This was the Vatican II document helping Catholics understand the Church’s response to other religions and this article from Crisis Magazine is an excellent analysis of it.
I have encountered serious Catholics who have invoked the Vatican II document Nostra Aetate (Declaration on the Relation of the Church with Non-Christian Religions) as seemingly discouraging or even reproving any kind of searching public examination and criticism of Islam. What exactly does this short statement of the Vatican II Fathers have to say about relation of the Church to non-Christian religions and to Islam specifically?
It says, first, to be sure, that the Church seeks to promote fellowship among all men (#1). Secondly, it speaks about how all historic religions that have grown up in the context of well-developed cultures have attempted to provide answers to the most central questions that confront man, such as who he is, what the meaning of his life is, and what kind of moral life he is to lead. Thirdly, it makes clear that there are elements of truth in all of these religious traditions, and so the Church “rejects nothing that is true and holy in” them (#2). Finally, it “exhorts” Catholics to engage in “dialogue and collaboration with the followers of other religions” so they can recognize “the good things” found among them (#2).
The document also makes clear the following. While the “precepts and teachings” of these other religions differ in many respects from the Church’s, they “often reflect a ray of that Truth which enlightens all men” (#2)—that is, they obscurely express Christ in some way. It also stresses that the dialogue and cooperation with them must be “carried out with prudence and love” (#2). In other words, while acting in charity Catholics must always bring discernment to their dealings with adherents of non-Christian religions. The Church—and by extension, the faithful—“ever must proclaim Christ ‘the way, the truth, and the life’” (#2) and “the cross of Christ as the sign of God’s all-embracing love and as the fountain from which every grace flows” (#4). What this means is that they can never back away from holding—always charitably, to be sure—that she alone teaches the fullness of the truth.
As far as Moslems are concerned, Nostra Aetate regards them “with esteem,” because as a fellow Abrahamic faith they submit to the one true God, revere Jesus as a prophet even if they don’t recognize him as God, have devotion to the Blessed Mother, and like Christianity “value the moral life and worship God especially through prayer, almsgiving and fasting,” and also await the resurrection of the body on Judgment Day (#3).
The document also affirms that Catholics cannot refuse to treat any person “in a brotherly way,” since all are created in the image of God, and that there is no basis “for any theory or practice that leads to discrimination between man and man or people and people, so far as their human dignity and the rights flowing from it are concerned” (#5).
A key point here are that Catholics cannot let themselves slip into a kind of religious syncretism when viewing other religions or in their dealings with their adherents. Charity is exhorted, but so is prudence. When the document says that dialogue and cooperation must be carried out with these things in mind, it is essentially cautioning Catholics not to slip into a mindset of moral or religious equivalency. When it says that these other religions have elements of the truth—which unwittingly, for them, reflect the truth of Christ—it is making clear that, as stated, the Church alone embraces and teaches the fullness of truth and the complete path to human salvation. She, in effect, is reminding the faithful that they cannot forget this or cease to make it a central element motivating their dialogue. Indeed, it has been just such a neglect that has abundantly characterized ecumenical relations since Vatican II and has helped retard the Church’s efforts at evangelization. Where Catholics have not succumbed to a functional religious syncretism, many have failed to understand that a charitable attitude can make it possible to stand solidly for principles and even speak the truth and still get along with people.
If anything, these points from Nostra Aetate invite, rather than discourage, a careful and honest examination and evaluation of the beliefs of non-Christian religions and a clarity in pointing out—especially to fellow Catholics, in the interest of their increased understanding—the realities about their origins, problems in their teaching, and ways in which they conflict with Catholic truth. It goes without saying that this is always supposed to be done charitably and respectfully, but getting to the point and laying out the realities is not the same thing as engaging in polemics. Many Catholics who have invoked this document to discourage blunt, even if well argued, criticisms of Islam have confused this.
Some of the things that would seem to be fair game in a careful examination of Islam are whether some of its basic teachings may encourage violence as a way to spread the faith, the historical background and character of Mohammed, whether an arbitrariness and radical voluntarism took deep root in Islam way back in the Middle Ages when it turned its back on philosophy (as Robert Reilly brilliantly discusses in The Closing of the Muslim Mind), how much Islamic teaching really permits coexistence with and equal treatment of other religions once it gains political power, whether its basic teachings give rise to the Islamic radicalism we witness today or if this is a divergence and corruption, and whether for it religious dominance also means political domination. In light of what we have witnessed historically and in the present crisis caused by Islamism, these are hardly red herrings or an unjustified sounding of alarms.
Let’s remember that the Church never asks the faithful to surrender reasonableness or good judgment in considering things. Nostra Aetate does not ask us to do that in our evaluation of Islam.