MERCADO, TOMÁS DE

Dominican logician; b. Seville, date unknown; d. San Juan de Ulúa, Mexico, 1575. When he was very young, Mercado was taken to Mexico and received the Dominican habit in the Colegio de Santo Domingo of the province of Santiago in Mexico. There, after completing his studies, he was ordained on April 27, 1553. At the University of Mexico be excelled in theological studies under Fray Pedro de Pravia, an eminent master from Salamanca and the Colegio de Santo Tomas, Ávila. His superiors sent him to Spain, where at Salamanca he perfected his studies before being assigned to teach at the convent of Seville.

While there, he published his principal works, among them Commentarii lucidissimi in textum Petri Hispani (1571), a commentary on the principal dialectical work of Peter of Spain, Summulae logicales. Like Domingo de Soto, Mercado undertook the work to preserve the profound dialectical teaching of this illustrious 13th century logician. Mercado's commentary is a precise, complete, original, and vigorous exposition of the genuine logical doctrine of Aristotle's First Analytics and constitutes one of the most important dialectical treatises of the post-Tridentine scholastic revival. Logic is raised to the science of sciences, a foundation for the other sciences. In Dialecticam Aristotelis cum opusculo argumentorum (1571) is an original, exact Latin translation from the Greek of Aristotle's Logica major divided into chapters and texts, each followed by a twofold commentary, one explaining the text itself in precise, well-chosen words, the other inquiring into the truth of the question. The reason for a new version was the corrupted state of current, literary, Ciceronian versions so dear to the Renaissance, into which had also crept various nondialectical questions such as the analogy of being, the identity or distinction of being, and the categories. Mercado's restoration of the purity of the original Greek is an eloquent testimony of the high level of studies in the newly founded schools of Mexico where he received all his classical training. Suma de tratos y contratos, en seis libros (1569) was written for the merchants of Seville and is principally an ethicotheological work of the times with only a few introductory questions of philosophical interest, for example, on natural law, which reflects the intellectualism of Thomas Aquinas, and on justice, which reflects the influence of Domingo de Soto.

Bibliography: o. robles, "Fray Tomás de Mercado," Revista de filosofía 9 (Madrid 1950) 541–559.

[o. robles]