September is the time of year when aspiring new teachers drag themselves out of their undergraduate life into the terribly harsh new world of teacher training. All over the country PGCE students are forced to tidy up their act - their clothes, hairstyles, body-piercing and sloppy ways of talking. It’s all got to go.

A professional life beckons as would-be teachers fine-tune their image in advance of their first step into schools. But that’s the easy part. More complicated is the mental preparation, the intellectual readiness, which is required before the new teacher even gets started. That, and a firm grounding in reality.

Trainees often have a very naive understanding of the nature of education.

John, one of our bright young graduates, was a recent example of this.

Around his fourth week of teaching science he was visibly going under.

Frequently on his laptop in a search for ready-made resources, he stopped only briefly to admit to me that this was all far more time-consuming than he had first thought. His lessons didn’t work out the way he had planned them, the pupils didn’t listen in the way that he expected, they gave up easily.

He was lost when I tried to explain some wider issues, such as the impact of low self-esteem on learning and the negative home lives of some of our pupils. And he was certainly too wobbly to begin my usual talk about the role of the teacher in neutralising the harmful aspect of tests and levels, and the challenge of making an often incomprehensible curriculum make sense.

He displayed a remarkable innocence, not at all uncommon in PGCE students.

In short, he was finding every aspect of teaching difficult. A week later he came to the conclusion, the right one, that he was not cut out for the profession. His last words to me as he thanked me for my understanding were: “I’d rather stand in a dole queue than prepare another science lesson.”

Some people might blame the selectors who initially offered a place to John. But I don’t. I have been on the selection panel for PGCE courses. It is a hellishly difficult task spotting someone who has not grasped the full magnitude of the job.

One problem is that many applicants have been “hot housed” in the education system since the age of four and have never actually been out of it. We’d break the law if we told the young hopefuls at interview: “You look promising. Come back in a few years’ time when you’ve lived a life, or two.”

John’s fiendish task of preparing lessons revolved around his inadequate attempts to gather the right materials. He was soon on the stony path to discovery that it’s all those tricky intangibles that are the bedrock of success: motivation, pace, challenge, rapport, behaviour management. And in the wider world, catchment areas, league tables, Ofsted inspections, government policies and initiatives.

The trouble is, they’re all tangled up: you pull at one thread and you end up in a knot. So, how would you ensure that new trainees entered the profession with their eyes wide open? All teacher-training institutions now insist on some kind of school experience for graduates before beginning the course. Essential, but we all know how a highly skilled classroom teacher can make it look easy. Something more is needed.

The very best teachers are usually those who maintain an enquiring mind throughout their professional lives. How would you uncover that particular quality at interview? Perhaps, after the stock question, “Why teach?”, you could follow with “What do you believe are the major impediments to learning in a child’s life?”. Or perhaps even more demanding: “What do you think is the main purpose of schooling?” No right answers, of course, but if a mini-debate ensued, as it surely would, at least you would have some evidence of the candidate’s ability to reflect on major educational issues.

What if you took this a step further by insisting on a pre-interview reading list? What if all applicants knew they had to discuss what they had read? You could ask some cracking questions. For example:

* Can mainstream schooling learn anything relevant from A S Neill’s Summerhill?

* What are the flaws in Ivan Illich’s argument in Deschooling Society?

* Did Ted Wragg have a point in his TES columns when he regularly tore into the national curriculum?

* Can you summarise John Holt’s arguments in How Children Learn?

* Which ideas did you find most exciting in Gordon Dryden and Jeannette Vos’s The Learning Revolution?

Why not put the candidates through intellectual hoops? Why not ensure that they have at least thought about the education system they are hoping to join? Intellectual calibre? Moral fibre? Social and political awareness? We want it all in the teaching profession.

New teachers, almost without exception, come into the job wanting to “make a difference” to the quality of young people’s lives. I personally wouldn’t let them in without that shiny ideal, and it is the role of ongoing trainers to keep it polished and intact. This is much easier to do if the groundwork has been done and the mind is already rich with ideas, and fired up by the fascinating and hugely complex nature of schooling. As for the pre-interview reading list, suggestions on a postcard please.

Lindy Barclay is assistant headteacher at Redbridge community school, Southampton