In those days we lived only a few streets away from Cluny Parish Church, one of those Victorian edifices of which suburban Edinburgh has no shortage.

It was a cold, blowy day for May, but I had met John Smith a handful of times and been charmed each time. The paying of respects didn't feel like an obligation.

I had met the Labour leader and liked him, but had not - or not often - agreed with him. I had liked him most because he had treated disagreements with indulgent good humour, as if they did not, could not, matter much. This turned out to have been a near-universal experience among those who encountered Mr Smith, whether great, good, or journalistic small fry.

But then, he was good with journalists. It might have had something to do with his experiences as a night lawyer, once upon a time, for the Daily Record. It might have been because of an instinct for conviviality. My belief is that he possessed a generosity of spirit, even towards those who might have written something splenetic about certain Scottish lawyers continuing Labour's long procession to the right.

There's still another theory. This one says John Smith had both an intellectual and a moral confidence. Why wouldn't he treat the likes of me with good humour if we were dead wrong? Why wouldn't he tolerate the usual attacks if his Christian socialism armoured him? The coinage would become debased thanks to his successor, but Mr Smith's sense of conviction was hard to miss.

On Monday, 20 years after his last heart attack at the age of 55, a lot of disputable things will be said once again about this lost politician. Often enough, he will be misrepresented. Given what followed for Labour after his passing, at least a couple of tenacious myths are liable to reappear.

On the one side there is the foolish idea that Mr Smith could never have succeeded as well, even electorally, as Tony Blair. There is plenty of evidence opposing that claim, precious little - the last gasps of a "modernising" cult aside - to support it. The public reaction to a fatal heart attack, spontaneous and sincere, is one proof of esteem; the 20%-plus polling lead Labour had established by May 1994 is another.

Against the fiction there looms the fond belief that John Smith was something other than a politician of the traditional Labour right. The myth-making springs, no doubt, from the crushed hopes of the Blair years. The faith that things could have been different runs deep. It's justified, but only up to a point. Mr Smith was not that kind of radical. A devout believer in social justice? Certainly. A socialist? That requires special pleading.

Nevertheless, this is an age of counter-factual histories. The fact that John Smith died in his prime is an invitation to speculation. More to the point is a second fact, documented repeatedly: at the time of his passing the leader had become a source of deep frustration to Mr Blair and that other young moderniser, Gordon Brown, because of his unwillingness to adopt wholesale their plans for new Labour.

Some will tell you Mr Smith was simply cautious by nature (cliches involving Scottish lawyers and old Labour generally follow). Others will point to what was known as "masterly inactivity". With the Tories swamped by sleaze and discredited thanks to 1992's Black Wednesday, it was enough to give them enough rope while Labour prepared for government.

It might be that things were less complicated, but more interesting. Mr Smith was Scottish Labour through and through. He was a cultural nationalist, indeed, when articulating the claim was still allowed. For him, Kirk and politics were intertwined. But there was another factor: in 1994, it was impossible to say that his party had failed electorally in Scotland. What motive was there for "a break with the past"?

In 1992, Labour in Scotland won 49 of the country's 72 seats. Across the UK, Neil Kinnock gained ground on the Tories, but failed to win an election that was supposed to have been his for the taking. You could have argued, as Mr Blair and Mr Brown argued, that profound change was required urgently, that Labour had to disown its history. You could equally have said that the rest of the UK deserved the kind of politics that had served Labour in Scotland. In fact, Mr Smith seemed to say: a bit of both.

"One member, one vote" (up to a point), but no theatrical gestures over clause four. Economic prudence, but no sticking with Tory spending plans for two years in the manner of Mr Brown. Taking business seriously, but no hint that trade unions were allies fit only to be alienated, as Mr Blair believed. Party modernisation attempted as required, but only if those doing the modernising remembered what the party was supposed to stand for.

A Labour government under Mr Smith's leadership would not have enthralled the left. Nevertheless, party, government and country would have enjoyed one large benefit. With Mr Blair busy being tough on things at the Home Office, and with Mr Brown at the Treasury under the eye of a former shadow Chancellor, we would have been spared the fratricidal comedy of the Blair-Brown years. John Smith was that species of "old" Labour leader.

In the game of what-if, those who regret or deplore what became of Labour after 1994, have a trump card. What would Prime Minister Smith have done about Iraq? The squalor into which Mr Blair allowed himself to be led has been well-documented. We don't know, cannot know, how John Smith would have responded to American pressure. But informed guesses are not hard to come by. When attempts were made to explain reactions to his death, the word commonly used was integrity. No-one supposed Mr Smith was always saintly in his politics - "Monklands" is a one-word description - but a belief in his honesty touched colleagues, rivals and the public alike. Allied to this was the perception that here was a pragmatist who tested arguments according to the evidence.

So would he have fallen eagerly for White House hokum? Would this lawyer have ignored his training? For that matter, would he have set Britain's interests aside completely? It has been claimed repeatedly that amid tensions within the Kinnock shadow cabinet the member least inclined to support the first Gulf War was John Smith. The idea that he would have enlisted in the Iraq adventure is not plausible.

Scotland's Parliament is his monument: so much almost goes without saying. His assertion that devolution represents a country's settled (somehow unalterable) will has become central to Scottish Labour's rhetoric amid the campaign against independence. Had Mr Smith lived, he would have led that campaign. But he might also have reminded his party that devolution was intended to be part of a wider reform of the British state.

The past cannot be amended or repaired. John Smith represented an idea of virtue in politics in the days before politicians were mistrusted as a matter of rational habit. We might see his like again, but we have not seen it lately.