It is usually a mistake to start by presenting pupils with examples of what you want them to avoid. The wrong ideas presented at the beginning of a lesson often have more impact than those that follow.
However, I'm going to break my own advice to highlight dangerous habits of thought that are part of the conventional thinking of teacher trainers, and which students are apt to absorb without realising. These habits of thought are ubiquitous; I call them "intellectual vices". If you want to be a good educator, be aware of them and do all you can to oppose them.
Vice No 1: Values
This is the nonsense you read in conservative and radical propaganda on the teaching of "values". Whether it is traditional values of deference to authorities, radical nostrums about building democratic classrooms, or even the government's obsession with "citizenship", these "values" are not the business of education.
Starting teachers may be obliged to teach such things but this is not your real work. That is to enable pupils to participate, in what Matthew Arnold called "a disinterested endeavour to learn and propagate the best that is known and thought in the world". In other words, the only value that you, new teachers, are concerned with is knowledge. Now there is a word that's debased, so let me emphasise: subject knowledge is the only value that matters.
Vice No 2: Philistinism
I vividly remember a conference at which I heard three professors of education arguing that the distinction between higher and other forms of education was that academics recognised that they knew nothing. Far from being a model of Socratic scepticism, these "know-nothing" academics expressed a general cynicism about knowledge that is quite common.
At a more mundane level, philistinism appears as just being uninterested in knowledge. Take history. The historian Eric Hobsbawm has described young people today as living in a sort of "permanent present". With no knowledge of the past, they cannot understand the present or have any sense of a different future.
Philistinism is spreading: eventually, this will be the sorry state of pupils in every class. It takes different forms; the elevation of personal experience over objective knowledge is everywhere.
Ditto the cynical attitude towards research or statistics. These philistinisms can be combated: reassert the joy that comes from knowledge and understanding. It might sound like a cliche but it is not: your major post-millennial challenge is to seek to inspire pupils with the love of knowledge.
Vice No 3: Opining - close relation to Philistinism
"Everyone is entitled to his or her own opinion" is a commonplace assertion. But opinions in this sense are unimportant, uninteresting and often merely expressions of ignorance. The methodology you are taught on teacher training - buzz groups, brainstorming, sharing experiences, etc - encourages opining. You are encouraged to transfer these approaches to your own teaching. Opining has many expressions: "making a criticism" or "speaking your mind" is not differentiated from "giving an opinion". Getting pupils to distinguish for themselves the difference between giving an opinion and making a critical comment based on knowledge is an important start. Opining is now more prevalent because it appears to be a democratic and unthreatening approach to any topic. Reassert the distinction between knowledge and opining and place yourselves in the true authority that your subject knowledge gives you.
Vice No 4: Relativism
The most prevalent of all of these dangerous habits of thought. For example, one of my colleagues expressed his wariness about suggesting that Shakespeare was a better writer than, say, JK Rowling. This was something he found "difficult", after all, everyone loves Harry Potter.
Too often relativism takes refuge in a supposed sensitivity to other people's views and values. It's hard for new teachers to reject such sentimentality as it seems "judgmental".
Rubbish. Education is primarily a training in just such judgments.
What used to be called the "hidden curriculum" exists in contemporary teacher training in the uncontroversial, uncontested and unchallenged propagation of the related intellectual vices of value pluralism, Philistinism, opining and relativism.
I hope you have a love for your subject. If starting teachers do not, we run the risk of future generations of children taught intellectual foolishness. A love of your subject means introducing them to the best that is known and thought in the world.
Dr Dennis Hayes is head of post-compulsory education at Canterbury Christ Church University College and the author of 'Defending Higher Education: the crisis of confidence in the pursuit of knowledge' (Kogan Page, to be published in February next year)