Of course, when I were a lad there was no such thing as differentiation. The secondary in my home town only went as far as the fourth year, so in a standing-room only bus, I was conveyed to nearby Lanark each morning for my post-primary education, having shown Higher potential at age 11. By definition, any Carluke yins at Lanark Grammar were brainy, so we went automatically into the top stream.

But here’s the clever bit. Rather than stigmatise kids by placing bright children in classes with names like 1A and less able pupils in 1Z, all the classes were named after trees. The top trees were ash, bay, elm, fir and oak - short names. Next came teak and pine, with maple and willow for “remedial” children. Note how the least able had the hardest-to-spell class names. In the second year things got a bit more complicated. Ash and bay became the top classes (short names near the beginning of the alphabet). Pupils in these groups took German rather than techie if male or German rather than undifferentiated soup-making if female. Enlightened or what?

The system - which probably gave the English language the phrase “out of your tree” - is no longer in use. Rampant deforestation occurred many, many years ago, though there are still staff who remember the terror of the teaks, the misery of the maples and the sound of leather against willow. Classes have mundane letter-of-the-alphabet names and are set for some non-practical subjects. Everybody gets a shot at techie and hame eekies. Doubtless, having mixed-ability classes, staff of these departments employ some form of differentiation. We all do (don’t we?), even if it is only at what a colleague calls the “pantomime dame” level, directing particular content at appropriate parts of our audience.

For a time it was the fashion to boo-hiss whole-class teaching. Individualised learning was the way ahead. I have seen resource-based learning work extremely well, but the physics department that employed it always stopped the pupils every so often to stand up before them and tease out, develop and lay clear some new piece of theory.

You have to do this and it is sheer folly to undervalue the role of the teacher in both presenting a difficult concept and evaluating the degree to which it has been understood. Whether everybody should be doing the same thing the rest of the time is another matter.

The average class is a curious soup containing the thick vegetables, the game, the noodles and those content to be the laughing stock. But unlike soup, you can get pea and ham from a chicken when an individual pupil matures or suddenly develops an understanding of a subject. In the days of the tree classes there were occasional transfers from teak to fir but most people remained where they were.

If streaming becomes the norm again I will suggest that, in honour of the unknown PT who gave Wilson the opening quote, we name them things like oxtail, minestrone, leek and so on. Then we’ll put them all together and make the Scotch broth that has served us so well so long as there have been people willing to stand over it adding seasoning at the right time.

Gregor Steele was never out of his tree but has been in the soup.