Imagine someone were to say that Tory incompetence and mendacity were a major threat to Britain's position in the world, and that the Suez crisis proves just this. You'd think them mad: that debacle has no relevance to today's politics.

However, according to Matthew Parris in the Times, many Tories have such out-dated attitudes to unions. He says they believe they benefit from Labour's "indefensible" links with unions:

They know the toxic potency in millions of minds of the image of the raised fist of organized labour. With relief they sink into the comforting upholstery of a ready-made rhetoric about trade union barons, winters of discontent, beer and sandwiches and No 10, union militants...

For millions of voters, though, the winter of discontent is as distant from their lives as the Suez crisis is to mine. There'll be voters at the next election whose parents weren't born in the winter of discontent. And many first-time voters in the 1979 election are now retired.

What's more, it's perfectly arguable that our problem today is not overly powerful unions, but overly weak ones. Stronger collective bargaining which causes a shift from profits to wages might well be a good macroeconomic strategy.And even conservatives should support unions because they are an example of Burke's little platoons and a healthy alternative to state regulation.

In this light, it's no surprise that the public is not especially hostile to unions.

Which poses the question. Why, then, do Tories like the "comforting upholstery" of anti-union rhetoric?

One possibility is the false consensus effect; we tend to exaggerate the extent to which others share our beliefs.

Another (not exclusive) possibility is that beliefs can be path-dependent; we believe things because we used to, and continue to do so even after such beliefs have lost truth-value or utility. What's more, I suspect this path-dependency can sometimes be transmitted from generation to generation. So, for example ethinic minorities are very unlikely to vote Tory, in part because of memory of the party's racist past; Greeks dodge taxes because of the legacy of Ottoman rule; and Germans are hostile to inflationary policies because of memories of Weimar hyper-inflation. Perhaps Tory antipathy to unions falls into this class of beliefs - a form of folk memory that is no longer useful. We are all prisoners of history.