Wednesday, May 26, 2010

Boccaccio's argument for the Catholic faith

In the second story of the first day of the Decameron, we have the story of how Giannotto tried to convince a Jewish friend named Abraham to become a Christian. Giannotto is a fairly ignorant merchant, but his arguments have sincerity. Abraham, on the other hand, is a theologically well-educated Jew. But instead of making mincemeat of his friend's arguments, out of friendship and perhaps a movement by the Holy Spirit (so the narrator suggests), he resolves he'll go to Rome to see what the alleged vicar of Christ is like, in order to decide which faith is correct. Giannotto thinks all is lost:

if he goes to the court of Rome and sees the wicked and filthy lives of the clergy, not only will he not change from a Jew to a Christian, but if if he had already become a Christian before, he would, no doubt, return to being a Jew.
Nonetheless, he sends his friend with his blessing. Abraham goes to Rome and sees all the sin among "the Pope, the cardinals, and the other prelates and courtiers". Abraham returns, and Giannotto is sure that there is no longer a chance of conversion. He asks Abraham what he thought of the Papal court. Abraham responds:
I don't like them a bit, and may God condemn them all; and I tell you think because as far as I was able to determine, I saw there no holiness, no devotion, no good work or exemplary life, or anything else among the clergy; instead, lust, avarice, gluttony, fraud, envy, pride, and the like and even worse (if worse than this is possible) were so completely in charge there that I believe that city is more of a forge for the Devil's work than for God's: in my opinion, that Shepherd of yours and, as a result, all of the others as well are trying as quickly as possible and with all the talent and skill they have to reduce the Christian religion to nothing and to drive it from the face of the earth when they really should act as its support and foundation. And since I have observed that in spite of all this, they do not succeed but, on the contrary, that your religion continuously grows and becomes brighter and more illustrious, I am justly of the opinion that it has the Holy Spirit as its foundation and support, and that it is truer and holier than any other religion.... So, let us go to church, and there, according to the custom of your holy faith, I shall be baptised.[note 1]

Now, while over the past century we've been blessed by popes of exemplary holiness (though of course there has been much wickedness elsewhere among the clergy and laity), the argument does not require present papal wickedness. What it requires is the surprising way that despite all the wickedness, the Church survives and grows. One might object: but if the Catholic faith were the true faith, wouldn't we expect that the hierarchy would be holy in the first place? While the analogy is not perfect, this is similar to asking, in the case of someone who was apparently miraculously healed, why God would have permitted the illness in the first place. The question is a good and tough one, but it does not make the healing (in the case of the cancer) or the survival and growth (in the case of the Church) less wonderful.

We might enhance the above by recalling another argument. The Catholic Church's formal teaching is coherent, despite having been developed over twenty centuries. The teachings are not only coherent at one time, but are coherent over time (and cohere with Scripture as well, but I don't want to rely on this if the argument is to be convincing to Protestants). The best explanation of this coherence is that it is the work of the Holy Spirit. Arguments along these lines have been developed by Menssen and Sullivan. Observe, too, how this consistency is not observed in most other Christian bodies—sexual ethics is a nice example, with contraception once condemned by all theologians (including Luther and Calvin) and now widely accepted by non-Catholic bodies (with the notable exception of some individual Protestants and some Orthodox bodies—though even in the latter, there is a reluctant acceptance of remarriage after divorce). But now combine this argument with Boccaccio's. The consistency over time is amazing enough—but when one notes that the consistency includes popes who were, apparently, quite wicked, but who, nonetheless, did not formally teach the Church anything contrary to the earlier faith, the argument becomes even stronger.

22 comments:

Heath White said...

Regardless of its logical strengths, I am pretty sure this will never become a *popular* argument for the truth of Catholicism. :-)

Alexander R Pruss said...

