By Janadas Devan, Review Editor

'He who can, does. He who cannot, teaches.'

That has to be among the silliest things that George Bernard Shaw ever wrote. He didn't originate the jibe - its usual form goes 'Those who can, do; those who can't, teach' - but he certainly contributed to its wide dissemination.

The truth of the matter is that teaching entails as much 'doing' as any other profession; indeed, it probably demands more from a person than most other jobs.

Consider how few exceptional teachers most of us have had in the course of our educational careers. Most of us would have had at least 12 years of schooling and some would have had an additional four years of university. In the course of those years, each of us would have been lectured, tutored or supervised by at least 100, if not more, teachers. Many, if not most, of them would have been competent; some would have been good. But how many would have been truly exceptional?

I can name only three among the 150 or so teachers I have been taught by over the course of my own educational career: My Primary 6 teacher, Mrs Ernest Lau at Anglo-Chinese School; Professor Koh Tai Ann at the University of Singapore; and the Shakespearean Prof Scott McMillan at Cornell University. I was fortunate to have had many more good teachers, some of them distinguished scholars, but these three stood out qua teachers.

I have come across many more exceptional doctors, though I'm certain I have been treated by far fewer than 150 doctors in my life. I have had personal contact with many more exceptional public ser-vants, lawyers, corporate executives, scholars, journalists - even plumbers.

Truly exceptional teachers, at whatever level - primary or secondary school, undergraduate or post-graduate - are rarer than exceptional doctors or lawyers. That is so not because the profession is filled with people who cannot 'do'. On the contrary, it is so because teaching - exceptional teaching - involves a rare order of doing.

You cannot convey values by just reciting them. An exceptional teacher conveys them by example, by osmosis almost, from every fibre of her being, even in her speech and gesture - like the late Mrs Lau.

You cannot teach a method of analysis merely by detailing its procedure. An exceptional teacher reveals the power of a method, an approach or a discipline, by herself becoming its instrument - like Prof Koh.

You cannot convey a love for a subject by insisting mechanically on its attributes. An exceptional teacher communicates through the sincerity of his interests, the genuineness of his enthusiasms, the disinterestedness of his scholarship - like the late Prof McMillan.

Bad teachers insist; good teachers show; exceptional teachers are. The reason the last are rare is that the most important things in any subject, as in life, cannot be taught explicitly. They can only be embodied as examples - in the teachers themselves.

Take, for instance, writing: How does one teach good writing? I conducted a column writing course for some journalists recently and had to grapple with this question.

One can go through lists of the things one should or should not do in writing. Every primer on writing provides such lists. Strunk and White's Elements Of Style, for instance, has a list of 21 'suggestions and cautionary hints', from 'Place yourself in the background' and 'Write with nouns and verbs' to 'Avoid fancy words' and 'Do not take shortcuts at the cost of clarity'. Such lists are useful - as far as they go.

Most bad writing is the result of writers not having thought through what they want to say. So they proceed by flinging a mass of words in the general vicinity of their vaguely apprehended intended meaning, in the hope of somehow hitting the target. Lists of dos and don'ts can help writers to be more conscious of their writing. Like the advice to take a deep breath when you are tempted to do something hasty in anger, lists can slow you down, force you to take stock. A competent teacher can, by using such lists, encourage students to be self-reflective.

A better way would be to show what constitutes good writing. There is no good writer who is not also a good - and extensive - reader. That being so, just reading examples of exceptionally good writing and analysing why they are good can do a world of wonders.

'These are the times that try men's souls' - just eight short words, forming a simple declarative sentence, as Strunk and White note. What if Thomas Paine had written instead 'Times like these try men's souls' or 'How trying it is to live in these times!' - or, heaven forbid, 'Soulwise, these are trying times'? Each is a grammatical sentence but none carries the distinctive signature the original does, even more than 200 years later. Why is that so?

Yes, a competent teacher of writing can convey a great deal of information about good writing by telling, by showing, by analysing, even by admonishing. But at the heart of good writing, there is a mystery that cannot be conveyed by instruction.

'The great enemy of clear language is insincerity. When there is a gap between one's real and one's declared aims, one turns as it were instinctively to long words and exhausted idioms, like a cuttlefish squirting out ink.'

George Orwell wrote that in his famous Politics And The English Language, an essay I used in my recent course on writing. I realised that was the heart of the essay, the distillation of Orwell's wisdom on the subject - and I did not have a clue as to how I might convey its tremendous truth: 'The great enemy of clear writing is insincerity.' Only someone as sincere as Orwell, I finally realised, only someone who exemplifies such sincerity in his own writing, can teach sincerity.

Those who can, do; those who are, teach - without intending to do so.

This article was first published in The Straits Times.