OUT OF the electronic ether, as if under cover of darkness, a “fifth estate” has emerged alongside the fourth, a new medium with the power to influence government, set the political agenda and shape public thought. Few saw it coming, but the sudden advent of the web-pamphleteer as a force in politics could not be timely: this is The Curious Incidence of the Blog at the Right Time.

A blog (from web log) is an online diary, an internet soapbox from which a blogger can pour down a varied flood of commentary, confession and contemporaneous reporting, periodically updated with fresh “posts” and linked to other sites on the web. Blogs are journals written in real time, simultaneously documenting, observing, criticising and participating. In 1999, there were perhaps 50 bloggers on the web; by next year, according to Perseus Development Corporation consultancy, some ten million blogs will have been created. Not since the 17th-century print explosion, which brought serial publication and pamphleteering to a genuinely mass market, has there been such an important shift in the way public opinion is created and shaped.

The US presidential election was the first in which blogs emerged as a force. On election night, more people logged on to the website of Matt Drudge, the godfather of bloggers, than turned to The New York Times website; exit polls appeared on blogs long before the television news channels dared to reveal them. But more than that, throughout the campaigns, bloggers monitored both the candidates’ claims and the resulting reporting, just as freelance pamphlet-writers of another age turned a fierce critical eye on the official version of events.

The rise of the blog marks the return of pamphleteering as a political force, and the revival of the citizen-journalist. Like pamphlets, blogs are short, vernacular, often scurrilous and ironic, ephemeral, topical, uncensored, unedited, polemical, easily accessible and cheap. Like pamphleteers, bloggers deliberately ignore distinctions between journalist, activist, pundit and private citizen; blogs open up a vast marketplace of ideas, in which the untrained can compete with the political and media elite, just as the spread of cheap paper printing offered opportunities for expression and criticism hitherto reserved for an educated few.

Like their paper predecessors, blogs are also often catastrophically wrong, a magnet for cranks, conspiracists, partisans and propagandists. Many, if not most bloggers, churn out pure pap; for every latter-day Jonathan Swift writing in cyberspace, there are thousands of teenage girls mewling inconsequentially about their boyfriends, acne and pop music. Ordinary people writing unpaid about things that matter to them may mark a crucial change in the information landscape; it can also be skull-crushingly dull.

But the best blogs are also the most widely read, precisely because other bloggers spot them and link to them; by a process of natural selection, the fittest blogs survive. The same was true of pamphlets in their heyday: Thomas Paine’s Common Sense was the most widely-distributed pamphlet of the American War of Independence, a truly revolutionary tract not only for its content, but also because it was copied and pirated on a massive scale. Within weeks of publication in 1776, seven editions of Common Sense appeared in Philadelphia alone, while other cities produced their own rival editions and imitators; this was the 18th-century version of the über-blog with countless hyperlinks.

Bloggers, like the earlier pamphleteers, tend to operate outside and often in defiance of the established media, yet they exert a formidable and increasing influence on mainstream news coverage: when Senator Trent Lott made a racist remark at a birthday party in 2002, the online bloggers turned a story largely ignored by other media into a full-blown scandal that resulted in Senator Lott’s resignation as senate majority leader; pressure to investigate President Bush’s National Guard Service came principally from bloggers; the postings of Salam Pax, the 29-year-old Iraqi architect known as the “Baghdad Blogger”, were required reading for anyone interested in understanding the second Gulf war.

The art of political pamphleteering was dormant for most of the 20th century, which prized objectivity above all, and insisted on a strict division between analysis and reportage. Writing in 1943, George Orwell bemoaned what he saw as the absence of pungent pamphleteering: “We live in a time when political passions run high, channels of free expression are dwindling, and organised lying exists on a scale never before known. For plugging the holes in history the pamphlet is the ideal form.”

The blog has its limitations, of course. Orwell believed that most pamphlets were “written by lonely lunatics who publish at their own expense”; this is doubly true of blogs, costing virtually nothing. Today’s electronic pamphlet travels much farther and faster than its precursor, but the paper lasted longer and left a distinct trail. Even the best blogs are prone to coffeehouse-clamour, too busy bawling at one another to be audible.

Yet web logs have emerged into more than a mere cacophony of newfound but uninformed voices. Not only do blogs plug holes in emerging history, they may even change it by reaching the parts that freedom does not. In Iran, several anti-government newspapers have been closed down, but the Iranian blogosphere is booming, with 6,000 separate blogs. Farsi is now the fourth most widely used language on web logs.

Censors become impotent when every Joe Bloggs is a potential blogger, and anyone with a computer, an internet connection and an opinion has the chance to become a right Paine.