But it might make a nice opening salvo in a public debate with an anti-Catholic interlocutor whom one knew ahead of time (from his past practices) to be armed with a litany of evils done by Catholic clergy. You start off by giving even worse evils than the anti-Catholic could find, then you give Boccaccio's argument, and he has to redo his presentation. :-)

D. A. Armstrong said...

I think I'm going to have do some more thinking and work on this argument. This is one of those one of a kind arguments that could have many illustrious applications. Could you imagine using this argument against someone like Dawkins? I think the results could be astonishing.

Jarrett Cooper said...

The obvious problem as you hinted at, Protestants will be quick to disagree with your assertion that Catholic teaching coheres with Scripture. I think it would be importatnt to show that not only does Catholic teaching cohere over time with itself, but that the teaching over time has always cohered with Scripture as well. If this is to be an argument for Catholicism, it would be important to show that. If not than any Christian could be able to use this type of argument.

Other than that, the argument about the working of the Holy Spirit keeping the Church alive and growing can be viable. Though there could a whole array of objections physiologists and anthropologists might come up with, as to why the Church still exists as it does. This could then complicate things quite a bit.

Dan Johnson said...

Alex, until you get to the "coherence" part at the end, I don't see how this argument is an argument for Catholicism in particular rather than for Christianity in general. In fact, I would think that since one of the distinctive claims of Catholicism is some kind of divine guidance for the visible organization and hierarchy of the Church, the flourishing of Christianity despite the corruption of the hierarchy actually constitutes an argument for the truth of a broadly Protestant understanding of Christianity and the church (in terms of the priesthood of all believers and the invisible church).

I agree that it may serve as a nice argument against unbelievers, but I don't see how it supports Catholicism over against Protestantism.

The coherence argument seems to be an entirely separate argument.

Alexander R Pruss said...

I think the consistency argument is organically related to the Boccaccio argument. Keeping the same faith is a part of the survival of the survival of the Church. And the diachronic consistency is particularly amazing--particularly calls out for explanation--because of the way it was maintained by a hierarchy that at various times was quite morally corrupt. (The Church does not teach that the Popes and Councils are going to be protected from sin. The essential difference between them and the laity is in respect of teaching authority, not personal holiness, and it is in respect of the teaching authority that they are promised to be protected.)

If one demonstrated consistency with Scripture, that would, obviously, strengthen the case. But even if one didn't do that, the internal diachronic consistency would be itself a powerful argument. Compare, for instance, the lack of diachronic consistency in non-Catholic Christian bodies. (And if a religious body moves from teaching p to teaching ~p in a matter on which Scripture is not silent, then one of the teachings is incompatible with Scripture.) We would expect diachronic consistency from a Church that is, in St Paul's words in 1 Timothy, a "pillar and bulwark of truth". But only the Catholic Church (and to a lesser degree the Eastern Orthodox Church) can reasonably claim such consistency.

Moreover, we can run an inductive argument: there is consistency between the 20th and the 19th century, between the 19th and 18th, ..., between the 3rd and the 2nd. Therefore, probably, there is consistency between the 2nd and the 1st, and hence between the 2nd and Scripture, as Scripture belongs to the 1st.

It's an interesting question what it would it take to establish "consistency with Scripture". It would be a project beyond our power, I suspect, to show that there is a plausible interpretation of all of Scripture that is internally consistent, consistent with our best philological data, and consistent with every Catholic teaching. No Christian body has done that for their teaching.

But for the purposes of a plausible argument, one might opt for something more modest: Show that for every text of Scripture and Catholic teaching alleged by serious theologians to be in contradiction there is an interpretation of the text of Scripture that is not very implausible to us and that coheres with the teaching.

One might think "not very implausible to us" is too weak a standard. However, it is plausible that for some texts of Scripture the correct interpretation is one that we would assign a fairly low probability to. For instance, no doubt there is some text T that has four leading mutually incompatible interpretations, each of which interpretations has arguments for and against it such that an impartial observer will have to say that each of the four interpretations is just as likely. In that case, if the correct interpretation is one of the four, it's an interpretation that we'd assign only a probability of 1/4 to. So the correct interpretation might be an improbable one.

Joe said...

