Anyone who has kept up with politics lately is no doubt aware that certain intellectual attitudes and habits recur no matter what the subject under discussion. The rise of the Internet has democratized what was once the purview of the professional opinion journalist, policy analyst, or historian and thus made certain tendencies in the debate over domestic and international politics into full-blown categories of bad thinking. By my count, there are five main varieties of these without which there would be far fewer cable news channels, blogs, documentary filmmakers, and entries on The New York Times bestsellers list for non-fiction. All varieties are subject to overlap.

Tragic Manicheanism. The metaphysical battle between good and evil has many engaged spectators, some of whom are so chronically assured of evil's triumph that they appear to subconsciously root for it. This is the religious concept of original sin in political grammar. The tragic Manichean believes that everything one's own government or society does is bad and that all those who oppose it are axiomatically good. A very childlike worldview, it nonetheless caters to a large swath of people who believe that passion is a valid substitute for evidence.

The recently deceased historian Howard Zinn made tragic Manicheanism his academic legacy and personal fortune when he published A People's History of the United States, a bestselling volume on the occluded history of the republic written on behalf of its tired, poor, and systematically duped. As Michael Kazin, a leftist critic, has pointed out: "U.S. history for Zinn was… a painful narrative about ordinary folks who kept struggling to achieve equality, democracy, and a tolerant society, yet somehow were always defeated by a tiny band of rulers whose wiles match their greed."

Abolition, suffrage, civil rights, the welfare state are thus stray clearings of social justice in an otherwise uninterrupted vale of oppression. Zinn made no genuine attempt to explain why the underdogs—who represent 99 percent of the American population by his own estimation—have worn their servitude with shrugging acceptance, other than to say that they're easily "distracted" by wars and periods of patriotic fervor. This was no improvement on the Marxian notion of false consciousness. How could it be since Zinn's hero-victims transcend the narrow category of class to include anyone who's ever got a raw deal in the past 235 years?

The problem for the tragic Manichean is that, in the eternal struggle for the dominion of heaven, arguing that some angels quite like what the demons have done with interest rates and constitutional amendments is an unspeakable blasphemy.

Hysterical Conspiracism. What begins in a tradition of healthy skepticism culminates in a universal suspicion of anything presented as established wisdom. As Francis Wheen puts it in his recent book, Strange Days Indeed: The 1970s: The Golden Age of Paranoia, "You start by reading your horoscope in the newspaper; then you dabble in chakra balancing or feng shui, saying that it is important to keep an open mind; after a while your mind is so open that your brains fall out, and you read the Protocols of the Elders of Zion without noticing anything amiss."

No graduate of the Anglo-American university system in the past 60 years has lacked for an introduction to this pervasive theorizing of dark and hidden forces, which gallops across the political spectrum from right-wing fantasies about Freemasons to left-wing hysteria over the Warren Report.

The Jewish question, as Wheen rightly apprehended, seems to exercise over-active imaginations more than anything else. In the wake of the killing of Hamas militant Mahmoud al-Mabhouh in Dubai, the BBC Radio 4's PM program allowed one Gordon Thomas, author of Gideon's Spies, a book about the Israeli intelligence agency Mossad, to state the following: "They have a whole backup system called 'asylum.' These are people, local residents, Jewish people, who help the Mossad. It is estimated to be in the world about half a million—some people say a million; I tend to say it's about half a million—all of them Mossad people." Avoid all open windows at your next bar mitzvah.

The strategic advantages of the hysterical conspiracist are as follows:

1. He never risks appearing ovine or "naïve" because he is perpetually attuned to What Is Really Happening. What others might describe as pigheaded resistance to facts, he maintains as his unsullied record of un-falsifiable claims. As Johnson remarked to Boswell over dinner at the Mitre, "It is always easy to be on the negative side… If a man were now to deny that there is salt upon the table, you could not reduce him to absurdity." Trying to convince someone who insists that a plane did not fly into the Pentagon on September 11 is no easier.

2. Where he does advance an "alternative" explanation of events, the hysterical conspiracist usually maintains a small distance from absolute certainty—just in case. Hedge phrases or coy locutions such as "I'm not saying necessarily…" and "Isn't it interesting that…" exist to exonerate the conspiracist after the fact, preparing him for intellectual victory either way. Witness the qualifiers in this sample sentence from Tariq Ali's The Clash of Fundamentalisms: "[T]here exists no exact, incontrovertible evidence about who ordered the hits on New York and Washington or when the plan was first mooted."

