(p.101) The term “casuistry” is derived from cams, Latin for “case,” and refers to the study of individual “cases of conscience” in which more than one settled moral principle (or perhaps none) applies. More broadly, casuistry is the use of the “method of cases” in the attempt to bring ethical reflections to bear on problems requiring the decision and action of some moral agent. A casuist is thus one who is trained to provide such counsel. Accordingly, casuistry is a branch of applied ethics. Since the seventeenth century, however, the term has often been used in a derogatory sense, as though casuistry were a species of sophistical reasoning by means of which almost any conduct could apparently be deemed permissible, provided only that one is ingenious enough in exploiting exceptions and special circumstances.
For the casuist, the solution to a morally problematic case is obtained by comparing and contrasting its features with various paradigm cases whose moral status is settled. Solutions to the problem cases rely both on moral principles or maxims (p.102) that express the received wisdom concerning such paradigms and on analogies to them. The plurality of principles is a source of their actual or potential conflict, but their general reliability otherwise is taken for granted. Hence, casuistry as a method of practical reasoning tends to rely on some form of intuitionism as well as on some set of moral norms more or less beyond dispute.
The governing idea of casuistry is expressed in the second order maxim that “circumstances alter cases.” As Thomas Aquinas wrote (1275): “The human act ought to vary according to diverse conditions of persons, time and other circumstances: this is the entire matter of morality.”1 The method of cases is designed to take these “diverse conditions” into account. This is to be contrasted both with mechanical application of rigid rules of conduct and with the attempt to ground moral decision making in some grand theory of the good or the right.
Casuistry is a natural outgrowth of three features of Aristotle's Nichomachean Ethics (ca. 330 B.C.E.). First, Aristotle took it for granted that persons have a grasp of the principles of right conduct, based on their socialization as members of a human community. He also argued that it is impossible to secure theoretical precision in practical matters, and so ethical reasoning should not aspire to the rigor appropriate to a true science. Finally, practical wisdom (Aristotelian phronesis) is essential to right conduct; it can be obtained only by critical reflection on actual experience in confronting the diverse problems that human life presents.
(p.103) Casuistry (although not under that name) was taught for centuries as part of Greco-Roman rhetoric. A standard exercise required the student to propose and defend a solution to a practical problem by means of arguments and counterarguments in which various moral principles and solutions to analogous cases would be integrated for maximum persuasive effect. Cicero's De Officiis (ca. 44 B.C.E.) provided later generations with a partial catalogue of famous cases in which either a conflict of duties or a conflict between duty and expediency needed to be resolved. Thus, later casuistry can be seen as a systematic approach to ethical problems derived from Ciceronian rhetoric.
Rabbinic pilpul and Roman common law also influenced moral casuistry independently of classical rhetoric. Weighing relevant principles, arguing from paradigm cases, distinguishing apparently contrary conclusions in prior cases—all are familiar methods both in the resolution of disputes through the common law and in Talmudic commentary and interpretation. Among Christians, the need to reconcile the Mosaic law with the examples and counsels in the Gospels in order to provide guidance for daily life made the development of casuistical reasoning by the clergy all but inevitable. These legal and pastoral elements were combined in the development of canon law and penitential discipline during the Middle Ages.
From 1200 through 1650, the teaching and practice of casuistry flourished in Europe. The Summa de sacramentis et animae conciliis (ca. 1191) by Peter Cantor of Paris was perhaps the first true casuistic treatise. With the founding of the Society of Jesus in 1534, casuistry dominated pastoral (moral) theology. Treatises in which hundreds, even thousands, of cases were presented and discussed became commonplace. One of the (p.104) most influential was the Enchiridion (1556) of Martin Navarrus. In 1600, the Jesuit Juan Azor published his Institutionum Momlium, nearly four thousand pages long, in which he declared “all questions of conscience are briefly treated.” The monumental Resolutiones morales (1629–59) by Antonius Diana, “the Prince of Casuists,” discussed some 20 thousand cases in 10 volumes.
A principal factor in the decline of casuistry, leading to its worst abuses, was the doctrine that if a practical opinion or counsel is probably true, it is permitted to follow it, even though it is more probable that the opposite opinion is true. This thesis, known subsequently as “probabilism,” was first enunciated by Bartolome Medina in 1577. Hitherto, the predominant view had been the obvious one that where there were divergent opinions on how to act, differing in their likelihood of being correct, the path of prudentia (practical reason) was to follow the more probable opinion. This was the via tutior, the “safer way.”
In practice, probabilism often meant that if persons wanted to act in a manner contrary to the best counsels, they were free to do so (that is, if they did not violate any moral duty), provided there was some plausible ground for doubting that one really was forbidden to act in the desired manner. Such a ground could be either “extrinsic,” based on the opinion of some authoritative moral thinker, or “intrinsic,” based on a good reason or argument, whatever its source.
The underlying purpose of probabilism has been said to be “to lighten the burden of conscience on the unscrupulous and troubled.”2 But the less scrupulous could use probabilism to serve selfish interests, thus deservedly incurring the charge of (p.105) “laxism” and thereby bringing the very practice of casuistry into disrepute.
The disappearance of penitential discipline under Protestantism, combined with the criticism of laxism from within the Roman church itself, weakened the practice and authority of casuistry.3 But the truly fatal blow was delivered by Blaise Pascal in his Lettres Provinciales (1656–57). As a Jansenist, convinced that the path of Christian rectitude involves strict compliance with the pure spirit of the Gospels, Pascal was hostile to the probabilist casuistry taught by the more worldly Jesuits. Writing anonymously, he mocked it unmercifully and exposed to ridicule the moral laxity of its diverse counsels.
However unfair a caricature of the actual methods and principles of casuistry Pascal's attack may have been, it succeeded in discrediting the entire practice. Henceforth, little more than faint echoes of casuistry would be found in the ethical writings of the leading philosophers outside the clerical tradition, such as Kant and J. S. Mill. By the end of the nineteenth century, with ethical pluralism and intuitionism on the defensive generally, Henry Sidgwick could write five hundred pages on The Methods of Ethics (1874) and dismiss casuistry in a sentence.
Thanks to the growing importance in the 1970s of applied ethics and of professional ethics in particular, a “new casuistry” has appeared in which the old “method of cases” has been revived and modified.4 (p.106)
(1.) Quoted in Albert R. Johnson and Stephen Toulmin, The Abuse of Casuistry: A History of Moral Reasoning, Berkeley, University of California Press, 1988, p. 135. My remarks in this essay are much indebted to this volume.
(2.) Johnson and Toulmin, The Abuse of Casuistry, p. 168.
(3.) For further discussion of casuistry during this period, see Edmund Leites, ed., Conscience and Casuistry in Early Modern Europe, Cambridge, Cambridge University Press, 1988.
(4.) See, for example, Christopher W. Gowans, ed., Moral Dilemmas, New York, Oxford University Press, 1987.