There was, in my national school, a teacher who I'm sure has many counterparts in schools across the State. He was the passionate after-hours sports coach, Gaelic sports of course, a man for whom the classroom seemed like a mere base camp for the ascent to real education out beyond on the field.

There was a unity and a totality to his life with education and sport. When pacing up and down the sideline at a match, his leg used to kick a phantom ball, just as an 11-year-old struggled with the real heavy leather.

This total, unconscious identification with the game did not descend, fortunately, into the absurdly disproportionate vehemence that you see sometimes in men coaching junior sports.

One doesn't expect the teacher on the sideline, the spectator in the crowd or the writer in the commentary box to run out onto the field and start to play. But in the realm of business and public policy observation, where youthfulness and physical fitness matter little, the leg occasionally does twitch when the ball is about to be kicked out on the field. It is not at all unknown for the erstwhile detached observer to throw caution to the wind and have a crack at playing. And this is what I am doing now.

Since I am taking up a job as special adviser to the Tanaiste, Mary Harney, on strategic policy issues, I find myself remembering the image of the teacher of years ago.

Should observers and commentators kick the air, let alone the real ball? Some think they should suppress the urge to declare where they stand on issues for the sake of impartiality. Or should they campaign and wage war? Reportage and commentary are different.

To my mind, it is a very artificial notion that one can forever analyse issues without recommending anything, implicitly or explicitly. And once one recommends, one is already influencing and playing. An American at the Wall Street Journal once said to me, "We don't want rolling analysis - we want a clear hypothesis, strongly argued".

Another editor told me of the American journalistic tradition of the "nutgraf", the point of the story or the analysis that should be stated in one sentence at the top of a piece. Be upfront, clear and open about what you are saying.

The starting nutgraf is a rare bird in opinion writing in Ireland and Britain. This piece bears that out. Sometimes, it can be a bit too rigid, not allowing for our faltering literary pretences.

I like the challenge of being clear and open about what one is saying, arguing to a conclusion which, if accepted, would have consequences. This is to be consequential rather than inconsequential.

In the realm of public policy it is to be political. You could say that any commentator or any publication that was not self-consciously political was inevitably inconsequential. I don't mean necessarily party political in the sense of always promoting one team alone, but political nonetheless.

In a democracy, everyone's opinion counts, although all strands of one's opinions are telescoped into a blunt instrument, the vote. Some of us are more fortunate - if one desires such things - to find ourselves invited on to soapboxes or to be given loudhailers.

It helps greatly, as in my case, when the soapbox is the robust podium of a premium media outlet like this newspaper, rather than a battered old shoebox. One of the great things about this, which I shall miss, is the feedback by e-mail. It is especially gratifying to hear from people who hardly ever agree, but read nonetheless.

Some of the areas that have generated most response have been liberalising immigration and fighting xenophobic attitudes; the real arguments for tax cuts; the need to move beyond the "Celtic Tiger"; how to measure and address poverty; the need to get the State out of areas of commercial life where it had no useful role; and how Ireland should situate itself in relation to US and European cultures.

To work as an adviser to the Tanaiste with an invitation to give views unambiguously, to put the nutgraf upfront, is to carry on in a different, less visible, way. It was said of US presidential aides that "they should be possessed of high competence, great physical vigour and a passion for anonymity". Others will judge the first, I can work at the second, and the third leads to a change on this page. Unlike Scott of the Antarctic I may be gone for a while, but I hope to return.