When I recently gave a lecture entitled "Does Religion Cause Violence?" at a college, someone scrawled across a poster advertising the lecture a single word - "Duh!" The idea that religion has a peculiar tendency to promote violence has achieved the status of truism in Western societies. It is currently advanced with great vigour by the so-called "New Atheists."

No one has put the case more forcefully, more absolutely, than the late Christopher Hitchens. In his influential best-seller God is Not Great: How Religion Poisons Everything, Hitchens locates violence at the very heart of religion. What actually counts as religion, however, is slippery. It seems like the most appropriate homage I can pay to this man is to scrutinize his own claims about religion, just as he insisted on scrutinizing those of others.

As is well-known, Hitchens indiscriminately criticizes Christianity, Islam, Buddhism, Confucianism, Judaism and Hinduism. In the face of objections that atheist regimes like those of Stalin and Kim Jong-Il can be extraordinarily violent, Hitchens simply includes them under the rubric of religion too. Totalitarianism aims at human perfection, which is essentially a religious impulse, according to Hitchens. Religion poisons everything because everything poisonous gets identified as religion.

At the same time, everything good ends up on the other side of the religious/secular divide. Hitchens says of Martin Luther King Jr, "In no real as opposed to nominal sense, then, was he a Christian." Hitchens bases this remarkable conclusion on the fact that King was nonviolent, and the Bible preaches violence from cover to cover. What is not violent cannot possibly be religious, because religion is defined as violent. So Stalin is religious but Martin Luther King is not. If the latter is a bizarre claim, the former actually has some pedigree.

There is a large body of scholarship that identifies Marxism as a type of religion. Such scholarship assumes a "functionalist" definition of religion, where religion is identified not by doctrines, such as belief in God or gods, but by the way it actually functions in a society. Ideologies and institutions that provide an overarching symbol system of the meaning and end of human life are considered religions by functionalists.

Hitchens would be in respectable scholarly company if he applied a functionalist view of religion consistently, but for Hitchens "religion" only applies to things he doesn't like.

There is an extensive body of scholarship that explores the prevalence of civil religion in the United States which, as Robert Bellah says, "has its own seriousness and integrity and requires the same care in understanding that any other religion does." Scholars have explored the peculiar myths, symbols, and sacrifices that surround the flag, for example. Hitchens ignores all this, and only uses a functionalist definition of religion when it suits him.

Despite his sabre-rattling for the Iraq War and his evangelical desire to spread American-style liberalism abroad, Hitchens' militant secularism escapes scrutiny because it doesn't count as religion. In Hitchens' scheme, only certain kinds of atheism do. We should, however, resist the temptation to dismiss Hitchens as being peculiarly confused or disingenuous. In fact, this type of noise is the norm when it comes to discussions of religion and violence.

Most arguments about religion and violence assume a "substantivist" definition of religion, whereby religion is defined by the substance or content of beliefs. Commonly substantivists start with God or gods, but soon recognize that the category must be broader to include the many forms of Buddhism, Confucianism, and Daoism that don't involve gods. More inclusive definitions like belief in "transcendence" or "soteriology" are floated to try to include Buddhism and other beliefs and practices.

The problem is that once the definition of religion is expanded to include all the things substantivists want to include, it becomes difficult to exclude all the things they want to exclude. "Transcendence," originally associated with the Judeo-Christian Creator God, can be made vague enough to include Buddhism, but if it is, it becomes hard to exclude things like nationalism. Similarly, if "soteriology" can include Confucianism, then it is hard to exclude Marxism. For this reason, many scholars prefer functionalist definitions.

In the wake of rolling blackouts in California in 2001, one of the architects of the deregulation of California's electrical utilities was quoted in the New York Times expressing his belief that free markets always work better than state control - "I believe in that premise as a matter of religious faith." Why not take him at his word? A functionalist would say that if it looks like a religion and acts like a religion, then it is a religion.

If applied consistently, functionalist definitions of religion have the advantage of levelling the playing field among all types of ideologies and institutions that claim loyalty from people. When studying violence, it helps to see that people kill for all sorts of reasons, and professed beliefs in God or gods are not necessarily more productive of violence than other beliefs.

Some say that beliefs in gods are more absolute than beliefs in merely mundane realities like the market or the nation. But the fact is that people treat all sorts of things as absolutes. This insight is not new to functionalists - it is what the Bible calls "idolatry." Even if people do not actually bow down and pray to a stack of dollar bills, Mammon can still be their god. How many people have been sacrificed to the "invisible hand" of the market? As Eduardo Galleano said of his native Uruguay during the era of free-market military dictatorships, "People were in prison so that prices could be free."

Most American Christians would recoil at the idea of killing for Jesus Christ, but most American Christians believe that organized slaughter on behalf of the nation is sometimes necessary and praiseworthy. This is not to say that people do not do violence on behalf of Christianity, Islam, Buddhism, and so on. They do, and this fact must not be ignored. It is simply to say that so-called "secular" ideologies and institutions are capable of promoting just as much violence as so called "religious" ones.

The myth of religious violence helps create a blind spot about secular violence. A sound approach to the study of violence would be resolutely empirical, investigating the conditions under which any kinds of ideologies and institutions produce violence - not just jihad and the sacrificial atonement of Christ, but also the "invisible hand" of the market and the belief that liberalism and secularism are the destiny of the whole world.

