NOWADAYS, WE WANT the truth. Suddenly, it seems, we are no longer content to be sceptical and laconic and sophisticated, or to take the line that there are many kinds of truth and that it all depends on how you look at it, and on who is doing the looking. Politicians and journalists, for example, long assumed by a knowing public to belong to professions that not only display but positively require a flexible approach to the facts, now find themselves being scrutinised and investigated to establish whether or not they have been telling lies. The Blairs - Jayson of The New York Times and Tony of Her Majesty's government - cannot, in their recent tribulations, have missed the irony of this dramatic shift. Where once we tolerated, even celebrated, shading and nuance and the need, sometimes, to elaborate and select and even invent in order to arrive at a truth of a kind that told us far more than the mere facts ever would, now we just want to get down to those plain unelaborated facts and to establish what really did happen, or is currently happening, or is about to happen.

Quite recently, that would have seemed an impossibly naïve ambition. Truth was a destination we were unlikely to reach - the journey was all, and along the way we would be confronted by many versions of what happened, each with its own validity, its own unique perspective. But things have taken a turn. In one of the more interesting and rapid social changes to have occurred in the new century, there is a growing impatience with the sophisticated and politically savvy approach to the world. There is a new post-pomo mood in the air, a kind of willed confidence that the facts are indeed out there somewhere, waiting to be told. The easy sophistication that assumes that nothing is what it seems - truth is a delusion, everybody more or less lies, 'he would say that, wouldn't he' - is being rejected as itself naïve. The explanation, the real truth, must be out there somewhere; it is merely a question, or so it seems, of locating among all the chatter the voice that is telling us how things really are.

It is easier said that done. Whom can we trust? It seems that everywhere we are being betrayed: by journalists who file stories from places they have never been; by politicians and public figures who say merely what it is expedient to say and who always manage to avoid answering the question; by historians and political commentators who fiddle with their sources or get them jumbled so that they can't remember whether the words on the screen are theirs or someone else's; by memoirists who make things up. We feel particularly let down by the last, because the memoirist comes to us as the pure voice of memory. In reality, the memoirist is probably as dependent on external sources as any writer who is attempting to recover the past, but we do not see it that way. The recollections of the memoirist or the autobiographer rely for their authority not on a wealth of research and attributions, but on our confidence that he or she was there and this is what they saw. If the memoirist can't tell us what happened when they were there and we weren't, then who can? The memoir is, if you like, the individual's truth, although we are prepared to accept - in fact we assume - that others (the mother, the brother, the lover) may well have seen things differently. Within those constraints, we take the memoirist on trust, yet repeatedly we find that our trust is misplaced.

The memoir is one of the fastest growing genres of the times. The subject matter is the self, which means that everyone, potentially, has something to write about. (Write what you know, runs the adage, and more and more people are following up on it.) But there is a trap. Readers read the lives of other people because they really happened. If they find out that they didn't happen, all hell can break loose. We may be moved by a story of suffering, or of the triumph of the human spirit over adversity, but if we find that it never really happened, or not in the way that the writer says it did, we feel duped. Such scandals abound, in which memories are exposed as invention and memoirists as fabricators rather than recorders.

Once it is revealed that they are not what they purport to be, autobiographies are pulped or die on the shelves. When Norma Khouri's Forbidden Love (2003) - in which she told of events that took place when she was growing up, in a country she had in fact left when she was three - was identified (by a persistent investigative journalist) as fiction rather than fact, you could feel the anger and resentment in the air. Nobody, interestingly, pleaded the standard defence: the one that would have run along the lines of 'it may not have been true, but it was nevertheless a kind of truth'. This was not simply because Khouri's subject matter, the position of women in Muslim countries, was one in which invention was seen as particularly inflammatory and particularly opportunist, but because she had negated the very reason why people had bought her book in the first place. They bought the authentic voice, and found out too late that they had been sold defective goods.

It is hard to write anything about actual events without fibbing or getting things slightly wrong, even if inadvertently. Most readers continue to accept as a given the elusiveness of unimpeachable accuracy. But what is new is the sense of outrage, rather than mere eyebrow-raising, in the face of evidence presented to readers that they have been deliberately deceived. With that outrage goes a determination to expose such duplicity wherever it occurs, and to characterise it as just that - not licence or oversight or legitimate reworking in order to make a point or the natural consequence of impossible deadlines, but downright, unforgivable duplicity. And so Jayson Blair - who, according to Seth Mnookin, in his Hard News: The Scandals at the New York Times and Their Meaning for American Media (2004), 'fabricated or plagiarised' three dozen stories in one six-month period alone - is seen as simply the most spectacular example of an epidemic of deliberate misinformation and misinterpretation against which we must be increasingly vigilant. Blair - who appears to have stayed at home typing, surrounded by fast-food cartons, when he was supposed to have been on the road, discovering things from source - committed a double sin of deception. He invented, and he copied, and we see both as equally reprehensible.

