dialecticae secundum Wilgelmum  (ISW)  and Introductiones dialecticae secundum magistrum G. Paganellum (IGP) — are very early works, possibly dating from William's arrival in Paris in 1094. Edited with these two Introductions are two brief discussions of media or loci, and the beginning of an early commentary on Porphyry, all likely by William (Iwakuma 1993; ISW is also in de Rijk 1967). These texts defend some of William's characteristic doctrines, but in 1094 the vocalist movement had not yet begun to exert any real influence in Paris, and so it is likely that he had not yet been forced to articulate his views in response to serious criticism.