Andrew McCarthy discusses those issues at length in an October 20th essay on the NRO site. An excerpt:
Religion as cosmetic reverence shorn of substantive content is a virtue only the postmodern, post-doctrinal West could love: its self-congratulatory elites having evolved beyond anything so quaint as doctrine and arrived at . . . nihilism. Ratzinger knew better. Doctrinal differences never lose their salience because it is doctrine that defines a believer. To airbrush our differences even for the well-intentioned purpose of elevating “peace” as a transcendent value is to deny the essence of who we are.
Thus should multi-religious prayer be a rarity, Ratzinger admonished “to make clear that there is no such thing . . . as a common concept of God or belief in God.” Far from religion, religious relativism oblivious of doctrinal content, eroding real faith is a destroyer of conviction. The philosopher cardinal grasped, moreover, that the obverse is true: Real faith has such transcendent power that religious relativism this “common concept of God,” this nihilism swaddled in politically correct reverence cannot compete.
Real faith is an ultimate claim about what constitutes the good life. It is the antithesis of relativism, whether that relativism takes the form of an amorphous quest for “peace” or similarly fashionable pieties: “anti-terrorism,” “social justice,” “equality,” “freedom,” or “democracy.” Such noble ideals, we blithely assure ourselves, could not conceivably provoke dissent from any creed worthy of the name “religion.” Indeed, in our post-doctrinal West, such dissent actually deprives the underlying belief system of any standing as religion and, therefore, of any need for us to examine the belief system or come to terms with how broadly its convictions are held. That was the wayward reasoning of the British government after the jihadist bombings of July 7, 2005. Terrorism, pronounced Home Secretary Jacqui Smith, is “un-Islamic activity” simply by dint of its being terrorism. After all, Islam is a religion, so violence perforce could not possibly be rooted in Islamic doctrine. Q.E.D. why tarry over what the doctrine actually says?
Well, because it matters. There is no common concept of God, and the mush that passes for this feel-good illusion cannot obscure that real faiths exist. They are different because they represent different claims about ultimate truth. One cannot apprehend what those claims are, and how the believer is apt to act on them, without studying doctrine and respecting the divergences between faiths. Substantive differences, civilizational chasms, and supremacist ambitions do not evaporate just because we wish to believe everyone wants “peace.”
Real faith inspires. It has meaning and gives purpose to our lives. Real convictions, no matter how loathsome they may seem to an unbeliever, inspire allegiance and action. Nihilism, no matter how alluringly coifed, is a feckless competitor. Something will always beat nothing.
Read the entire essay, "Sharia and Freedom". Back in 2006, shortly after Pope Benedict XVI's address at Regensberg, Fr. Joseph Fessio, S.J., wrote the following:
Christianity and Islam make incompatible truth claims. Despite the difficulty in determining who can speak authoritatively for Christianity or for Islam, there are elements of belief common to all Christians which are incompatible with elements of belief common to all Muslims. The two most obvious and most fundamental are the Trinity and the Incarnation.
I would expect an intelligent and informed Muslim to consider me a blasphemer (because I introduce multiplicity into the one God) and an idolator (because I worship as God a man named Jesus). Should I be offended if he says so publicly? Should I not rather be offended if he conceals his position for the alleged purpose of fostering dialogue?
The question of respect is entirely distinct. Benedict is clearly aware of this distinction as evidenced in the official Vatican statement subsequent to Benedict's lecture, where the Secretary of State refers to his "respect and esteem for those who profess Islam". That is, one can and should respect Muslims (those who profess Islam) as persons with inherent dignity; but where there are incompatible truth claims, they cannot be simultaneously true. One cannot hold one as true without holding the other as false. Any religious dialogue should begin by examining the evidence for the incompatible claims.
It's worth noting, however, that while consistent Christians and Muslims in fact hold the position of the other to be erroneous in important ways, the Christian is not obliged by his faith to subject the Muslim todhimmitude nor to deny him his religious freedom. There is a serious asymmetry here, which Benedict has criticized before. The Saudis can build a multi-million dollar mosque in Rome; but Christians can be arrested in Saudi Arabia for possessing a Bible.
