Note 13 — Book the First

The first Pontiff of this name, fifth in succession from the Lord St. Peter P.P., is named in the Canon of the Mass as Xystus [Ξυστός, cf. Xanthus (Ξάνθος)]. The same form Xystus occurs in the Kalendarium, and, in fact, in all officially issued liturgies; and is adopted also in the authorised English version of the Liturgy. The word Sixtus does not appear to be a Latin word at all, and is not in Andrew’s Latin-English Lexicon. It most likely is a debased corruption from Xystus, when Latin liquefied into the Italian Sisto.