Alex,

A question about your coherence argument… You say that “Catholic Church's formal teaching is [diachronically] coherent,” and this claim seems plausible at least where what you call “formal teaching” is restricted to things widely thought of as doctrine. (Popes, as far as I know, have never begun to widely assert the denial of something previously proclaimed in super serious tone by an ecumenical council, for instance.) But I’ve always been under the impression that there has been a fair amount of variation over time in what the hierarchy has taught about other matters, particularly about moral and political issues. (The permissibility of charging interest on loans and the acceptability of democratic political arrangements are probably examples, and pacificism may be as well.)

In fact, as I understand it, one common criterion used in the process of figuring out whether a particular claim is doctrine would be some kind of test in terms of whether the claim has been universally and stably taught by the hierarchy. If this is a legitimate criterion, and what you have called “formal teaching” includes only doctrine, then the impressiveness of Catholic formal teaching’s coherence is diminished, perhaps significantly. This is because, on matters where there has been a diversity of teaching (without definitive direction from an infallible organ of the Church), all claims will be ruled out from consideration as part of the body of formal teaching, virtually by stipulation. The substance of the coherence will then just boil down to the fact that super-serious conciliar pronouncements (and presumably ex cathedra papal pronouncements) haven’t been contradicted by the hierarchy and there has been consistency across time on some other teachings. But how impressive is the list of these other teachings? I’m interested in your thoughts on this. (I should also offer the disclaimer that I’m a total novice at church history and would welcome being corrected on any empirical errors.)

Alexander R Pruss said...

1. I think it's a good thing that there be degrees of teaching authority--that there be a possibility for a pastor, bishop or pope to teach something without that having the full authority of the Church behind it.

2. I don't actually believe that there were very few infallible papal teachings. I think the Vatican I definition has probably been fulfilled a number of times. But even if there were only a few, that too is interesting given the various "convenient" teachings bad popes could have promulgated.

3. In addition to infallible papal teachings, there is the infallible teaching of the "ordinary magisterium", when at some time all the bishops around the world, without a council but in an ordinary way, are definitively teaching something. That's the sort of infallibility the case of contraception has.

4. We limit the Church's infallibility to "matters of faith or morals"--those are the subjects on which Jesus Christ left us his teaching. This does include moral matters, but some care needs to be taken to separate out moral components from empirical ones. Thus, if the Church had taught that it's wrong to deprive innocent people of air, that teaching would have been combined from two claims: (a) it's wrong to kill the innocent and (b) depriving people of air kills them. The Church's primary authority would apply only to (a). Claim (b) is an empirical claim, and if future medicine found a way of depriving people of air without killing them, that would be fine.

5. So, yes, there are complexities behind the argument. However, it is worth noting that even with similar kinds of provisos, such claims cannot at all plausibly be made except by the Catholic and Orthodox Churches.

Alexander R Pruss said...

6. The case of interest on loans is difficult. I first note that there does not seem to be a formal teaching, of pope, council or ordinary magisterium, that interest on loans is acceptable. Granted, the practice of the bishops has been to accept interest-taking, but the moral practice of the members of the Church is not guaranteed to be perfect--that's central to Boccaccio's argument. So one possible answer is: "Yes, the Church once taught that it's wrong to take interest on loans. The present practice by clergy of putting Church funds in banks is, thus, immoral." This move is always available as a retreat. Nor is it at all trivializing or liberal. It's just a matter of fact that there hasn't been, to my knowledge, any formal teaching that it's permissible to charge interest on loans (especially, non-productive loans--investments are perhaps a different matter).

In fact, I do not think this answer is the right one. The one I prefer is more subtle, and you might think it's too foxy to be right, and if so, then I can retreat to the previous answer. The foxy answer is that the meaning of a financial policy, and of money itself, depends on the economic system in place. Money is not essentially a physical object (if everybody had great memories, no physical tokens outside the memory would be needed). Rather, money is a social institution, defined by the rules in play governing its use.

