A Protestant writer is saying what many Catholics should already know: our Church matters. Greatly.

Here’s Michael Gerson (former Bush speechwriter), in today’s Washington Post:

The occasion of a papal visit is a chance to take stock of the health of the Roman Catholic Church in America, which, like any church, reflects the flaws of its very human members. Many Catholics worry about the shortage of priests, nuns and vocational enthusiasm, complain about empty pews — about one in 10 Americans is a former Catholic — and anguish over sexual scandals in which clergy have, at times, appeared more interested in protecting the church than in demonstrating its ideals.

But members of a church older than any nation tend to take the long view. In the 10th century, Pope Sergius III grabbed the keys to the kingdom in an armed coup and promptly had two of his imprisoned predecessors strangled. His son, by his 15-year-old mistress, Marozia, eventually became Pope John XI. Marozia’s grandson, Pope John XII, stood accused of great crimes as well. According to one account, he “mutilated a priest . . . violated virgins and widows high and low, lived with his father’s mistress, [and]converted the pontifical palace into a brothel.” Those were the days to be a reporter covering the Vatican.

Catholics generally regard the survival and success of such a flawed institution as evidence of divine favor. The church has managed to outlive all of its scandals — and all of its critics.

But the Catholic Church has more than endurance on its side. It remains an indispensable institution, for several reasons:

First, despite charges of dogmatism, the church is the main defender of reason in the modern world. It teaches the possibility that moral truth can be known through reflection and argument. It criticizes what Pope Benedict XVI has called the “dictatorship of relativism” — a belief “that does not recognize anything as for certain and which has as its highest goal one’s own ego and one’s own desires.” “Being an adult,” says Benedict, “means having a faith which does not follow the waves of today’s fashions or the latest novelties.”

Secularism has traditionally taught that human beings will eventually outgrow religious conviction and moral absolutism — that skepticism is evidence of maturity. Benedict contends that modern men and women, unguided by reasoned moral beliefs, turn toward adolescent self-involvement. Their intellectual growth is stunted. In a world where all moral claims are seen as equally true and equally false — the world, for example, of the modern university — human conscience is reduced to biology or prejudice. Moral behavior may continue to ride in grooves of socialization or genetics, but moral assertions are fundamentally arbitrary — always trumped by a two-word response: “Says you.”

By asserting that the human mind can grasp moral truth, Catholicism also defends the reliability of reason against the superstitions of our time.

And this is important for a very practical reason: because a belief in human rights is also a moral conviction. Catholicism teaches that relativism and a purely material view of man have disturbing social consequences. “The criterion of personal dignity,” wrote Pope John Paul II, “which demands respect, generosity and service — is replaced by the criterion of efficiency, functionality and usefulness: others are considered not for what they ‘are,’ but for what they ‘have, do and produce.’ This is the supremacy of the strong over the weak.”

The point here is simple and radical: As the Catholic writer G.K. Chesterton argued, men and women are either created in “the image of God” or they are “a disease of the dust.” If human beings are merely the sum of their physical attributes — the meat and bones of materiality — they are easier to treat as objects of exploitation.

So Catholicism offers a second contribution: It is the main defender of human dignity against a utilitarian view of human worth. And the church has applied this high view of man with remarkable consistency — to the unborn and the elderly, the immigrant and the disabled. Individual views on issues of life and death vary widely, even within the Catholic Church. But it is a good thing to have at least one global institution firmly dedicated to the proposition that every growing child, every person living in squalor or in prison, every man or woman approaching death or contemplating suicide or trapped in profound mental disability, every apparently worthless life is not really worthless at all.

An institution accused of superstition is now the world’s most steadfast defender of rationality and human rights. It has not always lived up to its own standards, but where would those standards come from without it?