In an absorbing piece in last December's London Review of Books called 'Love and Theft', Mark Ford speaks of the relationship between plagiarism and poetry, and the difficulty of making sharp distinctions between what can be confidently defined as theft, and what might be better called borrowing or 'bricolage', terms that reflect the underlying 'truism that all writing depends on other writing'. Some of the tolerance and even celebration of borrowing that we have increasingly come to see as integral to cultural production and cultural commentary - is there an art historian, for example, who could stand up to the challenge of deleting the word 'appropriation' from their professional lexicon? - has also had a profound influence on our reading of purported truth. It helped to make us tolerant of lapses in historical accuracy or attribution in all forms of writing, not just poetry and fiction (or, for that matter, paintings or films) but also in the kind that claimed to document real events, in real places, affecting real people. We also understood, or thought we did, that the word 'real' was itself a problem, meaning different things to different people. And yet, with amazing speed, we have begun to withdraw that tolerance in favour of a sterner line altogether. We want the real truth, and we don't believe we are getting it. Distrusting those who claim to tell things as they are, we now seek out the authentic voice, the one that is unencumbered by the structures and conventions of our institutions, or by the unstated rules and the secret handshakes of the media and the academy.

It is a turn of events that has given a nasty shock to many who have been caught, in the middle or the twilight of their careers, by this trick played on them by the Zeitgeist. Plagiarism, which we had grown fairly relaxed about, seeing it as merely one end of a continuum that included borrowing and appropriation and nodding vaguely in the direction of, is back, and the vengeance is ours. There are those who say that it is too late, that we are all plagiarists now and the battle - for the survival of the individual voice - has been well and truly lost in the welter of information and sources and precedents and sheer, unending product that overwhelms us, making it impossible to keep track no matter how vigilant we are. Yet most of us, rather than giving up and just going with the flow, are standing firm, demanding the truth and identified authorship, with all sources, and all voices not the author's own, duly noted. In his book on 'facts, fictions, fraud' in the practice of history in America, Past Imperfect (2004), Peter Charles Hoffer quotes the popular historian Stephen Ambrose attempting to explain why he may have inadvertently exposed himself to charges of plagiarism: '"I do my writing at a computer, surrounded by my research … documents of all kinds, books. I mix them to describe an incident. Usually I have five or more transcripts, plus copies of documents and books on the table. I take material from them all."' It is a poignant image, not simply of a writer who has lost control of his material, but of the material taking over the writer, muffling his own voice. In the case of Ambrose, intention is difficult to establish, but for the plagiarism police, ignorance is no defence.

The new intolerance of such lapses brings with it a sharpening of the critical functions, an unwillingness to be snowed. Readers are on the lookout. They are no longer happy to see reading as a way of joining in the fun of the creative process, participating as a good sport does in generating the meaning of the text, playing their assigned part. These new refuseniks are seriously critical, and they are not participating in the text, or not at least in the texts that are presented to them under the imprimatur of publishing houses or the 'mainstream media'. They are not content to make allowances, to see things in context or keep them in perspective. They are not, moreover, happy to take their place as readers in the space that the text creates, or indeed to do any of the other things that modern, street-smart readers are supposed to do. They are rejecting the texts that are being offered to them, in favour of producing their own. Readers are becoming writers, adding their own voices to the mix. In short, they are blogging.

According to the Pew Internet and American Life project, 'by the end of 2004 … 7% of the 120 million U.S. adults who use the internet … have created a blog or web-based diary'. These figures are no doubt rubbery, but they are indicative of a huge increase in the numbers of people adding their individual voices to the web, not only in the US and not only in English, either. Blogging is big from China to Iran, where according to Daniel W. Drezner and Henry Farrell in Foreign Policy (November/December 2004) 'Farsi is the fourth most widely used language amongst blogs worldwide'. The growth continues, with more and more writers committing themselves to publication, and, if they are lucky, to readers.

It has always been a pretty safe bet that, however many writers there might be practising their craft at any one time, as long as they could clear the publishing hurdle and get their words into a book, newspaper or newsletter, then more people than their best friends were going to read what they wrote. The total number of readers, in other words, was always going to be greater than the number of writers. Now, for the first time, it is possible to envisage a world in which that comforting ratio may not apply, and in which you can count yourself fortunate if your best friend reads what you write. Notwithstanding the extraordinarily high readership enjoyed by a very few of these millions of blogs, the majority speaks to what the Perseus Blog Survey describes as 'nanoaudiences'. Under the system of unmediated and unauthenticated publication that the web provides, and with things going the way they are, we could soon have more published writers than there are readers to read them. For some sites, this means that there will be no readers at all, and you can't get more nano than none.

