It passed almost unnoticed, but last month Benedict XVI significantly upped the ante in an argument he’s made one of his pontificate’s centerpieces. To the horror, one suspects, of some professional interfaith dialoguers and wishful-thinkers more generally, the pope indicated the Church should recognize that some types of religion are in fact “sick and distorted.”

This message isn’t likely to be well-received among those who think religious pluralism is somehow an end in itself. Their discomfort, however, doesn’t lessen the force of Benedict’s point.

The context of Benedict’s remarks was the 50th anniversary of Vatican II’s opening. In an article published in the Holy See’s semi-official newspaper, L’Osservatore Romano, Benedict reflected upon his own memories of the Council. Characteristically, however, he used the occasion to make subtle but pointed observations about particular challenges presently confronting the Church and orthodox Christianity more generally: difficulties that no amount of interfaith happy-talk and ecumenical handholding will make go away.

One of Vatican II’s achievements, the pope argued, was the Declaration Nostra Aetate, which addressed the Church’s relationship with non-Christian religions. This document focused on the most theologically-important relationship—Judaism and Christianity—but also ventured remarks about Islam, Hinduism and Buddhism. Without watering down Christianity’s truth-claims, Benedict wrote, Nostra Aetate outlined how Catholics could engage in “respectful dialogue and collaboration with other religions.”

Then, however, Benedict made his move. With the passage of time, he noted, “a weakness” of Nostra Aetate has become apparent: “it speaks of religion solely in a positive way and it disregards the sick and distorted forms of religion.”

Plainly Benedict wasn’t referring to the choice of Christians to sin. The Catholic who, for instance, intentionally chooses to kill innocent life is, after all, acting contrary to the Church’s teaching. Instead Benedict appears to have in mind religions which seemingly legitimize gross violations of human dignity or inhibit its members from condemning their co-religionists’ actions.

One example is the pre-Christian pagan religions. Their view of the gods as mere hedonists who treated humans as toys, their deification of the state, their profound contempt for human life, and their conception of women as virtual sub-humans made such religions, from a Jewish and Christian standpoint, irredeemable. Then there are particular practices that indicate profound dysfunctionality in a religion’s core beliefs, such as the Aztec ritual of human sacrifice.

Which brings us to the burning interreligious question of our time. And it is this. Those people who drive trucks filled with explosives into Catholic churches in Nigeria; who torture and murder Orthodox priests in Syria and detonate bombs at their funeral; who decapitate teenage Indonesian Christian schoolgirls; who shoot teenage Pakistani girls in the head for suggesting that women should be educated; who regularly describe Jews as “pigs and apes”; or who are pursuing what Russian Orthodox Metropolitan Hilarion Alfeyev of Volokolamsk recently described as an effort to exterminate the Christian presence in the Middle-East—are they acting in ways that reflect distortions of Islam, or are their choices consistent with Islam’s central beliefs?

The jury, I’m afraid, remains out—way, way, way out—on this one. Certainly there is the Qur’anic passage: “Let there be no compulsion on religion” (2:256). But this concerns allowing non-Muslims to convert freely to Islam. It was never traditionally understood as applicable to Muslims wanting to embrace another faith. Nor is it presently inhibiting some Muslims from engaging in forced conversions or slaughtering former Muslims who have chosen different paths.

Then there are the numerous verses from the Qu’ran and Hadith that seemingly justify violence against pagans, non-believers, and “polytheists” (which includes Trinitarian Christians). Their meaning has been debated by some Muslims for centuries. Alas, Islam doesn’t possess an equivalent of Catholicism’s magisterial teaching authority that can definitely resolve disputed questions in ways that binds all Catholics.

What isn’t, however, in question is the invocation of such passages by contemporary jihadists to justify violence. Nor is this a new phenomenon. As the French historian Sylvain Gouguenheim pointed out in his Aristote au Mont Saint-Michel (2008), even as apparently an enlightened twelfth-century Muslim thinker as Averroes didn’t hesitate to preach jihad against Christians in what was (contrary to popular mythology) a not-so-tolerant Islamic Spain.

That’s not to suggest Christianity has always remained distortion-free. In our own time, we can recall those now largely-defunct liberation theologies that sought an absurd synthesis between Christianity and Marxism and, in some instances, tried to rationalize leftist violence.

One problem that took centuries to overcome was Christians’ entanglement with state power as secular rulers tried to reduce the Church to a mere government department. In many instances, this helped facilitate cruelty by Christians against Christians and non-Christians alike. Catholicism, Benedict notes in his article, was eventually able to escape this trap precisely because Christianity itself “had come into being claiming that the State could neither decide on the truth nor prescribe any kind of worship.”

But having diagnosed the sickness, Benedict didn’t shy away from outlining how the Church should tackle it. His Osservatore Romano article devoted considerable attention to another Council declaration which, like Nostra Aetate, Benedict described as having assumed even greater importance after Vatican II: the text on religious liberty, Dignitatis humanae.

So how does Dignitatis humanae help address distorted religiosity? First, Dignitatis humanae affirms as a matter of natural law that religious liberty properly understood is a fundamental human right and precondition for human flourishing. Hence it is unreasonable for anyone—Christian, secularist, or Muslim—to harass or coerce those who don’t share their religious faith or want to change their religion.

Benedict has been hammering away at this message since his 2006 Regensburg address. Yet while it’s obviously relevant for countries like Communist China, the most systematic and ferocious violations of religious liberty today are occurring in the Islamic world. To grasp just how awful things are, everyone should read Rupert Shortt’s just-published Christianophobia.

Unfortunately the problem goes beyond jihadists. As the president of the Pontifical Council for Interreligious Dialogue, Cardinal Jean-Louis Tauran observed in a recent interview: “the great problem lies in the fact that in countries where Muslim law is that of the majority, as of now no Muslim accepts that the freedom to change religion, or to choose it, should be inscribed in a legal text.” Somewhat ominously, Tauran then commented: “In all of my conversations with Muslims, many of them well-disposed, this has been a taboo subject.”

There is, however, a second dimension of Dignitatis humanae which Benedict considers critical for addressing sick religiosity. Here we should recall that the Declaration’s argument for religious liberty is not based upon the type of pluralism-for-the-sake-of-diversity babble that’s corrupted most universities. Instead it is grounded upon religious liberty as a precondition for the honest search for and embrace of religious truth.

Just as the Church sees the truth about man as the foundation for religious liberty, Catholicism also regards truth as the end of religious liberty. Dignitatis Humanae was never about putting error and truth on the same footing. In fact, it explicitly disavowed that claim. For why else would you rationally choose to be a Catholic unless you’re convinced that orthodox Christianity’s claims are true and all other religions are therefore either incomplete to varying degrees or deeply erroneous? To that extent, Dignitatis Humanae was always concerned with creating the conditions for the Church to propose the truth of Christianity in a context in which everyone was free to argue about the truth without killing each other.

As Benedict wrote in his Osservatore Romano piece, “the Christian faith, from the outset, adopted a critical stance towards religion, both internally and externally.” If, as reported, Benedict is preparing an encyclical on faith to complete what would be a trilogy of encyclicals on love and hope, he may well use the occasion to illustrate how faith can become positively pathological, just as he’s shown how love can be distorted into liberal sentimentalism, and hope into secularist utopianism.

And as every single Christian living in the Middle East today knows, that’s a warning about faith which today’s world desperately needs to hear.