One of the Vatican's main concerns is control of what the clergy and religious (ie, nuns and lay brothers) say and do. Every priest has to take an oath to give both "external assent" and "internal assent" to Vatican teachings. "External assent" means that the priest will teach what he is told to teach; "internal assent" means that he will believe it. Thinking for oneself is distinctly not encouraged.

There is more than just being control freaks here -- although that is a very large part of it. The official line in Catholic thought is that truth is objective and "error has no rights". There is a corollary which presupposes that what the Vatican teaches is by definition "true" (for the Vatican cannot teach falsely), and those who teach that which is not approved by the Vatican are teaching falsely and should be corrected.

Sustaining that attitude requires both ignorance of history and outright deception. After all, if the Church teaches absolute truth, how can the teachings change? Even a cursory examination of the history of doctrine shows that the teachings do change. For example, as late as Pope Benedict XIV's encyclical of 1745, Vix Pervenit, taught that the taking of interest on loans was usury and therefore sinful. The teaching has never been rescinded, but has been quietly dropped.

When I was in graduate school, I wrote a paper on how the Church went from the Council of Trent's "Biblical translations must be based on the Latin Vulgate" to Vatican II's "Biblical teachings must be based on the original languages" without ever contradicting (indeed, quoting from) the previous position papers.

Unfortunately, the quoting from previous position papers is obviously highly selective. Cherry picking quotes is really dishonest. I'm sure that when Pope Benedict was a theology professor, he would have slapped down any student who ignored evidence which did not support his thesis. (If you read Thomas Aquinas' Summa Theologia, he starts each article by citing evidence against his thesis; he then answers each one.) However, ignoring contrary evidence is expected in Vatican position papers. The most egregious recent case I can think of was Pope Paul VI's encyclical defending priestly celibacy, Sacerdotalis Caelibatus, which wholly ignores 1 Corinthians 9:5, in which Paul is saying that he has a right to be married. That he chose not to exercise that right is immaterial.

Unfortunately, this sort of thing is, as I said, expected in Vatican position papers. The paper on why women cannot be ordained, Inter Insigniores, is a piece of crap which:

• Admits that one of the main reasons for denying ordination to women has been the attitude that women were inferior to men (see, for example, Aquinas' Summa Theologia, Supplement, question 39 article 1) and says that this argument should be abandoned but then resurrects it without saying it is doing so.

• Relies on the extremely dubious argument that Christ ordained only men to the priesthood. First, even if you grant this argument, one can just as reasonably say that since Christ ordained only Jews to the priesthood, gentiles should not be priests. But the fact is that Christ did not "ordain" anyone. And since the Last Supper was a Passover Seder, and the Seder is a celebration for the family ("You shall tell your children on that day..." -- Exodus 13:8), there were undoubtedly women present.

• Makes the really silly argument that since the priest is supposed to "mirror Christ", the laity would not be able to see Christ in a woman. I daresay that the laity would be far less likely to see Christ in a pedophile. This argument also shows the Vatican's basic contempt for the laity.

Finally, Pope John Paul II attempted to quell discussion in his Ordinatio Sacerdotalis -- "On Priestly Ordination", which can be summed up as "Women cannot be ordained because I say so. Now sit down and shut up!" This argument may work with very small children (but don't count on it), but it only convinces those who believe that every burp which issues from a papal throat is the word of God. They shouldn't expect any adults to buy it.

And that is the problem with much of Vatican teachings: Cherry-picked evidence, contrary evidence ignored, sloppy reasoning, dubious (at best) history, and shutting down discussion by fiat. Now the Vatican is attempting to shut up nuns because their priorities are not the ones the Vatican wants them to promote.