On Casuistry

Le grand docteur sophiste, 1886 illustration of Gargantua by Albert Robida,
expressing mockery of his casuist education

From Wikipedia:

Casuistry (/ˈkæzjuɪstri/ KAZ-ew-iss-tree) is a process of reasoning for resolving an ethical dilemma (moral problem) either by extracting or by extending abstract rules from a particular case of conscience, and reapplying those abstract rules to other, different ethical dilemmas.^[1] Casuistry is a method of reasoning common to applied ethics and jurisprudence. Moreover, in philosophy, the term casuistry is a pejorative criticism of the use of clever but unsound reasoning, especially in ethical questions, as in the case of sophistry.^[2] As a method of reasoning, casuistry is both the:

Study of cases of conscience and a method of solving conflicts of obligations by applying general principles of ethics, religion, and moral theology to particular and concrete cases of human conduct. This frequently demands an extensive knowledge of natural law and equity, civil law, ecclesiastical precepts, and an exceptional skill in interpreting these various norms of conduct ...^[3]

Etymology

The term casuistry and the noun "casuist" date from 1600 and derive from the Latin noun casus, case, as used in the phrase a "case of conscience", and the usual sense of the usage was pejorative.^[4]

History

Casuistry dates from Aristotle (384–322 BC), and the peak of casuistry was from 1550 to 1650, when the Society of Jesus (the Jesuits) used casuistic reasoning, particularly in administering the Sacrament of Penance (or "confession").^[5] The term became pejorative following Blaise Pascal's attack on the misuse of the method in his Provincial Letters (1656–57).^[6] The French mathematician, religious philosopher and Jansenist sympathiser attacked priests who used casuistic reasoning in confession to pacify wealthy church donors. Pascal charged that "remorseful" aristocrats could confess a sin one day, re-commit it the next, then generously donate to the church and return to re-confess their sin, confident that they were being assigned a penance in name only. These criticisms darkened casuistry's reputation in the following centuries. For example, the Oxford English Dictionary quotes a 1738 essay^[7] by Henry St. John, 1st Viscount Bolingbroke, to the effect that casuistry "destroys, by distinctions and exceptions, all morality, and effaces the essential difference between right and wrong, good and evil".^[8]

From Claude: 

Good question, and it gets at something that's often flattened into caricature. Let me unpack it a bit.

Who Escobar was, and what casuistry actually was

Antonio Escobar y Mendoza was a 17th-century Spanish Jesuit, and casuistry (from Latin casus, "case") was the branch of moral theology that worked out how general moral and church law applied to specific, complicated real-life situations. This wasn't fringe or disreputable work — it was the standard method by which confessors were trained to hear confession and assign penance. A priest couldn't just cite the Ten Commandments; he needed guidance on messy particulars: Is a soldier who kills in an unjust war guilty? What if a merchant genuinely doesn't know if a price is fair? What if someone lies to protect an innocent person from murderers?

Escobar's most famous work, the Summula Casuum Conscientiae (and later a massive compendium of moral theology), was essentially a reference manual — organized like a legal casebook — cataloguing opinions from many theologians on thousands of these specific scenarios.

Who used this, and why

The audience was mainly confessors and the penitents they served, especially among the educated and propertied classes — merchants, nobles, officials, soldiers — people whose lives involved contracts, oaths, dueling, inheritance, tax evasion, and political intrigue, where "is this a mortal sin?" wasn't obvious. Casuistry was, in a real sense, a pastoral technology: a way of applying mercy and nuance rather than blanket condemnation, and of making confession usable for people living complicated lives.

Were they serious? Yes — but with a specific intellectual habit that got them into trouble

The theologians were serious scholars, not cynics gaming the system for its own sake. But two features of their method created the opening for real abuse:

1. Probabilism. This was the load-bearing doctrine: if a credible theologian had argued a position was permissible, a person could follow that opinion even if the stricter, "safer" opinion was more likely correct — because compelling one's conscience beyond what could be proven was itself a kind of tyranny. That's a defensible principle in itself. But it created a market logic: if enough authors, however obscure, had endorsed some permissive reading, you could always find one on file for practically any act.

2. Extreme granularity and hypothetical reasoning. Casuists loved constructing precise fact patterns and working out the boundary conditions — since a general rule always has edge cases, that's not absurd on its face. But writers could push this to constructing edge cases that were transparently designed to swallow the rule, rather than illuminate it.

So was this "twisting logic to avoid responsibility"? — largely, yes, in its later/lesser exponents

Your instinct is basically what critics said at the time too, most devastatingly Blaise Pascal in his Provincial Letters (1656–57), a Jansenist-aligned satire that mocked exactly this — quoting (often selectively and polemically) casuist opinions that let a nobleman kill over a slight insult, or let a servant assist a crime "under duress," and so on — several of which resemble propositions actually condemned in 1679. Pascal's charge was that "probable opinion" had become a tool for professional moral engineers to manufacture permission for whatever a well-off penitent wanted absolution for, dressed up in scholastic Latin.

It's worth distinguishing three tiers here, though:

• Serious, mainstream casuistry — genuinely useful moral reasoning about hard cases, still recognizable in things like just-war theory or modern applied/medical ethics, which is itself a revival of the casuistic method.
• Escobar and compilers like him — often unfairly flattened into "the Jesuit villain" by Pascal, when in fact they were mostly cataloguing existing opinions rather than personally inventing the most outrageous ones (though Escobar did become a byword — the French verb escobarder meant "to equivocate").
• The genuine laxists — writers like Bauny, Diana, and others named in that Catholic Encyclopedia excerpt — who pushed probabilism toward absurd or self-serving conclusions, and who Rome itself eventually moved against, first under Alexander VII in 1665–66 and then more sweepingly under Innocent XI in 1679.

So the condemnation you started with wasn't the Church attacking casuistry as such — it was the Church's own internal correction of a method it still endorsed in principle, once it judged that certain practitioners had turned a tool for pastoral mercy into a technique for consequence-free sin. That's also, not coincidentally, why "Jesuitical" became an English insult for slippery reasoning — even though most Jesuits, and most casuists generally, were doing something closer to careful applied ethics than to the caricature.