Why do we keep calling for excellence in teaching when there is so little excellence elsewhere in the world? I mean, when did you last call out an excellent plumber? Does your doctor give excellent consultations? And which of us, in our private lives, can claim to be an excellent parent? Partner? Friend?
Excellence in teaching is so rare that when you come across it, it knocks your socks off. The first time I saw it, I was collecting three seven-year-olds from school to take them swimming. The classroom door stayed closed five, then ten minutes after the school bell had rung, and the corridor seethed with mothers and minders muttering about cars on double yellow lines. Then the door burst open and all thoughts of parking tickets were blown away as the children flew out radiant with the excitement of learning.
It seems - because all the way to the pool the boys could talk of nothing else - that when you light a candle and put a glass beaker over it the flame eventually goes out! Because there's no more oxygen in the air!! And that's because flames need oxygen to burn!! Did I know that? Well, yes - no, but did you ever know it properly - with a beaker and everything.
I never met this magical tutor because he was a supply teacher, and the next day he had vanished, but I knew his reputation and think it no coincidence that he was someone who had given up full-time teaching two years before, and retreated to a small-holding in Wales, from which he only emerged when the pleas of his former headteacher grew too desperate to bear. Excellence is a hard taskmaster, and burn-out a serious hazard.
Good, on the other hand, is more sustainable, and not nearly so rare in the classroom, although it can be harder for parents to spot, particularly as our children grow older and more secretive about school life. ("How was your day?" "OK.") There are, of course, tests and reports and parent-teacher evenings, but when I asked a dozen parents how they knew when their children were being well taught not one of them mentioned these. Instead their answers were surprisingly physical. Well-taught children, it seems, are literally bright-eyed and bushy-tailed. They're awake, energetic, up and dressed and ready for school; they seem to find more to do, they're willing to have a go, and less likely to fly off the handle.
For me, the key is their degree of openness to the world. The writer Adam Mars-Jones says that when he is working on a short story that works, things seem to fly up out of daily life and clamp themselves to it like filings to a magnet, and that has always seemed the perfect metaphor for the well-taught child.
It is, if you like, the Blue Peter principle - a litmus test that can be applied to all children as they come from school on winter evenings with their hand already extended towards the television button.
The poorly taught child will sit slumped in front of Blue Peter, glazed and lethargic, images sliding over the eyes without any apparent connection to the grey matter beneath. The medium-well-taught child will slump in a slightly more alert way and, if asked what on earth Tim is doing up that termite hill, will know, and may even stir long enough to tell you. The well-taught child on the other hand, slumps in an entirely different way, soaking up what's happening and interacting with it, commenting, making connections and framing questions. The mental motor might be on idle, but you can still tell it's had a good outing and is firing smoothly on all cylinders.
Which is not to say that what is good teaching for one child will be good for them all. Mine have followed each other through school like jars on a conveyor belt, and been filled with quite different things by the self-same teachers. One of my daughter's best teachers was a bright young thing fresh out of training college with a chatty disposition and unjaded enthusiasm for school life. This "big sister" model was such an inspiration that my daughter worked like a slave to win her approval, but to my son she was just another nice-ish teacher who "doesn't half go on".
His best teacher was a straight-backed, straight-talking New Yorker who ruled her classroom with the iron rod, and a ban on all sloppy language, particularly the word "Yo!". This woman was no paragon - she was embroiled in a law suit over a piece of chalk she had flung at a child - but to my son, who was being bullied all the time, and whose work was faltering, her cocktail of fairness, respect and praise was exactly what was needed to set him back on his feet.
I recently combed through a year's worth of The TES's My Best Teacher interviews for clues as to what made a good teacher. I was struck by how vividly people remember their teachers' physical presence; how much a warm voice or encouraging smile can mean to an impressionable child. Kindness figured large, as did attention to detail. It was clear how often revered teachers are iconoclasts, impatient with rules, following their subject for the love of it and sweeping pupils along in its path.
But mainly I felt deprived. Never, I thought self-pityingly, had I ever had a single teacher like these. Mine had all been second-rate, plummeting to abysmal at Cambridge (supposed centre of excellence) where my tutors had been either dried-up old land scientists in the ante-room to retirement, or distracted geomorphologist mothers, juggling a baby with one hand while struggling to find a reference on glacial erosion with the other.
Yet something else becomes clear from reading My Best Teacher, and that is that the best teachers in the world can only do their stuff when pupils are ready to receive what they can give. Teaching is an unstable chemical equation, and if you're an unrewarding student - too proud to ask for help, too shy to debate, too unfocused to see what's on offer - then excellent teaching will never be yours.
So perhaps we should stop calling, so unrealistically, for excellent teachers, and settle for the merely good. And perhaps we parents need to think more clearly about what we can do to make our children good pupils. Which is not to say meek, line-toeing ones, but ones whose minds are open, whose sights are set high, and who understand that what they get out of their school day will always be, to some extent, a function of what they put in.