Certainly, it may sound provocative to make the claim the Emperor did. But why (since Christians believe that God's full and definitive revelation has come with Christ, who brings all prophecy to an end) isn't it just as provocative for a Muslim to proclaim that Mohammed is a new prophet, bringing new revelation that corrects and supplements that of Christ?
Is it really offensive to say that Christians and Muslims disagree profoundly about this? Is not this the necessary starting point that must be recognized before any religious dialogue can even begin?
His essay, "Is Dialogue with Islam Possible?", can be read at Ignatius Insight. And, in my recent editorial,"God and 9/11", I look at some closely related subjects, with special reference to both the Regensberg address and Bl. John Paul II's encyclical, Veritatis Splendor:
The West, in general, has embraced this "objective" subjectivity; we can call it "scientism", but that is just the head of the monster, for the real demon is rebellion against truth and the Author of truth. The soothing, seductive words in the Garden are words now shouted from the rooftops, rendered perfectly with special effects, and fired through cyberspace countless times each day: "And you will be like God, knowing good and evil" (Gen 3:5). This "knowing" is the act of false creation, or, better, the sacrilege of depraved re-creation (and, yes, recreation), the desire to make good into evil, and evil into good.
The flip side of this warped coin is what John Paul II calls "heteronomy". It comes from the two Greek terms for “other” (heteros) and “law” (nomos). It asserts that God is the Universal Law-Giver, but because God is omnipotent and omniscient, he cannot allow man to really, truly posses free will. The sovereign Creator’s divine law is forced upon man, the creature, who has no right or reason to complain about such an arrangement. Man, for his part, is to simply hear and obey, period. There is, for example, no need for commentary or explication or critical studies of the Qur'an, for that text, Muslims believe, is direct from God, full stop. Yes, Christians believe that the authors of the Old and New Testaments were divinely inspired. Yet those authors did not simply transcribe, but acted freely and in full cooperation with the divine initiative: "To compose the sacred books, God chose certain men who, all the while he employed them in this task, made full use of their own faculties and powers so that, though he acted in them and by them, it was as true authors that they consigned to writing whatever he wanted written, and no more." (Dei Verbum, 11). Islam is a heteronomous religion; it posits that Allah is to be obeyed regardless of the directive, even if it goes contrary to reason and the laws gained by reason, such as the value and dignity of life, or the obvious evil of murder.
McCarthy sounds a strong warning about the logical path from relativism to indifference to capitulation to coercion (in form or another):
Most significantly, sharia is juxtaposed to freedom because it strangles individual liberty, the catalyst of progress. Sharia, we have noted, eschews our fundamental premises that the people are sovereign; that they may control their own destiny irrespective of any predetermined code; and that, while civil society may be profoundly influenced by spirituality, it is governed by secular laws.
Equal protection under those laws is the glue of a free, pluralistic society but sharia rejects it, elevating Muslims above non-Muslims and men above women. Our basic liberties fare no better sharia rejects freedom of conscience (apostasy from Islam is not merely a crime but a capital offense), freedom of speech (expression that casts Islam in an unfavorable light or sows discord among Muslims is a transgression as grave as apostasy), freedom of association, privacy, economic freedom, humane punishments, and the social commitment to tolerate and even appreciate most of our differences not extinguish them by violence and coercion.
Freedom is rooted in a correct understanding of the nature of God, accompanied by a serious but civil consideration of doctrinal differencesand the recognition that some are incompatiable and some are more reasonable, logical, coherent, and pro-human than others. Alas, relativism and indifference promise freedom from religon and doctrine, but merely lead to the embrace of false religions (or pseudo-religions, such as scientism and secularism). Which brings me, finally, to one my favorite quotes by Doroty Sayers, from her wonderful collection, Creed or Chaos?:
"Let us, in heaven’s name, drag out the divine drama from under the dreadful accumulation of slipshod thinking and trashy sentiment heaped upon it, and set it on an open stage to startle the world into some sort of vigorous reaction. If the pious are the first to be shocked, so much the worse for the piousothers will enter the kingdom of heaven before them. If all men are offended because of Christ, let them be offended; but where is the sense of their being offended at something that is not Christ and is nothing like him? We do him singularly little honor by watering down till it could not offend a fly. Surely it is not the business of the Church to adapt Christ to men, but to adapt men to Christ" (Creed or Chaos? 2425; see my article, "Dogma Is Not a Dirty Word").