In his autobiography, The Words (1964), Jean-Paul Sartre described his discovery of cinema as a child. He would have been 10 years old in 1915 when The Birth of a Nation opened. But he hardly noticed particular films at first. What he saw or felt was something he called "the frenzy on the wall". That could have been a reaction to the brilliant battle scenes in Griffith's films, but it also covers the still face of Garbo absorbing romantic loss, or the stoic blankness of Buster Keaton baffled by the physical chaos around him. The frenzy was in the whirl with which projected film ran at 16 or 24 frames a second, a passage of time that seethed on the wall – and, paradoxically, the serenity of another reality. That was the inherent madness and the magic in cinema: that we watch the battle but never risk hurt, and spy on Garbo without having her notice us.
At first, the magic was overwhelming: in 1895, the first audiences for the Lumière brothers' films feared that an approaching steam engine was going to come out of the screen and hit them. That gullibility passed off like morning mist, though observing the shower in Psycho (1960) we still seem to feel the impact of the knife. That scene is very frightening, but we know we're not supposed to get up and rescue Janet Leigh. In a similar way, we can watch the surreal imagery of the devastation at Fukushima, or wherever, and whisper to ourselves that it's terrible and tragic, but not happening to us.
How large a step is it from that denial of our full selfhood to the wry passivity with which we observe global warming, economic collapse and a new freelance nuclear age as portents of an end to a world that is beyond us? Pioneers of film, such as D W Griffith, Chaplin and Abel Gance, hoped that the movie would make a single population in the world angry or moved enough to share liberty and opportunity and end war and intolerance. But perhaps it has made for a society of voyeurs who associate their own hiding in the dark with the safe futility of dealing with the screen's frenzy. So the world is chaotic and nearing ruin, but not for us – not yet. And so we talk of democracy still in a scheme that is intent on us purchasing anything and overlooking everything else.
The book I have just written, The Big Screen, is an attempt to deal with this condition. For decades, we told ourselves we were watching film and its illusion of reality. And so we treated movies as if they were theatre or novels given this extra investment and the kicker of sensation – of being there. The first measuring stick of the system was what made the most money. That's how The Birth of a Nation was the birth of a business. Though the president at the time, Woodrow Wilson, is supposed to have said, "It is like writing history with lightning", which is in the category of things you still read in movie ads or the exhortations of film professors trying to make the young believe that the best movies are akin to Dickens, Henry James or Proust.
Confession: I've done my own share in that attempt. As writer and teacher I have tried to say this film and that one are really good (and good for you), and why. It's a modest attempt at education and it leads to such things as the recent Sight & Sound poll on the 10 best films ever made (and I voted in that election). But this new book reflects a way of thinking that says it doesn't matter too much which films are good and which are bad. They are all frenzies on the wall. What is most important is the fact of the screen as something that separates us from reality. All along, I think, we have been watching screens, and it is only recently, with the profusion of electronic screens, some so small that people aged over 25 can't quite see them, that this has been appreciated.
Once you've identified the primacy of the screen you begin to see that all films are more alike than they are different. They resemble guns and nuclear weapons. In America, where there are so many guns, the defenders of the right to own them say: don't blame the guns, just blame the maddies and the baddies who get hold of them. But maybe the gun pushed too many people into those categories by its very existence. It alters our relationship with reality and diminishes our need for reason and language. Can it be an accident that guns are one of the chief props in the screen's frenzy?
As for the nuclear weapons, the only country in the world that has ever dropped such bombs rages against the threat of Iran obtaining them because there are "fanatics" in Iran, and people whose insecurities may make them recklessly trigger-happy.
Once you grasp the numbing power of screens at that level, it's clearer I think that the claims for film as an art or a business are close to fallacies. Now, I am too old to stop making those claims, or to give up the belief that A is better than B. (I think Rear Window is better than the new champion, Vertigo, but I didn't put either of them in my top 10.) Such ranking systems have furnished jobs for everyone from Andrew Sarris to Gilbert Adair (to name two movie writers lost in the past year). It has built an informed audience – yourselves – that may even purchase The Big Screen to keep me alive a little longer.
But I fear film studies, film in academia and good criticism of the medium are all McGuffins compared with the dislocating stealth of the screen. People in the street nowadays bump into one another because they are intent on screens, which means they hardly notice the architecture, the acts of mayhem and indifference going on around them, or the weather. The medium that was alleged to bring all realities to our laps may have reduced us to laptops.
Of course, I ignore my own regret in The Big Screen. I go on at some length about "great" films from an age in which people believed there could be great films – let's say 1915 to 1975. And since then? Well, I think, now, anything goes if it serves the screen and keeps us in alleged entertainment and information, as our true state moves ever further from being entertaining. Should screens be banned then? Nice try. Technology never goes back in the bottle – not screens or guns, not bombs or digitisation. As politics gives up, so we wait for some Google or other to reinstate fascism and explain our helplessness.
'The Big Screen: The Story of the Movies and What They Did to Us' by David Thomson is published on 11 October by Allen Lane