Paul Mason tells us that we should have more social mobility. Hmm, OK, but the problem is that he's misunderstood what it was that actually happened. This was not the cause of that great shift in the 1950s and 60s: 

My father lived through the thing that terrified Richard Hoggart, in The Uses of Literacy, and then Eric Hobsbawm: the decline of the implicitly brutal and subliterate “proletarian way of life”. Watch a movie such as Saturday Night and Sunday Morning or This Sporting Life to understand the yearning for improvement, non-brutality, tenderness and advancement that gripped working-class people in the 1950s.

This, in turn, had material roots: cheap rents, free education, aggressively interventionist social work against dysfunctional families, TV stations run by philanthropists rather than, as now, people determined to promoting ignorance.

If I wanted to save capitalism, I would tell Theresa May to implement all this urgently – and more.

No, really, that's not what happened. We agree entirely that this was not unusual:

I know this kind of social mobility is possible because I am a product of it. My paternal line on Ancestry.co.uk reads: hatmaker, hatmaker, hatmaker, miner, miner, economics editor of Newsnight.

The paternal line of a lot of us is very similar. It is of this writer for example even if shifted by a generation.

What did actually happen is something that even Polly Toynbee occasionally manages to get right. The British class system is not purely economic - everyone should know that. Further, there's a very strong tone in it of manual labour being working class, indoor work no heavy lifting being middle class of one sort or another. So, what is it that happened over the decades of that burst in social mobility?

We moved from a society in which a goodly percentage of the population, 30, 40, perhaps 50% dependent upon date, did manual labour to one where some 10% do now. The percentage of the population engaged in agriculture fell at the same time, near everyone works in some form of services these days. That's that indoor work no heavy lifting which our class system defines as middle class of some form or other. We're not going to have a similar movement again in the future as there just isn't that portion of the population to move out of manufacturing and manual labour.

It's worth noting that Mason is one of those who complains bitterly about the fact that we've no longer got all those manufacturing jobs. Exactly the change which caused, not just allowed, the social mobility he's celebrating. After all, if 50% of the people still need to report to a production line each day then we're not going to have a great deal of that class mobility away from working class jobs, are we?

 But by far the most embarrassing point we can make about Mason's argument is that he's not grasped something which even Polly Toynbee can.

Really, less perceptive than Polly? It's not a recommendation, is it?