Defending Probabilism: The Moral Theology of Juan Caramuel (review)

Long considered to be an outmoded intellectual tradition, late-Scholastic moral thought is currently enjoying a renewed and, as it appears, sustained scholarly interest. To a large extent, this new interest has been kindled by the emergence of a modernized kind of case ethics, which resulted from a serious reflection on, and discussion about, the methods to be used in moral problem-solving. In this debate, the question of moral certitude and incertitude played—and continues to play—a crucial role. Following the lead of Aristotle, several ethicists have insisted on the fact that ethics is not a science that defines absolutely certain and universally applicable principles, but rather is a form of practical wisdom dealing with a multitude of particular concrete situations that leaves room for moral doubt and difference of opinion.

It is precisely between the two poles of doubt and certainty that the field of the early-modern moral theologian and casuist was situated. There exists a dubium, a moral problem about which the conscience doubts or moves in uncertainty. As absolute certainty is impossible to achieve in matters relating to human action, a person’s conscience can never be absolutely sure. At best, the moral theologian formulates an opinion that is so probable that it may be regarded as “certain”—that is, “practically sure,” from a moral point of view. In other cases, however, uncertainty remains. The theologian is only able to formulate solutions that, at most, can be termed probable or likely. At the speculative level, doubt remains. Anyone acting on the basis of such a probable opinion acts with a “probable conscience.” However, is the probable opinion of the theologian sufficient to dispel practical doubt? May one act on the basis of a probable opinion, even if the opposite opinion is more probable, that is to say, supported by stronger arguments or more authorities?

Following the lead of earlier generations of Catholic moral theologians, the Spanish Cistercian monk Juan Caramuel y Lobkowitz (1606–82) felt that one could—a “broad” or lenient standpoint firmly rooted in the so-called doctrine of probabilism. The Spanish Dominican friar Bartolomé De Medina (1528–81) is commonly believed to have first formulated this doctrine, but many other moral theologians were involved in its development. It continued to be defended long after it had become a major target of Jansenist attacks around the middle of the seventeenth century. In her elegant monograph Defending Probabilism, Julia Fleming deals with Caramuel’s contributions to the heated debate on probabilistic reasoning that created a deep split in the Catholic world for many decades to come. Attempting to correct the caricature of Caramuel as an unduly laxist theologian, Fleming has taken into account a rich variety of texts to trace important changes in Caramuel’s views on probabilism. After an introductory chapter that sketches Caramuel’s life and work against the background of ecclesiastical history and the history of moral theology, Fleming engages in a penetrating analysis of Caramuel’s early treatments of probabilism in his In Divi Benedicti Regulam (1640) and the Theologia Moralis Fundamentalis (1652). These texts were quite remarkable experiments in argumentation in favor of probabilism. At the same time, however, they equipped Caramuel’s opponents with the ammunition for their unrelenting attacks against probabilism and Caramuel’s theory and practical use of it. Those attacks forced Caramuel to ponder the matter more thoroughly. His reflections were published in 1662 in the epistolary treatise Apologema, which was intended to explain and defend probabilism against its critics. As the Apologema was placed on the “Index of Forbidden Books,” Caramuel felt compelled to find a new means of explaining and defending probabilism. As Fleming convincingly demonstrates in chapter 6, Caramuel’s treatise Dialexis de Non-Certitudine (1675) contains a strikingly different approach to the problem of probabilistic reasoning—an approach that centers around the new concept of non-certitudo and is...