Jesuits encouraged secular learning and scholarship among their members. You cannot offer the general public a university that teaches nothing but theology. Moreover, a knowledge of secular subjects is useful in getting a hearing (see Matteo Ricci and his astronomy at the Chinese Imperial Court). Jesuit missionaries made important contributions to the study of geography and non-Indo-European languages. One group of Jesuit scholars known as the Bollandists devoted themselves to hagiography (the historical and critical study of the biographies of saints), patiently collating sources and sifting fact from legend. Their work, concentrated in Belgium, has been going on since the early 1600's and is of importance to anyone interested in church history.
When Elizabeth came to the throne of England in 1558, she changed the language of worship from Latin to English. Many of her subjects grumbled, but they continued to attend services at their parish churches. In 1570, however, Pope Paul V excommunicated Elizabeth, declared her not the lawful queen but rather a suitable target for assassination, and told his followers in England not to attend their parish churches any more than they were compelled to, but rather to attend Latin Masses celebrated by priests loyal to Rome. Not unnaturally, Elizabeth regarded anyone celebrating a Latin Mass as a fomenter of treason and of plots to assassinate her. For many years thereafter (beginning in 1580) the Jesuit seminary at Douay in France sent a steady stream of priests (Englishmen who had been smuggled out of England, educated and ordained, and then smuggled back in) to England, and in smaller numbers to the rest of the British Isles, where they celebrated Latin Masses in secret, subject to death for treason if caught. About 70 were martyred.
Suppose that you are faced with a choice of actions, say between A and B. Sometimes you will be torn between those who say that you have a moral obligation to do A and not B, and those who say that you have a moral obligation to do B and not A. However, it often happens that what you want to know is: "Am I free to do either A or B as I prefer, or have I a moral obligation to do A?" (Naturally, you will usually be asking this question when you would rather do B.)
One answer, often very popular with those who are not going to be affected by the decision, is what is called Rigorism. Are you sorting your shirts into those that need to be washed and those that do not? Your mother will tell you: "If it's doubtful, it's dirty." The same applies to moral choices. If you are not sure whether it is okay to do something, be on the safe side and don't do it. If you are not sure whether that golf ball is a lost ball or just waiting for its owner to arrive, you can't go wrong by walking away and leaving it. If you are not absolutely sure that a certain expense qualifies as a tax deduction, then don't deduct it. If you are not absolutely sure that your lunch with a friend is job-related, don't put it on the company credit card.
The extreme opposite is the view that anything not unmistakably rong is permissible. This is called Laxism. Laxists say, "No earthly monarch with any sense of justice expects you to obsrve the speed limits unless they have been plainly posted for all who will to read. Shall we suppose that God is less fair?"
Another answer is Probabilism, that you may do B if there is a reasonable case to be made out for saying that B is lawful. (The laxist, on the other hand, is supposedly content with the remotest possibility that B might be lawful.)
Still another answer is Probabiliorism. ("Probabilior" is Latin for "more probable.") Those who hold this view say that you are entitled to go for B if and only if the case for the lawfulness of B is not just reasonable, but definitely more reasonable than the contrary case.
So we have at least four positions (I am probably leaving at least one out), which are ranked as follows:
With each group regarding those below as corrupt, wallowing in sin, cynically looking for loopholes, a threat to the moral fiber of society, and certainly no true Christians. Of course each group regards those above as morbid fanatics, legalists, obsessively concerned with dotting every i and crossing every t, sanctimonious prigs, Pharisees, hypocrites, and certainly no true Christians. Almost all Jesuit theologians have been probabilists, although one Superior General, Tirso Gonzalez (1687-1705) upheld probabiliorism, thereby creating a major crisis in the order.
The Jesuits came to be associated with the notion of "equivocation." The concept is perhaps best explained by an example. There is a story (which I have no reason to suppose is true) told about Athanasius, the great champion of the full deity of Christ, who was bishop of Alexandria in Egypt in the 300's, and was five times banished by emperors who were opposed to the orthodox Christian view. On one occasion, it is said, Athanasius was in a boat, fleeing up the Nile from the Imperial police, who were in a barge close behind. As night fell, Athanasius ordered the boatman to turn around and paddle downstream. As they passed the police barge, the leader called out, "Ahoy, have you seen Athanasius?" Athanasius called back, "You are now not far from him!" and continued downstream while the barge continued upstream. This is "equivocation." An equivocal utterance is one that has two or more meanings, while a univocal utterance is one that has only one meaning. Now it is said that a lie is ordinarily wrong in two ways: it is a sin against truth and a sin against charity. But if you are asked a question by someone who ought not to have the information (say a Nazi officer looking for concealed Jews), then it is no offense against charity to leave him with the wrong impression, and if what you say to him is technically not a falsehood (say by being equivocal), then it is not an offense against truth either, and so is not wrong at all. Jesuit moral theologians developed this notion at length, and this fact contributed greatly to their reputation as slippery customers. One Roman Catholic lecturer (not a Jesuit) that I know of (Ronald Knox) comments (approximately):
Actually, you don't find much equivocation among Catholics. It Takes so confoundedly much ingenuity at short notice under pressure, that for most people it is a purely theoretical option. In practice, faced with a situation where telling the truth would clearly be disastrous, devout Catholics behave exactly like devout Protestants--they lie!