Like it or not, teachers are still expected to be suitable role models for their students. This presents something of a problem, because although some teachers go to great lengths to disguise the fact, they are obviously no less wicked than the rest of humanity.
So, just as doctors are required to take the Hippocratic oath before they can practise, I propose that teachers should be obliged to swear their own Hypocritical oath: "I will beseech my charges to do as I say, not as I do."
This might seem too cynical. Isn't teaching, after all, a vocation in which those who answer the calling must meet higher moral standards than those who don't? It is certainly true that being in loco parentis brings with it special responsibilities. But when the vices of teachers do not directly interfere with their ability to exercise their duty of care, they cannot reasonably be the concern of parents and employers.
Teachers already do society a great service in stressful jobs which have less status and pay than many other graduate professions. To demand that they are also more morally pure than the rest of us is a demand too far.
However, there are pragmatic reasons why teachers are wise not to flaunt their imperfections. Kids have an uncanny ability to spot the weaknesses in their teachers and exploit them ruthlessly.
And rumours spread and mutate in the playground with vicious rapidity. If, at morning registration, Miss Jones is observed to have had a heavy night, by the final bell she is a certified alcoholic.
Authority is also easily undermined if you are exposed as a wrongdoer. How can you reprimand someone for anything other than the most serious breach of school rules if they know you've been stealing pencils?
It must be every teacher's nightmare to be confronted by lippy kids saying, "You can talk", and knowing that they are right. Teachers who are not seen to be leading by example will find their charges lose whatever respect for authority they still have.
Also, we want schools to encourage children to aspire to high standards of conduct. We know that human beings constantly fail to be as good as they should. But it is better to set the bar high and fail from time to time than it is to set it low and sanction everyday wrongdoing.
For these reasons, it is important that teachers appear to be, if not whiter than white, then at least upholders of the values we aspire to. But how do we square this with the realistic recognition that they often fall short?
The unavoidable answer is toleration of hypocrisy, pure and simple. We cannot demand unimpeachable ethics from teachers, but neither can we afford to be too open about their failings.
All we can ask is that teachers stand for high standards of ethics and do not allow their message to be undermined by revealing how they themselves fail to meet them.
That does not mean teachers themselves should necessarily be happy with this double standard. Those who don't want to be hypocrites should try to live by the standards they teach. But the concern of employers, students and parents should be only with how teachers behave in public.
Julian Baggini is the author of What's It All About? Philosophy and the meaning of Life (Granta).
WHAT KIND OF ROLE MODEL ARE YOU?
What is your teaching persona? What example do you set? We've devised a completely scientific questionnaire to help you find out.
1. What is your preferred method of restoring order to a restless class?
a I silently fix the class with my steely gaze.
b I ask the kids why they are restless and when I discover it's because they are alienated from their labour by the authoritarian regime, I lead them on a protest march to the head's office.
c My charges never dare to show their restlessness.
d I wish I had one.
2. What are the chances of one of your students spotting you staggering out of a pub drunk?
a Very low - even when I'm mildly tipsy I carry myself with dignity.
b Since we often get drunk together, very high.
c I should punish you merely for suggesting the possibility.
d Every time, mate, every time.
3. You stub your toe and, in front of some students, swear. What happens next?
a I apologise with such understated sincerity that they accept it and the matter is never discussed again.
b They laugh and tell me to be more f***kin' careful.
c I immediately confess to the headmaster and ask to be chastised, preferably physically.
d The students swear at me constantly for the rest of the year and if I try to stop them, they simply remind me of the incident, using words of one syllable.
4. When students hand in homework to you, when do they expect to get it back, marked?
a When it is ready.
b They don't. Marking is undertaken by the class collective according to non-hierarchical and egalitarian criteria.
c At the beginning of the next class, of course.
d Since they never hand any in, I have no idea.
5. You've organised a school trip. How will you spend the day?
a Inconspicuously overseeing the students, smiling at the ones I see.
b Hanging with the kids at Alton Towers, telling rude jokes about the head.
c In the stalls, in full sight of the children in the gods, making sure they're applying what I taught them about Wagner's Ring cycle.
d Probably at the police station, explaining how a group from my party ended up shoplifting from Harrods when they were supposed to be at the Tower of London.
6. You fall in love with a teaching colleague. How do your students react?
a We were both touched by the enormous card and bouquet they made for our wedding.
b They ask cheeky questions about our sex life, which I answer using balloon animals for clarity and humour.
c Love? A colleague? I don't understand.
d By chanting "Slag and Slaphead in a tree, B-O-N-K-I-N-G."
7. What is the most valuable thing you've ever pinched from the supplies cupboard?
a I once took a Bic biro when my own pen ran out of ink. I replaced it though.
b The keys, which I had cut for the kids.
c I guard the cupboard far too well for anyone to ever steal any thing from it.
d The first time I tried to lift a ring-binder I was caught. I've never dared try again since.
8. What do your students know about your personal views on politics and religion?
a Nothing, except that I'm not an extremist.
b Everything. Teacher neutrality is a myth used to covertly sustain the dominant power inherent in the status quo.
c All they need to know is that, as far as they are concerned, I am both their God and ruler.
d According to them, all they know about my views is that they are "stupid".
9. How do you tend to get on with parents when you meet them?
a We have warm and polite discussions in which the interest of the student are at the heart.
b I gently chastise them for their failings as parents, which their kids have told me about.
c It's not my job to "get on with them". I simply tell them the brutal truth about their brats.
d Communication is usually conducted through lawyers.
10. What's the worst thing you've ever done which your students have found out about?
a I once stubbed my toe and cursed the class hamster.
b I once tried to oppress them by misusing my power and telling them what to do.
c Ten years ago I added up a student's exam marks incorrectly, awarding her 67.5% instead of 67%. It still haunts me in the small hours.
d A high court injunction prevents me talking about it.
How did you rate?
Mostly As: You are a veritable Mr Chips. Your dignity and quiet authority earns you the respect and admiration of your students and peers, and appearances in "my best teacher" columns. You are a paragon worthy of emulation. We suspect you don't actually exist.
You see yourself as a hip, street-wise version of Dead Poet's Society's John Keating, inspiring youth to be themselves in this mad, conformist world. In reality, the kids are probably laughing at you, not with you, and will end up complaining that you didn't teach them properly and help them get well-paid jobs or university places.
Mostly Cs: Gradgrind lives. Some students will learn to appreciate that your harsh discipline got them through subjects they struggled with. Most will simply hate you and feel embittered for life. Not that you'll care.
Mostly Ds: You have all the authority of a chihuahua in a pack of delinquent dobermans. The students walk all over you and not even your colleagues can blame them. The only lesson you have taught them is a cautionary one about how the weak are dumped on. You might consider a career change. Starbucks are hiring, I hear.