Atto of Vercelli, a learned theologian and canonist of the tenth century, son of the Viscount Aldegarius, and Bishop of Vercelli (924-961). In 933 he became Grand Chancellor of Lothaire II, King of France, and obtained from the royal gratitude donations and privileges for his see of Vercelli (Ughelli, Italia Sacra, IV, 769). Several of his writings were first published by the Benedictine D’Achery (1655-77) in his “Spicilegium” VIII, 1-137; 2d ed., 1723, I, 401-442, e.g.
Epistohe, Libellus de pressuris ecclesiasticis”, and “Canones rursus statutaque Vercellensis ecclesiae”. A complete edition was executed by Baronzo del Signore, in two folio volumes (Vercelli, 1768; P.L., CXXXIV, 27-834), inclusive of his lengthy commentary on the Epistles of St. Paul. In 1832 Cardinal Mai published eighteen sermons of Atto, and his curious “Polypticum”, or “Perpendiculum”, an abridgment of moral philosophy, “written in a mysterious and enigmatic way”. In his history of early medieval literature Ebert transfers to some Spaniard the authorship of this work, but Hauck defends the traditional view (Realencyk. f. prot. Theol., II, 214). His “Canones” are in great part a compilation of earlier ecclesiastical legislation, including the False Decretals. They contain, also, certain provisions of his own and are of value for the study of contemporary ecclesiastical life and manners in Northern Italy. He is sometimes known as Atto II; an earlier homonymous bishop of Vercelli flourished about the middle of the eighth century.
THOMAS J. SHEEHAN