This may not be a bad thing, if it means more people will take the trouble to formulate their own thoughts in writing, rather than accept unquestioningly the supposedly authoritative voice of someone else. But just as the early days of the mobile phone had untold numbers of people calling home to say 'I'm on the train', the online diary - the blog - is an opportunity to say, 'I'm here and I'm writing', and not a great deal else. That is at least a step forward from the personal home page, which allowed people to say the 'I'm here' part but otherwise gave little sense of progress or movement. There was always the feeling with a personal home page that notwithstanding all the stuff about cats (a favourite topic that survives and prospers in the world of blogging, to the extent that the term 'kitty blog' is now applied to the practice of writing about nothing) and the kinds of personal details that were meant to give an impression of a lived life, no one was actually at home when you called. The owner had moved, or was out for the day. Either way, there was a static quality to the home page that spoke, like a photograph, of the past rather than the present. The site was invariably 'under construction', which held out the promise of more to follow, but visitors could not be confident that work would resume. So why return when nothing much was going to change?

The blog, by contrast, is of the here and now, endlessly supplemented by new thoughts and new observations. The fact that it is under construction is not a defect, but lies at the core of its appeal. It holds out the promise of eternal life, a never-ending text, a voice that will never be silenced. It is amazing how many blogs continue to be updated, on an hourly, daily or, at the most, weekly basis; long after you would have expected the blogger to grow tired of it. It is also true that this impression of endless updating is far from being the whole story; blogs, like home pages before them, are abandoned by their creators at a rate of knots, but not yet fast enough to outweigh the numbers of new entrants eager to have their say. No doubt the day will come when the total number of postings will start to decline, and just as the vast majority of people who begin diaries and stamp collections never follow through, so perhaps the balance will shift, with blogs disappearing at a faster rate than they are being replaced. But that day is not here yet.

We are definitely in a growth phase, even if there is much talk in cyberspace about the impending end of the personal blogger, as the big boys and girls in industry, advertising and politics, not to mention the media, continue to cotton on to its (largely unspecified) commercial and organisational potential. The Vice-Chairman of General Motors, for example, hosts Fastlane, where you can learn more than you may need to know about the new Pontiac Solstice; and Margot Wallström, the European Union's Commissioner for Institutional Relations and Communication, posts regularly, displaying a nervous resilience in the face of some of the comments she receives: 'Thanks to all of you who have read and reacted to my blog! And I guess it's in the human nature to react more emotionally to the negative comments. The one I liked the most was the guy who wanted my recycled paper bag to throw up in! Funny!'

Blogs abound, and so do commentaries on the blogging phenomenon. Some of these commentaries confine themselves to exhortation - blog or die, in effect - but most take one of two lines. The enthusiasts identify a social revolution of overwhelming significance that will change for the better the way we do just about everything. For the sceptics, on the other hand, the barbarians are at the gate, although like all barbarians, they will be repelled eventually, if we just learn to take the long view. Hugh Hewitt, the conservative US columnist and hyperactive blogger, takes the former line in Blog: Understanding the Information Reformation That's Changing Your World (2005). Hewitt sees it as imperative (there are lots of imperatives in Blog) that everyone, from pastors to potentates, screws their courage to the sticking place and enters the blogosphere. For pastors, he suggests a number of must-read blogs they will need to be familiar with if they are to identify the issues being raised by the voices out there (a limbering-up process that may also prepare them to become one of those voices themselves). But once the issue has been identified, what then? Get the congregants together, suggests Hewitt, and 'convene a study session and round-table on the issue', a strategy which, on the face of it, does not seem likely to achieve a great deal. Like many enthusiasts for the blogging revolution, Hewitt is much clearer on the journey than he is on the destination.

Others see the journey ending in tears. George Packer, writing in the May/June 2004 edition of Mother Jones, sees blog postings as 'atomised, fragmentary and of the instant'. He characterises them as 'little spasms of assertion', capturing in that unkind phrase the sense that even a small amount of time spent trawling the sites quickly conveys that everyone is speaking at once, anxious to have their turn, whether or not anyone is really listening. But the old media can be much harsher than this. 'The whistle-blowers, e-babies, inside-outers, wonkettes, quacks and cranks have globalised Speakers' Corner,' says Simon Jenkins in Times Online (11 March 2004). 'They have rebuilt the Tower of Babel and put microphones on top of it.' Whether they are for or against, and whether or not they are bloggers themselves, the commentators tend to focus as much on the act of reading blogs as on writing them, because it is by reading them that we find out what is going on. To enter the blogosphere is to get in touch with the authentic voice. It may or may not be a voice that says anything one really wants or needs to hear, but that, in a sense, is a second order question.