Moreover, money is not a natural social institution in the same sense that marriage is. Marriage is natural in the sense that the absence of the institution of marriage from a community is in constitutive of a failure of the community's flourishing. However, while it may be empirically true that communities without the institution of money don't fully flourish, the lack of the institution of money (or more generally of private property) does not itself constitute a failure of community flourishing. This isn't just my view--I am pretty sure Thomas Aquinas would say this, given what he says about private property being our (quite sensible) invention.

If this is right, then monetary and property institutions can legitimately differ between communities. (Of course, there no doubt are bounds on the legitimate degree of variation.) And so words like "money" and "property" denote different, though related, institutions in different communities. If this is true, then the teaching on interest might be well be relative to a social system. It could even more strongly be the case that the very words "money", "property", "loan", "interest" (or their "equivalents" in Latin and Greek and other languages) mean different things. If so, then we can say that the teaching of the medieval church on "interest on loans" (in their sense of these words) is quite correct. But even if we don't go so far as to suppose different meanings of words, we might not unreasonably say that the teaching is relative to the particular economic social practices.

Of course, the danger with this is that it might lead to a trivialization of the claim that the Church's teaching doesn't contradict itself. Can't we do the same with any moral teaching? I think not. For while the Church has been friendly to the view that the institution of property is not a matter of natural law, but a matter of mere (reasonable) social construction, the Tradition holds, I think, that such things as marriage, human life or the Sacraments are not merely socially constructed.

Alexander R Pruss said...

7. A less radical move would be to say that what the Church has always condemned is the practice of excessive interest. But what is in fact excessive may differ from social system to social system. Perhaps in the medieval system, any interest greater than zero is excessive. In our day, I don't know what interest is excessive, but the penalties and punitive interest charged by many (all?) credit card companies have surely crossed the line into the sin of usury.

Joe said...

Thanks for the response, Alex. To address your points:

1. Agreed. There are certainly advantages to this.

2. I wonder actually about how many realistic temptations there would have been for bad popes to promulgate “convenient” teachings with ex cathedra pretensions. I don’t know much about what papal pronouncements might qualify for ex cathedra status (aside from the standard Immaculate Conception and Assumption pronouncements). I worry, though, that there would have been strong cultural and political pressures to keep any such pronouncements within the theological realm. But if there were pressures like this, then the expediency of making pronouncements would be lessened, since there wouldn’t be much tangible benefit to the greedy (or lustful, or temporal power seeking) agendas of bad popes in making them. Even if there weren’t these pressures, though, and popes felt free to make moral pronouncements, I wonder how much temptation there would have been. If a pope’s agenda involves rapacious greed (e.g.), would there really be any benefit in calling attention to that greed by trying to convince people it was sanctioned by God with a supposedly ex cathedra pronouncement? (I’m obviously just speculating here, though. I don’t really know. And I suppose there is room for more subtle Machiavellian machinations by evil popes. Perhaps they could condemn the preferred positions of their political opponents to gain some kind of edge, although in practice I wonder if their opponents had any more at stake in moral and theological debates than they did.)

A harder test might not be so much the stereotypically corrupt popes, but rather the morally/ theologically speculative and intellectually overconfident popes. I don’t know enough about Church history to know if any popes fit this bill, but it would be interesting if there are some who were clearly privately heretical and appeared ready to try to impose their private heresies on the Church, but then didn’t.

Joe said...

3. Fair enough. I’ve never been entirely clear on what would qualify a claim as being definitively taught by the world’s bishops (as opposed to being just a popular view among bishops at a particular time). Clearly, if there’s an accepted plausible way of drawing this distinction (or at least one that can be articulated) that doesn’t trivialize the consistency claim (by, e.g., making a criterion for a claim counting as a teaching of the ordinary magisterium that the claim not have been contradicted by earlier claims made by popes or signfiicant numbers of bishops), then this would make the argument stronger than I had anticipated (at least assuming that none of these teachings do contradict earlier or later teachings).

4. I agree.

5. I agree. I was focusing more on the argument as part of a case against the opponent of Christianity, rather than against the Protestant.

