The word casuistry is derived from the Latin word for case — “causa”, referring to a particular occasion or to a legal case, and not “casus”, referring to a fall or accident.
One meaning is an approach to ethics which decides each ethical question on a case by case basis, with no overriding moral rules or principles. Such an approach is contrary to Catholic teaching, which has the love of God and neighbor as the fundamental rule of ethics, as well as various basic principles of ethics.
Another meaning is to begin with a particular instance, and then generalize that instance to cover other cases. This approach can fail because ethics is based on intention, moral object, and circumstances. Since intention and circumstances vary, it is not always correct to generalize from a few cases.
A third meaning is to justify sins by a clever and subtle, but false, reasoning, especially one that is legalistic, and devoid of love and mercy. Obviously, this approach is contrary to the Gospel.
But casuistry is not “the application of broad principles to concrete cases”. That is the opposite of casuistry.
What Pope Francis means by the term appears to be both the second and third meanings. He rebukes the critics of Amoris Laetitia by saying that their approach is casuistic. They begin with a particular instance of divorce and remarriage, where a previous valid marriage makes the current union adulterous, and then they assume that all other cases are the same. In fact, there are a range of different situations. In some cases, the previous union was invalid and the couple can obtain an annulment. In other cases, the divorced and remarried might be living in chastity, but remain together for the sake of the children. In still other cases, the couple might be in good conscience, by a sincere but mistaken conscience, so that they are still in the state of grace.
The critics of Amoris Laetitia are also casuistic in their reasoning because they use an approach which is legalistic, offering false reasonings which are devoid of love and mercy.
The assertion of Pope Francis that Amoris Laetitia is Thomistic has also been criticized. But Pope Francis is again correct. Saint Thomas Aquinas teaches that ignorance can sometimes remove or diminish the culpability of an objectively sinful act (Summa). And that is the main and much disputed point of Amoris Laetitia.
Cardinal Muller wrote the following in a preface to a book by Rocco Buttiglione, defending Pope Francis against the critics of Amoris Laetitia.
“The formal element of sin is the departure from God and his holy will, but there are different levels of gravity depending on the type of sin. Spirit’s sins can be more serious than flesh’s sins. Spiritual pride and avarice introduce into religious and moral life a more profound disorder than impurity resulting from human weakness. The apostasy of faith, the denial of the divinity of Christ weighs more than theft and adultery; adultery among married people weighs more than among the unmarried and, the adultery of the faithful, who know God’s will, weighs more than that of the unbelievers (cf. Thomas Aquinas, th. S. I-II q. 73; II-II q). Moreover, for the imputabilty of guilt in God’s judgment, one must consider subjective factors such as full knowledge and deliberate consent in the serious lack of respect for God’s commandments, which has as a consequence the loss of sanctifying grace and of the ability of faith to become effective in charity (cf. Thomas Aquinas S. th. II-II, q. 10 a. 3 ad 3).
This does not mean, however, that now Amoris laetitia art. 302 supports, in contrast to Veritatis splendor 81, that, due to mitigating circumstances, an objectively bad act can become subjectively good (it is dubium n. 4 of the cardinals). The action in itself bad (the sexual relationship with a partner who is not the legitimate spouse) does not become subjectively good due to circumstances. In the assessment of guilt, however, there may be mitigating circumstances and the ancillary elements of an irregular cohabitation similar to marriage can also be presented before God in their ethical value in the overall assessment of judgment (for example, the care for children in common, which is a duty deriving from natural law).”
So we can see from the above quote that Amoris Laetitia is Thomistic, and that the critics of the document have erred by refusing to take into account the factors that might make an objective mortal sin not also an actual mortal sin.
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