A distinguished cardinal and author, b. of an old French family at Mondovi, in Piedmont, 19 October, according to some 10 October, 1609; d. at Rome, 28 October, 1674. Although his father favoured a military career for him, after passing some years at a nearby Jesuit college he entered the Cistercian monastery at Pignerola, where, as also later at Rome, he pursued his studies with exceptional success. He laboured for fifteen years at Turin, then as prior at Asti and as abbot at Mondovi, and in 1651 was called to preside over the whole congregation. During his seven years of official life in Rome he modestly declined all further honours, at one time even refusing the Bishopric of Asti. He welcomed the expiration of his third term in the scholar's hope that he would be allowed to enjoy a life of retirement and study, but his intimate friend, Pope Alexander VII, wishing to honour his learning and piety, made him Consultor to the Congregation of the Index and to the Holy Office. In 1669 he was created cardinal, and then the beauty of his character was fully revealed; there was no change in his extremely simple manner of life, and every year he donated his surplus revenue to the needy priests of the Missionary College at Rome.

His best known ascetical works are: "Via Compendii ad Deum" (1657); "Principia et documenta vitæ Christinæ (1673); "Manuductio at cælum" (1658); and "Horologium Asceticum" (Paris, 1676). The "Manuductio" is often compared to the "Imitation of Christ" on account of simplicity of the style in which the solid doctrine is taught. It has always been extremely popular. Besides passing through fourteen Latin editions in four decades, it has been translated into Italian, French, German, Armenian and Spanish. The latest translation is in English by Sir Robert L'Estrange (A Guide to Eternity, London 1900). Shortly after his ordination he collected together some of the most beautiful passages in the Fathers on the August Sacrifice of the Mass, and later published them in a booklet, which with certain additions grew into his "De Sacrificio Missæ", a useful Mass book. In addition he composed several unpublished works, known as "Ascetici", for the instruction of members of his own order.

But his fame does not rest solely on the devotional writings. He was a deep student of antiquity, and so successful in treating of the use of the Psalter in the Christian Church (De Divinâ Psalmodiâ, Paris, 1663) that Cardinal Pallavicini urged him to undertake the history of the Sacrifice of the Mass. Realizing the magnitude of the task he at first declined, but finally set to work and after more than seven years' labour brought out his famous work familiar to all students of liturgy: "De Rebus Liturgicis" (Rome, 1671). It is a veritable encyclopedia of historic information on all subjects bearing on the Mass, such as rites, churches, vestments, etc. Not least remarkable about these volumes, besides the wealth of material gathered together, are the classic purity, the manly vigour, and the charming simplicity of the Latin style. The best edition of this work is by Robert Sala (Turin, 1747-53), who also in 1755 brought out a very interesting volume of Bona's letters. The first of many editions of his complete works was published at Antwerp in 1677.

FABRONI, Vitæ Italorium doctrina excellentium, etc. (Pisa, 1778-1805), XII, 7; MAZZUCHELLI, Gli scrittori d'Italia (Brescia, 1753-63, II; Part III, 1515); BERTOLOTTI, Vita Joannis Bona (Asti, 1677); GOUJET, Vie du cardinal Bona in the French translation of De principiis vitæ Christianæ (Paris, 1728); DUPIN, Bibliothèque des auteurs ecclés, du XVIIe siècle (Paris, 1708), III, 56.

Leo F. O'Neil.