For some, the voices contain gems that link us to what people really think and help us to understand the world as it is, unmediated by spin. For others, it is babble; impossible to ignore, but babble all the same. Hewitt asks a potentate, in this case the Chairman of the US Joint Chiefs of Staff, whether he reads the military blogs, the online journals kept by members of the armed forces. 'He said he didn't but he knew he had to find time to do so.' The Chairman is under pressure. There is a world out there, and he has to find the time to monitor it, or at least to read the reports of somebody who is charged with monitoring it for him, all the while continuing to hold down his day job.

Something of the same tension, between the old and the new way of understanding what is going on, is contained in an exchange recorded by Michael Totten at michaeltotten.com between himself and Christopher Hitchens. Totten asks Hitchens if he reads blogs. '"Not really,"' says Hitchens, '"I could spend all day reading blogs and not get anything done."' Totten puts him straight. '"You can't afford not to read blogs,"' he says. '"Because of who you are and what you do for a living, you'll be hopelessly behind if you don't."' It is a genuine fear that is being expressed here, one with a long pedigree; not of terrorism or global warming or of any of the other dangers that we have created and now cannot control, but the fear of being left behind, of missing the train.

Blogging seems to offer a channel for the direct authorial voice, reasserting qualities like authenticity and originality that have long since been presumed lost in a cloud of qualification and allusion. The tone is often impatient (those 'little spasms of assertion'), concerned not so much to persuade as to convey the depth of authorial feeling and of the personal point of view. The blog posting catches the moment, but, like the moment, it does not last. Reading through the archives of even the most lively and engaging blog can be an enervating experience. The blog is of the here and now and does not translate well into historical narrative in the way that, say, a diary or an exchange of correspondence from an earlier time can stand as a story on its own. Simon Garfield, writing about the blogging phenomenon in the Sunday Observer (4 April 2004), picks up on the connection between archived blogs and the Mass Observation movement in Britain in the 1930s, in which records were kept by armies of volunteers of their own and other people's daily lives and opinions, thus contributing, or such was the plan, to an anthropology of the times. Reading the fruits of Mass Observation now is a bit like trawling backwards into a blog, inducing as it does the same kind of initial fascination that is quickly - in some cases almost instantaneously - overtaken by fatigue.

Tony Pierce, who posts at tonypierce.com and who won the 2005 Bloggie award for the year's best piece about blogging, tries to warn neophyte bloggers about the fatigue factor and how not to induce it in anyone who might otherwise be prepared to listen to what you have to say. 'Nobody gives a shit,' he warns, 'what the weather is like in your town, nobody wants to change their cursor into a butterfly (and) nobody gives a rat ass what song you're listening to. Write something Real for you, about you, every day.' This excellent advice has, by and large, fallen (if it has fallen at all) on deaf ears. Blogs, like home pages before them, are choc-a-bloc with favourite songs and favourite films, as though taste were the key to the self. Indeed, the authentic voice that so many commentators detect in the blogosphere - the one that speaks from Brisbane or Baghdad and tells us what is happening on the ground - is remarkably coy when it comes to actual biographical detail. The standard biographical templates favour brevity: age, gender and not much else. The voices, by and large, are left to speak for themselves. And in the absence of any reliable form of authentication, we invest our trust in the voices, forgoing the caution and the scepticism that we increasingly and ever more unforgivingly apply to information that comes to us from other, traditional sources.

The motivation, like the biography, of the individual blogger is hard to ascertain. Various questionnaires circulate - some with greater prestige than others given the stratified nature of the world of blogging - in which the attempt is made to get people to define what it is that keeps them at the keyboard, sometimes for hours in the day, posting, linking, commenting and generally having their say. Norman Geras, an academic who has crossed over to the blogosphere, offers at normblog.com an occasional series of profiles of online diarists who have caught his attention. Inevitably they are ones who gravitate to his world view (an energetic combination of old left and neocon), whom he has discovered or who have discovered him in the way that bloggers of like mind do. But even allowing for this degree of similarity in outlook, there is still a remarkable consistency in the responses to the question Geras asks them all: 'why do you blog?' It 'stops me shouting at the radio', says one. It's 'an alternative to shouting at the TV', says another, or 'it's better than shouting at a newspaper', says a third, thus ensuring that the traditional media are pretty well covered. It isn't all about transferred aggression, though. Blogging is 'a form of self-talk', 'a unique opportunity to exercise one's right of free expression', 'a way of making your voice heard'. For Chris Young, who posts at Explananda.com, blogging serves 'to remedy nagging esprit d'escalier', a phrase that captures the nature of blogging as both a rejection of authority and a response to it, a way of talking back while talking to yourself.

