A rationale, also called superhumerale (from Latinsuper, "over", and [h]umerus, "shoulder"; thus a garment worn "over the shoulder[s]"), is a liturgicalvestment worn exclusively by bishops mostly in the Roman Catholic Church. It is mainly characterized as a humeral ornament – yet also adorning chest and back – and is worn over the chasuble. The term rationale originates from a Latin translation of the Ancient Greek λόγιον logion for the Hebrew חֹשֶׁן hoshen by St. Jerome, referring to the sacred breastplate worn by the High Priest of the Israelites, according to the Book of Exodus.
During the Middle Ages it was worn by several Bishops, primarily in the Holy Roman Empire, as far spread as Regensburg, Prague and Liège. Its use largely died out in the 13th century, although there is evidence that it was worn at Reims until the 16th century. Some rationales can be found preserved at Eichstätt, Bamberg and Regensburg. The earliest pictures of rationales that exist are two pictures of Bishop Sigebert of Minden, a miniature and an ivory tablet, which were both incorporated in a Mass Ordo belonging to the Bishop.[1]
The only Bishops who wear rationales in the 21st century are:
^ ab"Rationale". The Catholic Encyclopedia. Vol. XII. New York: Robert Appleton Company. 1 June 1911.
^Since 1165, whenever the bishop of Toul officiated pontifically, he wore an ornament called surhumeral, or rationale, a sort of pallium covered with precious stones, which decoration he alone of all the bishops of the Latin Church wore. A brief of 16 March 1865, restored this privilege to the bishops of Nancy and Toul.