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Orobio de Castro, Isaac


OROBIO DE CASTRO, ISAAC (Balthazar ; 1620–1687), philosopher and physician, born in Braganza, Portugal, of Marrano parentage. After studying medicine and philosophy in Alcalá de Henares, Orobio became a leading physician and professor of medicine in Seville and professor of metaphysics at Salamanca. In Alcalá he was the student of the Carmelites and the Franciscans. He was subsequently arrested by the Inquisition and charged with secretly practicing Judaism. Orobio was incarcerated for three years, tortured, and finally confessed. Upon his release, he fled to France, where he became professor of pharmacy at Toulouse. In 1662 he moved to Amsterdam where he joined the Jewish community, changed his name to Isaac, and practiced medicine. During the 17th century he was one of many Conversos who returned to Judaism in communities which were mainly established by such people. Orobio, who soon became one of the leading intellectual figures among the Spanish and Portuguese refugees, wrote poetry and philosophical treatises in defense of Judaism.

Orobio experienced a variety of religious and cultural encounters before he joined the Amsterdam Portuguese Jewish community. In Braganza he lived in fear of the Inquisition. From Portugal his family moved to Andalusia where he learned to live a double life. In Spain he moved from one place to another in search of a safe haven. In France he was able to reveal his Jewish identity and decided to move to Amsterdam.

His first important work consists of letters against the rationalistic defense of Judaism in answer to Alonso de Cepeda of Brussels. Among his best-known works is Certamen philosophicum propugnatae veritatis divinae ac naturalis (1684), a rationalistic and scholastic attempt to refute the philosophy of *Spinoza, and like Spinoza's Ethics written in a series of theorems. The work was also published in Fénelon's Refutation des erreurs de Benoît de Spinosa (1731). Orobio became acquainted with the Dutch Protestant liberal preacher, Philip van Limborch, in Amsterdam, who, impressed by Orobio's accounts of how the Spanish Inquisition functioned, used them as the chief case history in his Latin history of the Inquisition. Limborch, however, was disturbed by Orobio's anti-Christian arguments. They held a debate in the presence of John Locke which was published in 1687 (Pauli a Limborch de Veritate Religionis Christianae, amica collatio cum erudito Judaeo) along with the first issue of Uriel da *Costa's autobiography. Locke wrote a long review of the debate for the Bibliothéque universelle (vol. 7). Orobio's major anti-Christian work is Prevenciones divinas contra la vana idolatria de las Gentes; portions of this were published by Baron d'Holbach in French, as part of his anti-religious campaign, under the title Israel vengé (London, 1770). A greatly toned-down version, translated by Grace *Aguilar, was printed in English in 1842 as Israel Defended.

Most of Orobio's works were not published but circulated in manuscript among the European Jewish communities. The largest collection exists in the Biblioteek Ets Ḥayyim in Amsterdam; others are in the Rosenthaliana collection in Amsterdam, in Paris, London, Oxford, and New York. An acute metaphysician, Orobio de Castro utilized materials from the Spanish scholastics of the 16th and 17th centuries to defend Judaism against freethinkers like Juan de *Prado and Spinoza, against orthodox Christians, and against religious liberals like Limborch. Certain of Orobio's arguments against Christian theology are very close to some of Spinoza's against the plurality of substance. He made interesting efforts to provide a philosophical justification for Judaism in 17th-century terms, and, in contrast to Spinoza, to show the compatibility of reason with the traditional faith.


Kayserling, Bibl, 81–83; Graetz, in: mgwj, 16 (1867), 321–30; Orobio de Castro, La Observancia de la Divina Ley de Mosseh, ed. by M.B. Amzalak (1925), xviii–xxxix; J. de Carvalho, Oróbio de Castro e o espinosismo (1937); I.S. Revah, Spinoza et le Dr. Juan de Prado (1959), 84–153; Roth, Marranos, index. add. bibliography: G. Nahon, in: Yod, 26 (1987), 57–62; Y. Kaplan, From Christianity to Judaism: The Story of Isaac Orobio de Castro (1989).

[Richard H. Popkin /

Yom Tov Assis (2nd ed.)]

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