6 and 7. As for your fallback solution, I agree that the bullet you are talking about biting isn’t horrible. I wonder, though, if the Eastern Orthodox couldn’t use this kind of move to explain away an apparent inconsistency in their teaching—namely, the one about allowing remarriage after divorce. I don’t know if the Eastern Orthodox have tried to propound teachings to the effect that this sort of practice is OK, or rather just engaged in the practice of remarrying people after divorce. If the latter, then a defender of Eastern Orthodoxy could claim that this represents a practical abuse, rather than an inconsistency in teaching. (Though perhaps you would insist that a widespread practical abuse in the marriage realm is very different than one in the financial realm, perhaps for reasons in the same spirit as the motivation behind your natural/conventional distinction. And of course your argument is not primarily intended as an argument against Eastern Orthodoxy anyway.)

It would be nice to be able to relativize the usury teachings to some kind of medieval (or at least pre-modern) social/economic framework. I’m a little skeptical, though. The hierarchy seems to have condemned charging interest of any kind as usury (and therefore impermissible) until well into the 19th century, and it strikes me as strained to think of 19th century financial conditions as relevantly different from current ones.

(General) I’m still worried a bit about the political teachings, although I fully admit to not being well-versed enough in the historical material to make a solidly informed judgment. I was always under the impression that the hierarchy was pretty zealous in condemning democratic political arrangements prior to at least the middle of the 19th century (and maybe later), and didn’t attempt to temper or qualify their claims as just pious opinions or minimally guided teachings.

Alexander R Pruss said...

A. Maybe the Orthodox could say that the marriage practice is wrong, but not taught. But insofar as their practice is embodied in liturgy, that's pretty serious, especially since according to their own theology, liturgy is one of the primary modes of the Church's teaching.

B. A quick look at a standard reference work shows that by the 1830s, there was tacit permission for interest-bearing business loans, and it must have gone on for some time before that. I really don't know much about the history and theory of financial systems. It is compatible with the relativity story that the empirical fact that the situation has changed had not yet been noticed--the moral content of the teaching is still correct, but the empirical claims in it (such as that presently there is "money" and "interest" in the relevant sense of the word) might be mistaken. One way of running this line would be to say that the Church's vocabulary is often "old-fashioned"; in 1795, say, she might have used "money" (or the Latin equivalents) in the 1395 sense of the word, rather than in the 1795 sense of the word.

C. The political teachings one would have to look at the details of. I suspect a number of them are prudential rather than doctrinal. In regard to democracy, I found it surprising just how central the people are to Aquinas' political philosophy. A crucial question in political philosophy is the problem of what defines the rules by which laws get promulgated. If Congress passes a bill and it is signed by the President, it is to be obeyed. If my best friends pass a bill, and I sign it, nobody needs to obey (except maybe my children). What's the difference? If one says "The Constitution says that Congress and the President get to make laws", that just pushes the problem back one step. After all, my friends could write a "Constitution", too. Aquinas' solution is that there are two kinds of human law: custom and explicit law. The idea, I understand, is that the custom of the community answers questions like who gets to make the laws, etc. So, custom is the more fundamental kind of law. And custom is defined by the practices of the people. (It can't just be the custom of the nobility, say. For then it wouldn't answer the question of who counts as the nobility.) So in Aquinas' political thought, there is a fundamental democratic element. The people don't necessarily elect those who govern them, but the people's practice defines the fundamental constitution. (This neatly solves such problems as what is to be done about countries whose regimes and constitutional orders were changed in illegimate ways--which may in fact be a majority of countries. When custom accepts the new order, the new order becomes the legal order--of course, within the limits of reason and morality.) But I really know next to nothing about this stuff. I just heard someone who knew about it talk about it once, and I may be misremembering a lot of it.

Joe said...

A. Yeah, I agree there’s some serious explaining that has to be done by the Orthodox if this reply is to be plausible.

B. I’d be interested to know more about the history of Church pronouncements on this topic, and about the hierarchy’s understanding of what the economic circumstances were like around them at various times. It wouldn’t shock me if the empirical presuppositions of the teachings were outdated, as you suggest.

