Long ago, when there was a flourishing coal industry, there was a small contest in the anthracite area of Carmarthenshire, involving two trade unionists. I remember discussing their chances with an old miner, who were likewise old lags.
One of them had been active in the St John's Ambulance and in the local rugby team and had contributed to the life of the neighbourhood. The other - let us call him Dai Thomas - was of more reclusive, even scholarly habits, and had studied J W F Hegel and Karl Marx, though for lighter reading he preferred Jack London and Prince Kropotkin. Clearly, he was the man for the job.
"You see," my friend explained, 'Dai has got the dialectic.'"
It was, I suppose, another way of saying he had the gift of the gab. Dr John Reid has it too. It was one of the first things I noticed about him. It was in the Silver Age of Annie's Bar, after the exuberant years when Jim Callaghan had nightly danced on a wraith-like majority, and before the long, slow descent into universal dullness.
It was in the intermediate stage, when Margaret Thatcher had possessed a huge majority and Dr Reid had just entered the House as MP for Motherwell. I have also some recollection of him lurking on the premises as Neil Kinnock's man-of-business in Parliament, but I cannot be absolutely sure of that.
He was certainly in position by the bar in 1987. I got on well with him and quite looked forward to our encounters, for "encounter" suggests an element of combativeness which has been present throughout his life. By this stage he had exchanged - or, at any rate, supplemented - Hegel and Marx with Gramsci, who were clearly so distinguished that they did not need a christian name.
Somebody else who could be so referred to was Stalin. Dr Reid stayed loyal to Stalin for longer than most of his contemporaries. On one occasion a member of the dictator's admiring audience faltered in his applause and actually stopped clapping, whereupon the unfortunate chap was taken out and promptly shot. Those officials at the Home Office could learn a thing or two from Dr Reid.
Many is the companionable glass that I have shared with him, but we have gone our separate ways. In particular, he has signed the pledge. As the old Band of Hope song goes:
My drink is water bright
From the crystal stream.
Or, perhaps more movingly still:
Lips that touch liquor
Shall never touch mine.
Dr Reid's background in the Party has served him in good stead. Thus the party line will change, often quite suddenly. Instead of the line changing, the Central Committee will, however, require re-education: rather as the Home Office will require it, or, for that matter, the entire Government up to and including Mr Tony Blair, for even the great leader himself is in need for re-education.
We can take a homelier analogy. I owe it to Mr Nick Robinson in the Daily Politics programme on Wednesday. I like to pay tribute to my fellow practitioners in the field whenever possible. Dr Reid, as Mr Robinson described it, was in Sybil Fawlty Mode. "Oh I know," she would say, "I know". There was nothing to be done. The Russian Front is partly to blame, with Stalin and his Scorched Earth policy.
But what is Mr Blair to do? Or, which is slightly different, what is to be done with Mr Blair? Only a year has elapsed since the general election. Mr Blair said as much at Prime Minister's Questions last week. It was about the only amusing - or it was the only self-confident - remark he had made during the entire session. He said that Mr David Cameron, or Mr Cameron's party, had lost the election, and Labour had won it. The Labour backbenchers scarcely bothered to raise their heads from the enshrouding gloom.
Mr Cameron's backing line-up had, by contrast, a whole chorus of cheeky lads and even lasses. They were not - and are not - a pretty sight. Mr Speaker Martin had to call the boys and girls to order. The Prime Minister had to call for the protection of the Chair. It was, of course, the Speaker who was to do the calling rather than Mr Blair.
He was perfectly competent to look after his own interests, few more so. Indeed, Mr Speaker seemed to me to be emphasising Mr Blair's weakness than to be allowing Mr Blair to resolve matters in his own way, as he would have been wholly capable of doing.
But then, that mysterious commodity, authority, has a habit of slipping through the fork like ice-cream that has been left too long out in the sun. John Major had to endure five years of talking behind hands, even though he was not a wholly bad Prime Minister; Margaret Thatcher was effectively off her head for her last year or two; while Harold Macmillan used the pretext of an operation to resign as he wanted to do in any event. It was written of Bishop Joseph Butler, the great moral philosopher of the early 18th century: "The late Dr Butler['s] ... custom was, when at Bristol, to walk for hours in his garden, in the darkest night which the time of the year could afford, and I had frequently the honour to attend him. After walking some time he would stop suddenly and ask the question: 'What security is there against the insanity of individuals?'"
The loss of authority can take several forms. If once lost, it can rarely if ever be recovered. The misfortune - if it is a misfortune - which has overtaken the Government is that two of its pre-ponderant politicians have gone on to the downward slope.
Mr Blair has been at it too long. But Mr Gordon Brown has had to wait for too long, as Anthony Eden had to wait for too long before being allowed the succession by Winston Churchill in 1955. In the same year, C R Attlee waited for too long for Herbert Morrison (almost certainly, deliberately so). It was Hugh Gaitskell rather than Morrison who was ready to succeed him.
Mr Brown is even more formidable than Morrison. But Dr Reid is formidable too in his own way. He has made himself invaluable. The old Stalinist has also made himself enemies: perhaps this time it will be Dr Reid to be shot. For such is this rough old world of politics.