Shortly after Sept. 11, 2001, the eminent Palestinian-American intellectual Edward Said wrote a piece for the Nation magazine titled “The Clash of Ignorance.” He sought to rebut what he saw as a common fallacy in two articles: Bernard Lewis’ “The Roots of Muslim Rage” and Samuel Huntington’s “The Clash of Civilizations.”

Both pieces had gained a good deal of traction in the debate over the source of Muslim animosity, but in Said’s eyes both created a false dichotomy of two monolithic cultures, Islam and “the West,” standing in opposition.

“Certainly neither Huntington nor Lewis has much time to spare for the internal dynamics and plurality of every civilization,” Said wrote, “… or for the unattractive possibility that a great deal of demagogy and downright ignorance is involved in presuming to speak for a whole religion or civilization.”

Said could just as well have been writing about Robert Reilly’s new book, “The Closing of the Muslim Mind.” Reilly’s book adds to the ever-growing body of post-9/11 literature scouring history and theology in search of explanations.

Unfortunately, though, it contributes little of substance. Reilly, a self-proclaimed former “cold warrior” who is now a senior fellow at the American Foreign Policy Council, employs the type of reductionism Said was criticizing by casting a specific current of Islamic theology as the fundamental reason for the rise of “Islamism,” or Muslim radicalism.

Reilly traces the roots of contemporary radical Muslim theology to a 9th-century clash between two schools of thought, the Ash’arites and the Mu’tazalites. According to Reilly, the two differ in what he describes as “the status of reason in relation to God’s revelation and omnipotence.” Mu’tazalites urge humans to rationally try to understand the universe, while for Ash’arites, meaning is received from God and is therefore not subject to human interpretation. Ash’arism emphasizes God’s omnipotence, which for Reilly is equivalent to choosing power over reason.

The Mu’tazalites embrace Western ideals and for a time gain the upper hand, resulting in a flourishing of intellectual discourse. But the Ash’arites win out, at which point, in Reilly’s view, the “Muslim mind” begins to close.

This momentous event, according to Reilly, ossified Sunni thinking and prefigured the political systems of the Sunni Arab world. The principle of forfeiting human reasoning in favor of submitting to a divine mandate, deeply ingrained in Sunni society, does not allow for a democratic government that is dependent on robust debate and individual decisions. The prevalence of Sha’ria law leaves these societies bound to an outdated but unchallengeable legal code. In effect, Ash’arism’s emphasis on power leads to the violent nihilism of Islamism.

“The fact that the side of will and power won was the beginning of the decline of the Arab-Muslim world,” Reilly said in an interview. “The dysfunctional Arab world is the result of a deformed theology, and the answer to that problem is not an economic program. It’s a reconception of theology itself.”

But Reilly overgeneralizes in using Asha’rism as an explanation for a broad host of problems in the modern Muslim world. The apparent simplicity of the cause belies the variation and complexity of the problems. Ahmed El Shamsy, a scholar of Islamic history at the University of North Carolina, pointed out that while Mu’tazalism prevailed in Shiite Islam, predominantly Shiite Iran has not exactly flowered into a model democracy.

“After 9/11, these kind of single-cause arguments have really taken off,” he said. “I think they’re really problematic.”

The first section of the book analyzes Ash’arism, while the second section deals with the “aftermath,” citing anecdotes, skewed reports by the Arab media, writers and philosophers lamenting the plight of contemporary Muslims, and passages from various U.N. reports to demonstrate Islam’s “denigration and divorce from reason.” The connection between these examples and Ash’arism specifically becomes increasingly vague. It begins to feel like a blanket indictment of Islam in general — Ash’arism becomes the catchall source for ills from terrorism to inadequate education to human rights abuses.

It is true that the Ash’arite school of thought is a prominent feature of Sunni Islam and that its central thinker, Abu Hamid al-Ghazali, is a towering intellectual figure. But Reilly errs by making an absolute distinction between Mu’tazalism and Ash’arism as rational and irrational.

Frank Griffel, a professor of Islamic Studies at Yale University, said that “this is a very, very old argument,” and added that the two schools of thought are not irreconcilable but “two types of rationalism that are competing with one another.”

“There are things in Islam that are good and things that are bad, that we can all agree on,” Griffel said. “But to say everything would be better if the good side had prevailed is overly simplistic.”

While Reilly characterizes Islam as backward, his examples of its shortcomings are not unique to Islam. He quotes Arab media outlets that declared Hurricane Katrina to be retribution for humanity’s sins, but he omits the fact that Jerry Falwell and Pat Robertson made similar claims. He criticizes a disdain for the scientific method, apparently forgetting the push by conservative Christians to downplay evolution, perhaps the most significant scientific theory of our era. He writes incredulously of Arab troops believing God will protect them, neglecting to mention that presidents from Abraham Lincoln to Franklin Delano Roosevelt invoked God’s protection for the justness of American wars.

Reilly certainly invested a good deal of time and research into the book, but it feels as if he set out with an idea of what he wanted to prove and then found the facts and arguments to support it. For an author seeking a solution to big, complex problems, Reilly’s approach comes off as rather closed-minded.