C. I’d never heard that about Aquinas. I’m assuming he would not be heterodox on a point like this, so that’s encouraging. I’ll look into the details of the history more.

Alexander R Pruss said...

A. It is my understanding that many of the Orthodox subscribe to a moral doctrine of oeconomia, according to which ecclesiastical authority can make exemptions from the moral law (e.g., the prohibition on remarriage after divorce) when doing so is for the good of the individual's soul. This is a pernicious consequentialism. I do not know how deeply embedded this is in Orthodox doctrine. So there is, alas, a theory behind the permission of remarriage.

B. This article seems helpful. Particularly interesting is the quote from the Fifth Lateran Council in 1515: "For that is the real meaning of usury: when, from its use, a thing which produces nothing is applied to the acquiring of gain and profit without any work, any expense or any risk."

In our present economic system, money is not a thing that produces nothing. Nor is it the case that lenders undergo no risk. On the contrary, as the mortgage crisis showed, they undergo considerable risk.

C. I am getting this from my memories of what Mark Murphy said at the first of the Princeton Summer Thomistic Seminars. If you email me, I can ask him for references. Or you can just email him (get his email address from the Georgetown Phil Dept directory) and tell him I sent you his way. I hope I didn't garble it too much.

Jarrett Cooper said...

Professor Pruss,

I'm wondering what's your take on the CCC 2485, where in the 1997 edition some words were taken out. The earlier (1994) edition stated that to lie is “to speak or act against the truth in order to lead into error someone who has a right to know the truth .”

Then in 1997, the revised edition eliminates the words “who has a right to know the truth."

I was curious if you think this hurts the internal diachronic consistency you mentioned?

I agree with Edward Feser (and I'm sure many others) that it's a good thing the Catholic Church took out the "someone who has a right to know the truth." To me that's very vague. How do we determine who has the right to know the truth? That's asking for heated debates in trying to find an answer to that.

Alexander R Pruss said...

Well, the simple answer is that the first version of the text was based on an unfinalized version of the Catechism. As I recall at the time, there was a lot of excitement over the new Catechism, and a desire to get it in people's hands quickly, and as a result a draft was published, with the expectation that it would be revised later. Since it was a draft, it has very real authority. Most of the revisions for the final version were extremely minor, but this one is an exception.

You might also want to see this quote from Cardinal Ratzinger on the authority of the Catechism in general.

In an appendix to the Apologia, Cardinal Newman gives a survey of the Church Fathers' views on lying, and they are uniformly condemnatory of lying.

There has, I think, been an interesting shift in attitudes to lying among non-Catholics (and, alas, some Catholics, but fortunately not the magisterium). I don't know that I've met any non-Catholics who think it's wrong to lie to save a life. Yet, during the time of the prosecution of Catholics in England, one of the big accusations against Catholics was precisely that they would lie to save their skins. The kernel of truth in the accusation was that many of the Catholics subscribed to a theory--which is not Church teaching, but accepted by a number of theologians, with the notable exception of Cardinal Newman--on which it was permissible to say things that were misleading but which could (or should?) be strictly and carefully interpreted to come out true.

Jarrett Cooper said...

Definitely, if that is the case (the 1994 edition not being official) then that would certainly clear up the problem.

However, if that is not so then I think it's problematic. Though all of this could possibly arise from my unproper understanding of the Catechism. I don't find teaching that is expounded upon or is further explained worrisome (in fact, I would find it beneficial and expected), but I would find teaching that is eliminated or taken back to be bothersome.

Granted, the most immersion I have with Catholicism comes from the high school I graduated from (Mount de Sales Academy). Other than that it's your blog, Edward Feser's blog, and First Things Blog (with not all of the posters being Catholic). I've been contemplating this post and have a wish list of some books I want for Christmas to reflect upon!

Alexander R Pruss said...

Have a look at the wikipedia article on the Catechism. The official version came out in 1997 in Latin. The 1994 edition was based on a "provisional" French text.

Jarrett Cooper said...

Mr. Pruss, thanks.

