ROSAS, JUAN MANUEL DE (1793-1877), tyrant of Buenos Aires and outstanding figure in the history of Argentina, was born on March 3o, 1793, in the city of Buenos Aires, where his father took an active part in defeating the English in 1807. Juan Rosas received a meagre education and at an early age left his parents. For a time he subsisted as a vaquero, or cowboy, but later purchased a cattle-run of his own, Los Cerrillos. The an archical state of the country since winning its independence enabled him to obtain leave to arm his cowboys, whom he made the most efficient fighting force in the country. By adroit use of this weapon, and by strict attention to his own interest, he rapidly became the dominant figure in the province of Buenos Aires. As governor of the province from 1829 to 1832, he gave it the first peace it had known in 20 years, so that in 1835, after a brilliant Indian campaign, he was unanimously elected dictator of Buenos Aires, and held that position until 1852. Throughout his regime, he waged a war of extermination against the leaders of the interior provinces who sought to combine against him or to set up for themselves as independent rulers. In spite of the continual com binations, domestic and foreign, in which this policy embroiled him, and of wars with Paraguay, Chile, Peru, Brazil, Uruguay, France and England, from which he had scarcely a moment's free-. dom, he broke the powers of the caudillos and upheld the suprem acy of Buenos Aires in the country. In 1852 he was finally over thrown by a coalition of his neighbours and disaffected generals. He took refuge in England, at Swaythling, near Southampton, where he lived in poverty until his death on March 17, 1877.
(W. B. P.) ROSCELLINUS (RUCELINUS or ROUSSELIN) (C. 1050--C. 1122), often called the founder of Nominalism (see SCHOLASTI CISM), was born at Compiegne (Compendium). He studied at
Soissons and Reims, was afterwards attached to the cathedral of Chartres, and became canon of Compiegne. It seems most probable that Roscellinus was not strictly the first to promulgate nominalistic doctrines; but in his exposition they received more definite expression, and, being applied to the dogma of the Trinity, attracted universal attention. Roscellinus maintained that it is merely a habit of speech which prevents our speaking of the three persons as three substances or three Gods. If it were otherwise, and the three persons were really one substance or thing (una res), we should be forced to admit that the Father and the Holy Spirit became incarnate along with the Son. Roscellinus seems to have put forward this doctrine in perfect good faith, and to have claimed for it at first the authority of Lanfranc and Anselm. In 1092, however, a council convoked by the archbishop of Reims condemned his interpretation, and Roscellinus, who was in danger of being stoned to death by the orthodox populace, recanted his error. He fled to England, but having made himself unpopular by an attack on the doctrines of Anselm, he left the country and repaired to Rome, where he was well received and became reconciled to the Church. He then returned to France, taught at Tours and Loc-menach (Loches) in Brittany (where he had Abelard as a pupil), and finally became canon of Besancon. He is heard of as late as 1121, when he came forward to oppose Abelard's views on the Trinity.
Of the writings of Roscellinus, nothing is preserved except a letter to Abelard, mainly concerned with the doctrine of the Trinity (ed. J. A. Schmeller, Munich, 185o) . See F. Picaret, Rosselin, philosophe et theologien (1896), and authorities quoted under SCHOLASTICISM.