Mal Fletcher gives a balanced overview.

It provided for a tightly administered trading zone, in which partner states could expect to enjoy rich benefits from reduced tariffs and easier access to each other's markets. In the process it opened the doors for political engagement, migration, the exchange of technologies and much more.

Each time I hand my red passport to a travel official in another EU country - the UK not being part of the now-threatened Schengen Agreement - I realise that in my heart I am a Europhile.

Emotionally, I want Europe to work.

Yet my head says, 'hold on a minute; there's an elephant in the room.'

That elephant, though huge and ponderous, can be summed up rather elegantly in just three words: 'ever closer union'. They're short words, but even a small elephant can cast a long shadow.

The idea of a growing unity between its members states is central to the founding documents of the European Union. Sadly, however, the founding fathers - they were mostly men - did not let us in on their secret, the exact meaning of 'ever closer union'.

Does it refer to an increasingly porous trading bloc, with growing opportunities for mobility and for collaboration on pressing problems at home and abroad? (Arguably, of course, collaboration is made easier by digital communications anyway, and these are for the most part not restricted by borders.)

Or does 'ever closer union' refer to a European super-state, a United States of Europe?

I'd be in favour of one of those options, but not the other.

Of course, EU apparatchiks are not normally given to talking about a total political union, at least not in public. Yet their collective decisions often betray a strong desire to centralise and consolidate power at the EU's centres, in Brussels and Strasbourg.

Earlier this week I joined a news debate on the EU referendum on BBC TV. A fellow guest suggested that speaking about ever closer union - at least in its obvious political sense - simply allows the debate to be hijacked by emotion.

Actually, this is not an emotive issue as much as a philosophical one. Everything else hangs on it.

If we reduce the sovereignty of nations within Europe - that is, even further than we may have already done - we move government one huge step further away from the governed. We also remove from the administration and practice of jurisprudence the rich history which nations like Britain bring to it.

Magna Carta was no small thing and British justice has in many respects been a model for much of the free world ever since. This fact often seems to be overlooked by EU plutocrats who seek to override or replace our laws.