Theresa, Or Teresa, Saint, a Spanish mystical writer, born in Avila, March 28, 1515, died at Alba, Oct. 4, 1582. She was called Teresa de Ahumada (her mother's family name) till August, 1562,' when she assumed that of Teresa de Jesus. At the age of 20 she entered the order of Carmelites in a convent of her native town, in which she remained 27 years. She then founded a reformed branch of the Carmelites (Barefooted Carmelites), sometimes called after her Theresians. During her life 29 convents of the reformed order were established, and in the 18th century it counted about 2,000 members in six provinces, in Spain and Spanish America. She was beatified by Pope Paul V., April 24,1614, and canonized by Gregory XV., March 22, 1622, her feast being fixed on Oct. 15. Theresa described the internal struggles and aspirations of her heart and her frequent mystic visions in ascetic treatises and letters, which are among the most memorable documents of the mystic literature of the Roman Catholic church, while their excellence of language and style has secured for them a place in the classic literature of Spain. Five of them are extant: Discurso relation de su vida, written in 1562; El camino de la perfection, prepared in 1563 as a guide for the nuns of her reformed order; El I'ibro de las fun-daciones, an account of the convents founded by her; El Castillo interior, ό las moradas, written in 1577, and the most celebrated of her mystic works, in which she portrays in glowing colors the gradual progress of the soul to the seventh heaven, the celestial castle of Christ, her spouse; and Santos conceptos de amor de Dios, the original of which she burned in obedience to her confessor, but which has been preserved from a copy taken by one of the nuns.

The original manuscripts of the first four works are preserved in the library of the Escurial. The first complete edition appeared at Salamanca in 1587, and a recent one, edited by Ochoa, at Paris in 1847 (Tesoro de las obras misticas de Santa Teresa de Jesus). A collection of letters of St. Theresa, addressed to dif-ferent persons, was published at Saragossa in 1658. The abbe Migne edited a complete collection of her works in French (4 vols., Paris, 1840-'46), and they have been translated into most other European languages. A French translation from the original manuscripts was published by Pere Marcel Bouix (3 vols. 8vo, Le Mans, 1852-'6). Among the many lives of rSt. Theresa are those of Ribera (Salamanca, '1590; French by Pere Bouix, Paris, 1865), the Bollandist Vandermoere (Brussels, 1845), and Maria French (London, 1875).