In such an investigation, is the religious/secular distinction helpful at all? Functionalism helps reveal the fatal flaws in substantivist definitions, but functionalism has problems of its own. In clinging to the term "religion," it casts the definition so broadly as to make it synonymous with any idea or practice that people take very seriously. It also assumes, like substantivism, that religions are really "out there," a basic transcultural feature of human life.

But in fact the religious/secular distinction is a modern Western creation. It has a history that is tied up with the creation of the modern Western nation-state. Rather than trying to determine, once and for all, if, for example, Confucianism really is or is not a religion, much more is revealed by asking why the category was created in the first place.

Wilfred Cantwell Smith's landmark study The Meaning and End of Religion demonstrated that in the pre-modern West and in non-Western cultures previous to contact with the West, there was nothing equivalent to what we think of as religion, as a discrete activity separable from culture, politics, and other areas of life.

The ancient Romans employed the term religio, but it covered all kinds of civic duties and relations of respect that we would consider "secular." As St Augustine says in The City of God, "We have no right to affirm with confidence that religion (religio) is confined to the worship of God, since it seems that this word has been detached from its normal meaning, in which it refers to an attitude of respect in relations between a man and his neighbour."

In the medieval era, the religious/secular distinction was used exclusively to distinguish between clergy who belonged to an order and diocesan clergy. (Catholics still refer to joining an order like the Dominicans as entering the religious life). There simply was no discrete activity called "religion" that was separable from "politics" or "culture."

The religious/secular distinction as we know it today was a creation of the early modern struggles for power between ecclesiastical and civil authorities. In the creation of the modern sovereign state between the fifteenth and seventeenth centuries, "religion" was invented as a universal, essentially interior and private, impulse that is essentially separate from politics and other "secular" concerns.

Henceforth the church's proper area of concern would be essentially alien from politics. The idea that "religion" is a transcultural and transhistorical impulse makes the separation of religion and politics appear natural and inevitable, not a contingent arrangement of power in society.

The religious/secular distinction was subsequently exported to non-Western cultures during the process of colonization. In their initial encounters with the non-Western world, European explorers reported, with remarkable consistency, that the natives had no religion at all. Once colonized, however, the category "religion" became a powerful tool for the classification of native cultures as essentially distinct from the business of government.

"Hinduism," for example, a term first used in 1829, became a religion in the course of the nineteenth century, despite the fact that it encompassed the entire Indian way of life, everything we would include under culture, politics, religion, and economy. If, under British rule, Hinduism was a religion, then to be Indian was to be private, and to be British was to be public. This is why many contemporary advocates of Hindu nationalism - especially the powerful Bharatiya Janata Party - reject the classification of Hinduism as a religion.

For similar reasons, the Chinese government excludes Confucianism from its official list of religions in China. It is seen as an expression of the national character, superior to "religion," which is private and otherworldly. What counts as religion and what does not depends on how power is configured in any given society, including our own. The idea that "religion" is susceptible to violence, in ways that "secular" ideologies are not, authorizes certain kinds of power.

Today one of the most relevant examples of this can be seen in the ways that Westerners view the Muslim world. As John Esposito points out, to apply the Western term "religion" to Islam immediately marks Islam as an "abnormal" religion, because they do not "properly" separate religion from politics.

Secularism is normative, and Islam is thus seen as inherently irrational and volatile. Any analysis of American dealings with the Muslim world - the 1953 coup in Iran; support for the Shah, the Saudi royal family, Hosni Mubarak and other oppressive regimes, support for Israeli occupation of Palestinian land, Abu Ghraib, Halliburton, and so on - are all ignored in favour of the "deeper root" of the problem - "religion."

The irony is that the myth of religious violence can be used to support secular violence. Despite his attempt to recruit Martin Luther King to his side, Hitchens has some approving things to say about killing people. "And I say to the Christians while I'm at it, 'Go love your own enemies; by the way, don't be loving mine'." Hitchens goes on to write, "I think the enemies of civilization should be beaten and killed and defeated, and I don't make any apology for it."

For Hitchens, the Iraq War is part of a broader war for secularism, and the game is zero-sum. "It is not possible for me to say, Well, you pursue your Shiite dream of a hidden imam and I pursue my study of Thomas Paine and George Orwell, and the world is big enough for both of us. The true believer cannot rest until the whole world bows the knee."

The true believer Hitchens has in mind is the Islamist. But Hitchens' message is that the true believer in secularism can also not rest until the whole world has been converted to secularism - by force, if necessary. The myth of religious violence is a way of saying, "Their violence is essentially irrational and fanatical. Our violence is essentially rational and necessary."

A more peaceful world depends on doing away with such binaries, and taking a hard look both at Muslim-inspired violence and at the things - flags, markets, "freedom" - to which we sacrifice lives.

William Cavanaugh is Research Professor at the Center for World Catholicism and Intercultural Theology at DePaul University, Chicago. He is the author of Torture and Eucharist: Theology, Politics, and the Body of Christ, Being Consumed: Economics and Christian Desire, The Myth of Religious Violence: Secular Ideology and the Roots of Modern Conflict and most recently Migrations of the Holy: God, State, and the Political Meaning of the Church.