All of which leads to brow-furrowingly puzzled groups of blokes standing around a grotty old Land Rover and an pound;840,000, 1,000 horsepower, 260 mph, 0-60 in 2.5 seconds Bugatti and concluding that they are both of equal quality. Hard, isn't it?
If you're a chief inspector, you're supposed to have a firm grasp of all this. Broad-browed, clear-eyed and wise, you survey the world and just know what's good and what's better. I'm bound to say that it helps if you've spent your life in art schools. The opportunity they give daily to contemplate the pile of bricks in the corner and the confection of barbed wire and broken glass threatening life and limb in the corridor, and to analyse publicly and convincingly the aesthetic merits of each, gives you the practice you need for inspecting.
What helps even more, how-ever, is to have sat at the feet of a Master. I have been fortunate enough to experience recurrent bouts of Socrates-gazing. My first object was an art master at school. He also taught fencing and his method of imparting the subtleties of good drawing was to welt you round the side of the head with a sabre (stiff and heavy), while you tried vainly to defend yourself with an epee (frail and floppy).
But the post-doctoral course on quality recognition was delivered by the rector of the Royal College of Art at which I then worked. He, too, had more than a touch of impatience, which had earned him the soubriquet among all who knew him of "piranha teeth". This reputation for moments of unbridled rage had been amassed since he was very small, in a life cushioned by inherited wealth. It was adorned with periodic crescendos, including the occasion when, as publishing director of a national newspaper, he had been kept waiting by a secretary chatting on the phone to her boyfriend. He had sought the most effective means of attracting her attention. He did it by hurling her filing cabinet through a window on to the street below. Job done.
I should perhaps say "allegedly" here, because a tangle of real and probably apocryphal stories appeared to entwine themselves round his life like ivy round a broad oak. Indeed I once went into his room to find him bawling out a reporter from the Evening Standard for daring to suggest that tales of his hasty temper might be exaggerated. "I've spent my life building that reputation and it saves me a lot of trouble!" went the refrain.
Below this daunting surface lay a deep vein of kindness. But his real virtue was an unerring eye for quality. He demanded that everything - not just some things or most things, I do mean everything - should be faultless. And I do not mean "good" or "very good". I mean faultless. This can be hard to live with. If he arrived at the glass door of the college one morning and found some student had left fingermarks on it, he would not enter. He would stand outside shouting until an attendant rushed out to polish the glass.
New students were greeted with the message that they were the best 350 art and design graduates in the world (they were); that nothing would be spared to help them become the best postgraduates (I don't dare tell you how much was spent on each one); and that staff who failed to match up to them would be dismissed (they were, too, and on the spot).
The moral of this tale is uncomfortable. It is that if you have never experienced quality, do not revel in it every minute of every day, as you are unlikely to know what it is and to promote it effectively in others.
This argument is perilously close to the old chestnuts about elitism and connoisseurship. It can be distorted to suggest that only a Lorenzo dei Medici can foster a Michelangelo; only the privileged have a wide experience of quality.
Let's get down to basics. If you have never been well-taught, the chances are that you will have no real depth of understanding of good teaching.
More controversially, because learning is fundamental to good living, it is unlikely that you will be able to detect good learning if you haven't lived life to the full.
When you see inspectors enjoying a sybaritic moment, that's what they're doing: boosting their understanding of quality. An ounce of experience is worth a peck of theory.
David Sherlock is chief inspector of the Adult Learning Inspectorate