It's now clear to me. I was confused -- I naturally wanted to think that both the 1st edition along with "2nd edition" were official, but only the 2nd edition is.

Jarrett Cooper said...

Prof. Pruss,

Have you heard about the Pope's comments (in a interview) about condoms and its use being justifiable -- in certain cases.

However, one article I read [A CNN article] quoted a guy that noted the Pope's comments is not "official Vatican policy." Then the AP press has a paragraph that reads, "William Portier, a Catholic theologian at the University of Dayton, a Marianist school in Ohio, said he had not read the report in the Vatican newspaper, but he said it would be wrong to conclude that the comments mean the pope has made a fundamental, broad change in church teaching on artificial contraception."

"He's not going to do that in an offhand remark to a journalist in an interview," Portier said.

So, clearly it's not official Church teaching. Just thought it was interesting to note, given your post and the conservation following it.

Alexander R Pruss said...

The remark seems to be that it can be a step in the right direction for a prostitute to use condoms. On my view of Catholic sexual ethics, that is right. Without condoms, the prostitute is sinning against both chastity and health, while with condoms, the prostitute is sinning "only" against chastity. It's not so much that the use of condoms is right--and the Pope doesn't say it is--as that prostitution-without-condom is a greater sin than prostitution-with-condom.

That said, there is an important issue below the surface here. There are three different families of Catholic arguments against contraception, which have different consequences in cases like this.

Type 1: Classic natural law arguments. These arguments condemn the use of contraception as a perversion ofreproductive faculties.

Type 2: The use of contraception involves an anti-life intention. Finnis, Grisez and Boyle are the famous defenders of this argument.

Type 3: The use of contraception is contrary to the nature of marital union. John Paul II is the most famous defender of this argument.

These arguments all agree on the core point that contraception within marriage is wrong. But they have differing consequences in non-marital cases. Non-marital cases are cases of sin anyway, but the question is whether contraception adds another sin to mix.

Type 1 arguments seem to apply outside of marriage just as well as within marriage. Those arguments imply that the use of contraception in fornication and prostitution adds perversity to the unchastity. At the same time, it lessens the imprudence. So it makes one dimension of the sin worse and another dimension less. On this view, one cannot say that the use of condoms is permitted in non-marital contexts.

Type 2 arguments seem to allow the use of Double Effect in cases where condoms are used not for contraceptive purposes but for the prevention of disease. The failure to reproduce is not intended. What is intended is the prevention of disease, and the failure to reproduce is an unintended side-effect. This is why some Catholic theologians think that it is OK for a married couple where one party is HIV+ to use condoms to prevent disease-transmission. The condoms aren't contraceptives in such a case.

I think that Type 3 arguments imply that the use of condoms within marriage is wrong even when the condoms are used for disease-prevention, because the condoms are still--quite literally and physically--opposed to the union of the couple. However, Type 3 arguments do not say much about the use of condoms and contraception outside of marriage. One could even make a case that (a) sexual union should not occur outside of marriage; (b) condoms decrease the degree of sexual union; and so (c) fornication-with-condoms is a somewhat lesser sin than fornication-without-condoms (though both are mortal sins, still). It could, however, be that the anti-unitive aspect of condoms wounds erotic love in committed (still sinful, of course) non-marital relationships, but that won't be an issue of with prostitution. So, Type 3 arguments will not prohibit the use of condoms, or of contraception, in cases of prostitution.

So, what the Pope says is fully in line with two out of three major approaches to the wrongness of contraception. The Church does not teach which of these lines of argument (if any) is the right one. It could be that more than one line of argument is successful.

And even Type 1 arguments can perhaps be reconciled with the letter of the Pope's remarks. He doesn't say that the use of condoms is right in such cases, but that it can be a first step in moral progress. Compare this case. Frank has a history of coming up to random people, beating them senseless with a stick and then taking their money. Recently, he has taken to going up to people, brandishing his stick, and asking them to hand over the money. Do we want to say that threateningly asking for money is right? No. But in his case, it's a first step in moral progress.