Paolo Sarpi (commonly known as Fra Paolo), an Italian historian, born in Venice, Aug. 14, 1552, died there, Jan. 14, 1623. He studied for 12 years in a convent of Servites, became a member of that order in 1565 (exchanging his baptismal name of Pietro for that of Paolo on his solemn profession in 1572), completed his course of philosophy and theology at Mantua in 1570, was appointed professor of theology in the university there, and afterward at Venice. He became provincial of his order in 1579, and went to Rome to draw up new constitutions for the Servites. In 1585 he was sent again to Rome as procurator general, and was taken into favor by Sixtus V. He studied natural science, and when recalled to Venice in 1589 he drew up an account of his discoveries in physics. According to Gri-sellini, Sarpi had discovered the circulation of the blood, and had been the first to observe the dilatation and contraction of the pupil of the eye, the effect of pure air injected into the lungs in case of asphyxia, and the various phenomena of the inclination of the magnetic needle. Although noted for austerity of life, the independence with which he expressed his opinions on religious matters caused him to be suspected by the Venetian inquisitors, and to be refused two episcopal sees which he had solicited.

Pope Paul V., having vainly requested the abrogation of a law of Venice which he deemed contrary to the freedom of the church, threatened to lay the republic under an interdict. Sarpi thereupon published a pamphlet in which he assailed the papal pretensions. On Jan. 28, 1605, he was appointed state canonist, and in 1606 issued a Trattato dell' interdetto, in which he exhorted the Venetians to disregard the threatened interdict. Consulted by the Venetian government on the most important matters of public policy, and allowed the free use of the state archives, Sar-pi published elaborate answers, and Come deb-ba governarsi la republica veneziana per avere il perpetuo dominio. These works have been condemned as advocating an odious system of duplicity and oppression. At the same time their author strenuously promoted an alliance between Venice and the new Dutch republic, while stimulating his fellow citizens to hostility toward the court of Rome. He was denounced as a schismatic and a Protestant, and an attempt was made upon his life, Oct. 5, 1607. He is now best known by his " History of the Council of Trent" (Istoria del con-cilio tridentino, fol., London, 1619; 4 vols. 8vo, Florence, 1858; Latin translation, London, 1620; English translation, 1629 and 1676). Another principal work of Sarpi was his Istoria dell' interdetto (4to, Venice, 1624; translated into French and Latin). The best complete edition of his writings was published in Naples (24 vols., 1789). His life has been written by the Italian liberal A. A. Bianchi-Giovini (2 vols., Zürich, 1836), and by A. G. Campbell, from original manuscripts (Florence, Turin, and Rome, 1875). An account of the controversy of Sarpi with the pope and the Jesuits is given by T. Adolphus Trollope in his "Paul the Pope and Paul the Friar" (London, 1860).