Journalists are compelled to read newspapers, rather as you are compelled to prepare lessons. I usually start the day with the Daily Mail. This is partly because the day can then only get better, but also because many of this government's actions would be incomprehensible without an acquaintance with that newspaper's prejudices.
What wearies me is the frenetic air of crisis that the Daily Mail and other papers create. These crises are often generated entirely within the newspaper industry; they bear no relation to the real world.
Take crime. "Crime soars," proclaims the Daily Mail. We have, it says, "a grim toll": muggings up 28 per cent, sex offences up 11 per cent, burglaries up 7 per cent. These figures are based on police reports. You could reduce these figures almost to zero by taking every police officer off the streets. Certain crimes, particularly muggings and assaults, will not be reported if there are no police readily available to receive reports of them.
The British Crime Survey, which asks a sample of people about their actual experience, tells us that crime has been falling since the mid-1990s - by 22 per cent in the case of violent crime. The Daily Mail dismissed the survey results as "a small sample" (that's 33,000 people, which is 32,000 more than most newspaper opinion polls).
Does the Daily Mail matter? The British Crime Survey asks people for their views about crime. About two-thirds think it is rising: readers of tabloid papers are more than 50 per cent more likely than readers of broadsheets to take this view.
Now comprehensive schools. According to some papers, they are always in crisis. Yet the crisis exists entirely in the minds of the London chattering classes. As their children approach the age of 11, they become convinced that we need to restore grammar schools. Their return, we are told, will send standards soaring.
It is apparently beyond these journalists that the proportion gaining A-levels has trebled since grammars were abolished and that if some children go to grammar schools, others must go to secondary moderns. The commentators take it for granted that their own brilliant offspring will overcome the selection hurdles. Only when they argue for secondary moderns - and wax lyrical on how much they crave them for their children - will I take them seriously.
These writers are not fools. They have degrees; they negotiate themselves high wages; they have bought houses in Islington; some have even been teachers. Yet they write rubbish. They have spent the past decade slagging off comprehensives and screaming about rising crime. And all the time, we now learn, the chief executives of multinational companies were fiddling the books and, in effect, taking ordinary people's savings on false pretences. Where were our fearless commentators then?
Yes, I obviously need a holiday. But I will take it with more peace of mind if you will resolve to do one thing when you get back in the autumn. Whatever your subject, please work into your lessons some examples of how newspapers falsify what you know to be true. Remember, most of your pupils will grow up into Daily Mail, Sun and Daily Telegraph readers. the greatest contribution you can make to this country's future political health is to educate them to read the press with as much scepticism as they can muster.
Peter Wilby is editor of the New Statesman