The unmediated nature of the blogosphere - the millions of voices all speaking at once - attracts and disappoints us at the same time. We are attracted to these authentic, untrained voices because we have grown to distrust those who speak to us under some kind of professional imprimatur: journalists, academics, writers, experts. We distrust narrative and explanation because we distrust the narrators and the explicators; we have been caught out too many times. Online diaries, by contrast, are immediate, visceral and unpolished, the qualities that strike us as true. They appear to link us to the source, creating a direct line, via the medium of the blogger, from experience to reader. The underlying irony represented by the vast number of blogs with 'pundit' in the title is that bloggers see themselves by their nature as anti-punditry, or rather that they have as much claim to punditry as anyone else and possibly more. It is this quality of assertion, rather than the anger that many have identified as characteristic of blogs but which in fact applies to only a relatively small number of them, that links all the different kinds of blogger together - the pundit bloggers, journal bloggers and even kitty bloggers. They are asserting their own voices because they have something to say that is as real, in fact more real, than the voices that are transmitted by means of old technology.

This faith in the authenticity of the blog survives abundant evidence to the contrary; indeed, it can scarcely come as a surprise, when the web is so conducive to impersonation, that bloggers will often turn out to be not who they claim to be. What is surprising is the laconic reaction to these kinds of revelations. When it was found that the author of bizgirl, one of the Bloggie finalists for 2005 in the category for Australia and New Zealand, was not a girl at all, the revelation caused hardly a ripple among its readers, or indeed anyone else who happened to notice. This relaxed attitude to fabrication, contrasting as it does so sharply with the reaction to historians or mainstream journalists who are similarly exposed, suggests that bloggers are judged by different rules, in which the impression of directness and authenticity is what actually counts. Any dissatisfaction or uneasiness that we feel with what the blogosphere has to offer lies not, as we might expect, in the fact that we are hard pressed to tell the difference between truth and fable. It lies in the sheer, unmediated unmanageability of it all.

There is too much stuff out there, offering opinion, observation, irony and sometimes anger, with none of it tying together. Attempts to map the patterns of the blogosphere - whether through sites such as Technocrati which give us the subjects du jour, or Slate or the Columbia Journalism Review (via CJRDaily) and others like them that regularly dip into the topics that are doing the rounds and sum up what people are saying - are deeply unsatisfying. Like the blogs themselves, they provide observation without structure, dialogue without plot. Blogs are not really conducive to analysis and reflection. By their nature, they discourage us from looking back. The pattern of movement is always forward; fast forward in fact. A typical blog will include its archives in a column on one side of the screen and its links to other blogs on the other. One roll for the past, one for the future. Faced with this choice, the click is almost invariably forward to another site, another view, another voice, rather than back to something as old as yesterday. The sites have names to conjure with: guns and butter and little green footballs and shelley on the telly; and so these titles run onwards by the thousand, combinations of whimsy and laboured eccentricity that belie, often, the seriousness of the postings. So attuned are we already to this ironical convention that it is something of a shock to find, for example, that blogs called Life Insurance and Used Cars are actually about life insurance and used cars.

No blog is an island. Links abound, connecting us not only to other blogs but to sources (by means of 'hat tips') and references, to comments and after that to comments on the comments. Amid this cacophony, the voice of the individual blog retains its distinctiveness, but only just. It seems forever in danger of merging into the larger voice disappearing into a sea of links and references, not waving but drowning. Writers such as William Burroughs, who hyped his cut-up method in the good old days when it was not very difficult to challenge our staid notions of what it meant to read, cannot have anticipated just how cut-up things would get. The metaphorical truism - that nobody reads exactly the same text - has become a literal one. Nobody reads the same blog, because every individual reader flies off in a different direction, pursuing links or selecting a title at random from the blogroll, enjoying being caught up in the rush, until he or she gets tired of it and breaks for a cup of coffee or a breath of fresh air.

In the end, blogs are no more authentic or true than the other kinds of writing against which we are taking such a hard line. But what they do have is a quality of naturalness, immediacy and brashness that seems to speak to us directly, telling us that perhaps we have become too clever for our own good and too remote from the things that really matter. Blogs, whether we write them or read them or both, are a way of telling us that we're part of the action. We're going somewhere. We're on the train.