AVENDAÑO, DIEGO de. – Jesuit theologian and canonist, born in Segovia (Spain) in 1594, died in Lima (Peru) on 31 August 1688. After studying philosophy in Seville, he went to Peru in 1609 with the famous jurist Solorzano Pereira and entered the Society of Jesus in Lima in 1612. After completing his theological studies, he taught rhetoric and humanities in Lima, philosophy in Cuzco, theology at the university of Chuquisaca (today Sucre), and
at the Colegio Máximo of S. Paolo in Lima. He was subsequently assigned to administration and became rector at Chuquisaca, vice-rector at Cuzco, rector of the Colegio Máximo of Lima, vice-provincial (1661) and provincial (1663) of the Jesuits in Peru, and once again rector in two houses in Lima, until 1672. He was then able to devote himself to preparing his works, until old age brought this to an end (1685).
He wrote: Epithalamium Christi et Sacrae Sponsae, seu explanatio Psalmi XLIV, Lyon 1663; Amphitheatrum misericordiae seu expositio Psalmi LXXXVIII, Lyon 1666; Problemata theologica, 2 vols., Antwerp 1668. But his principal work is the Thesaurus indicus, seu generalis instructor pro regimine conscientiae in iis quae ad Indias spectant, 6 vols., Antwerp 1668–86 (vols. III–VI are «auctaria»); vol. VI is sometimes issued separately under the title: Cursus consummatus. The work lacks somewhat an organic plan and at times precision, but its merit lies in having applied the general principles of Catholic morality and canon law to the particular cases of the West Indies; it has been described as an «encyclopedia for missionary pastoral work and for missionary and colonial law» (Streit). A. left other works in manuscript, such as the Litterae annuae of the Jesuit Province of Peru for the years 1662–65, obituaries of several Jesuits, and a treatise entitled Mysterium Fidei.