3. The hysterical conspiracist forces his opponents to fritter away their time and resources in debunking his non-theories as "not even wrong." Popular Mechanics might have devoted a cover story to flying cars or Fermilab cyclotrons in March 2005. Instead it had to teach Rosie O'Donnell how steel girders melt in skyscrapers.

Moral Equivalence. Especially fashionable on the left, this mode of political thought assumes that it is the height of dialectical brilliance to subvert a democratic government's logic by "comparing" it to that of its totalitarian enemy. Usually bound to a poor grasp of the totalitarian's ethos and a cursory reading of its core literature, moral equivalence nonetheless masquerades as authoritative assertion, often to compensate for the sentimental insecurity of its purveyor. For instance, a lead sentence might run: "In his Short Course on the History of the All-Russian Communist Party, Josef Stalin describes the kulak in epidemiological terms, as a virus that poses the greatest threat to the organism of the socialist fatherland." Mock solemnity is maintained throughout until the inevitable anticlimax is reached: "The Scientologist is the kulak of the West."

Consider the following failed marriage of ideological motives that was recently ordained on a popular blog: "The theological justification for al Qaeda's wholesale slaughter of civilians was provided by Sayyid Imam al-Sharif, also known as Dr. Fadl, one of the founding fathers of al Qaeda… The legal [U.S. Justice Department] memos justifying torture aren't very different in terms of reasoning." Excepting that the latter form of reasoning, however flawed, didn't derive from 7th-century holy writ and the ultra-sectarian belief in spreading a caliphate to all corners of the globe and was not intended to justify a wholesale slaughter of civilians—sure, why not?

Triumphal Manicheanism. If the tragic Manichean's accoutrements are v-neck sweaters and the Collected Poems of Pablo Neruda, the triumphal Manichean's are varsity jackets and the collected works of Glenn Beck. This archconservative elder to his sunken-chested baby brother similarly traffics in either/or dichotomies of political thought, believing that everything his own government or society does is right and all those who criticize it—even from within—are radical communists. This may be because the triumphal Manichean once was one himself.

Indeed, the trajectory from left to right is typically charted by those with every intention of changing the substance but not the style of their ideology. Yesterday's fresh-faced Trotskyist screaming revolution in the street will be tomorrow's wizened Tea Bagger screaming revolution in the street.

The progression can work in the other direction, too, with triumphal Manicheanism being the starting point. Andrew Sullivan, a Thatcherite conservative import to these shores who has since made the steady creep toward hysterical conspiracism, was capable of writing, shortly after 9/11, "The decadent Left in its enclaves on the coasts is not dead—and may well mount what amounts to a fifth column." Having since repudiated this allegation, he now believes, predictably, that the actual fifth column came from neoconservatives within the Bush White House.

Charismatic Authoritarianism. Charismatic authoritarianism moors political fortune to a single figure whose radical promise is belied by his or her reactionary style. Fidel Castro, Mahmoud Ahmadinejad, Hasan Nasrallah, Ismail Haniyeh, Hugo Chavez, Muamar Qaddafi, Vladimir Putin and Bashar al-Assad have their cheerleaders and apologists, often in the same person who sees little contradiction in supporting such a promiscuous gallery of ideologues all at once. Just as Hitler and Stalin could for short time find a shared base of defenders in fascists and communists, so too can a Venezuelan socialist make common cause with an Islamic theocrat, allied by no more than a third world economy and an abiding hatred of the United States. The result is a kind of Unpopular Front of improvisatory opposition—all pomp, no principle.

Adherents of this category are characterized by easily misplaced affections. One such perennially fickle lover is British MP George Galloway, who champions both Saddam Hussein for his "courage…strength…indefatigability" in facing an international response to Iraq's takeover of Kuwait and Hussein's great nemesis Ayatollah Khomeini for issuing a death sentence against Salman Rushdie. Galloway's party, RESPECT, imploded in 2007 for its failure to blend the green flag of jihad with the red banner of the Socialist Workers Party, but that hasn't stopped his thralldom to all manner of "anti-imperialist" upstarts. He has mastered the language of Saladin or Che Guevara, depending on the audience and the need. Yet as numerous investigations into Galloway's "charity" work and his involvement in the UN oil-for-food program have uncovered, the charismatic authoritarian he admires most is himself.

Michael Weiss is a contributing editor at Tablet Magazine and a blogger for The New Criterion.