The Oxford English Dictionary's definition of "progressive" is, as you might expect, relatively pithy.

As an adjective it describes the proportion of tax paid increasing relative to the sum earned, while as a noun it can denote an "advocate of social reform". What the OED doesn't delve into, however, is its contemporary political usage, where it can pretty much mean anything you want.

Like the term "social democracy", since the mid-1990s the word "progressive" has been so thoroughly debased it's become virtually meaningless. Last week, I watched the First Minister propagate this degradation with another speech in which he set "progressive" Scotland against a "regressive" rUK, or more specifically the Coalition Government.

Alex Salmond's speech (organised by the "progressive" journal the New Statesman) was essentially a reheated version of his 2012 Hugo Young memorial lecture, only this time round an independent Scotland was depicted as a "Northern Light" rather than a "progressive beacon", redressing the influence of the "dark star" otherwise known as London. In essence, to those of a progressive bent, independence was presented as an opportunity rather than a threat.

It was a nice line - though hardly original - and had the added benefit of being pitched to an audience inclined to take it at face value, for there is a section of the London-based liberal-left commentariat willing to believe that in the SNP and independence many of their cherished aims have found a new - and electorally successful - outlet.

In a recent column, for example, The Guardian's Jonathan Freedland concluded "Scotland wants no part" of the UK's rightward drift, while last week he fleshed out this thesis in the New York Review of Books in an essay which included the astonishing observation "Scotland has only a few private schools". I'm not sure which Scotland Mr Freedland has been visiting, but there are "a few" independent schools in Aberdeen alone.

The trouble is the considerable gap between the progressive rhetoric of the Scottish Government and its actual policy tends not to get noticed in London, even now that Fleet Street (as was) is paying much closer attention to what's happening north of the Border. To many such observers - with honourable exceptions - if it walks and talks like a progressive, then it must be one.

To be fair to the hosts of last week's New Statesmen lecture, they were careful to highlight the decidedly non-progressive aspects of the First Minister's agenda. When editor Jason Cowley raised the proposed Corporation Tax cut, Mr Salmond said his intention was not "to make people rich", but rather "resist the gravitational pull of London". Wouldn't this, pointed out a woman from Caithness, simply make Edinburgh the "dark star" of an independent Scotland?

Similarly, when blogger George Eaton asked whether he'd restore the 50p income tax rate, the First Minister murmured something about not wishing to put an independent Scotland "at a tax disadvantage to the rest of the UK". So on taxation alone, and remembering the OED's definition, the SNP's stated intent is anything but "progressive". As with Air Passenger Duty, the plan is actually regressive. Even the Scottish Government's supermarket tax - a rare case of increased taxation - was ditched.

This is a point many "progressive" fans of the independence proposition seem to miss, or perhaps subconsciously ignore: while Mr Salmond objects to London's dominance of the UK (and rightly so), he doesn't fundamentally object to the basis of its wealth. And while he sees independence as a means of checking the "dark star", he plans to do so by undercutting it, not via any fundamentally different economic approach.

A close reading of the White Paper reveals a thoroughly orthodox take on the political economy of an independent Scotland: a "competitive" tax environment (ie cuts) will fuel growth, the proceeds from which will be skimmed off to pay for a slightly more generous welfare state.

In this context, the First Minister is about as progressive as Tony Blair, who with the benefit of a booming economy was at least able to make good on that "third way". That it proved unsustainable makes the SNP's attachment to such orthodoxies all the more curious; if, as certain London-based commentators appear to believe, independence is all about rejecting neoliberalism, then doing so based on a neoliberal prospectus is a very curious way of going about it.

Such intellectual contortions are also hallmarks of other so-called "progressive" policies, not least a council tax freeze (currently pulling apart Cosla) that deprives councils of cash to fund frontline services which disproportionately benefit the worst off and a tuition-fee policy which has been less effective at getting poorer kids into university than the frequently caricatured English system.

That said, depictions of the SNP as "Tartan Tories", a charge revived by Johann Lamont last week, go too far. In truth, the record of both the UK and Scottish Governments is mixed when it comes to "progressive" policies: Westminster, for example, has gradually lifted the low-paid out of paying income tax, led the way (at significant political cost) on gay marriage and maintained one of the world's highest levels of international aid.

Which brings me to that other self-styled "progressive", Ed Miliband. He plans to use his Scottish Labour conference speech later this month to argue a UK with him as Prime Minister wouldn't need Scotland as a "progressive beacon" or "Northern Light". Committed, as he now is, to restoring the 50p tax rate and not cutting Corporation Tax, Labour clearly intends to chip away at the SNP's progressive credentials.

The First Minister, of course, usually gets round this by focusing on Mr Miliband's willingness to tilt towards a decidedly unprogressive agenda on welfare and immigration. That, of course, would be a reasonable line of attack if it weren't also hypocritical: whatever New Labour's drift to the right, Mr Salmond's own ideological journey from Marxist Nationalist to Laffer Curve devo-maximalist leaves Mr Blair looking relatively consistent.

At least Mr Miliband, for all his faults, has produced a critique of the post-2008 economic landscape, while even the neocon Michael Gove has provoked a much-needed debate about public school dominance of UK public life, both subjects on which the Scottish Government has little (if anything) to say.

As James Maxwell, another New Statesman blogger, put it: "Miliband has displayed a willingness to confront 'vested interests' generally lacking in the Scottish First Minister."

Mr Salmond reflected last week he hoped, whatever the outcome, the referendum would leave Scotland a more "progressive" place, an edifying if quixotic thought. To paraphrase Peter Mandelson, we're all, it seems, progressives now.