When Thatcher first become PM her political allegiance was, of course, to Conservatism. The only other ‘-ism’ to which she subscribed was ‘monetarism’ - the doctrine that inflation is caused by printing money and can be cured by restricting the money supply. Monetarists argued that, in the interests of efficiency, taxation should be kept low, state-controlled industry should be privatised, and free market forces be allowed to operate.

Such right-wing economic thinking was a major factor in Thatcherism but was not its essence. Thatcher did not originate these ideas, and nor was she the first British politician to put them forward. Furthermore, her Chancellors were often keener monetarists and tax cutters than she. She privatised a swathe of British industry, beginning with British Telecom in 1984, but such a policy had its precedents and she cautiously exempted the railways. Similarly, she sold council houses to their tenants but was not the first PM to adopt this policy and nor did she pursue it with the gusto of some of her ministers.

‘Economics is the method’, she insisted in 1981; ‘the object is to change the soul.’ By rolling back the frontiers of the State - which stifled individual initiative - she believed that the genius of the British people would flourish. Hence, her governments attempted to cut back on welfare spending and refused to prop up ailing industries for the sake of avoiding unemployment. It was not governments which caused unemployment, insisted Thatcherites, it was the trade unions, whose demands for higher wages priced their members out of jobs. Thatcher defeated the long miners’ strike of 1984-85 and, in successive Acts of Parliament, curbed the power of the unions.

‘I can't bear Britain in decline, I just can’t’, Thatcher had insisted in 1979. Her aim was not just to reverse economic decline but to boost Britain’s stature in the world. Her chance came in 1982, with the Falklands war - a turning point in the construction of Thatcherism. Thereafter, she flamboyantly combated the centralising tendencies of the European Union (‘no, no, no’) and, alongside President Reagan, was a fierce critic of communism.

She also achieved a high degree of personal dominance in Britain. She even began to use the ‘royal we’ (‘We are a grandmother’). Now she took on the miners. Now she took on the consensus-seeking ‘wets’ in her own cabinet - and was not above lambasting her own loyal colleagues, including the long-suffering Geoffrey Howe (‘more and more like a blancmange’). She was effectively ‘packaged’ for the media as the ‘Iron Lady’. Thatcherism became synonymous with confrontation.

‘What a superb creature she is, right and beautiful!’ gushed the poet Philip Larkin. Her great virtue, he said, ‘is saying that two and two make four, which is as unpopular nowadays as it has always been’. To her detractors, however, she was adopting a presidential style and destroying cabinet government - so that, essentially, Thatcherism meant the cult of the leader.

It seems clear that Thatcherism was not an ideology. Its ideas were neither original nor consistent. John Campbell has recently identified Thatcherism’s main contradiction: she ‘celebrated a culture of rampant materialism … fundamentally at odds with her own values which were essentially conservative’.

But were Thatcher’s policies particularly significant for Britain? ‘I came into office with one deliberate intent: to change Britain from a dependent to a self-reliant society.’ Did she do it? What overall effect did she have on the welfare state? Did she produce an economic miracle, a vigorous ‘enterprise economy’? What of British culture? Did deregulation - for instance, with the Broadcasting Act of 1990, which pleased her most ardent admirer, the media tycoon Rupert Murdoch - provide greater consumer choice only at the cost of debasing standards? And what of Britain’s position in the world? Did this latter-day Britannia really put the Great back in Britain?

On the answers to such questions will ‘Thatcherism’ stand or fall. At the moment, we probably lack the sense of perspective to judge fairly. Will Mrs Thatcher be admired by future historians? Or will Thatcherism be seen as no more than a rhetorical spasm of indignation at Britain’s irreversible relative decline? If the latter, Thatcherism may be considered little more than the bombastic style of one remarkable but deluded woman and a concoction got up by the media to help sell tabloid newspapers, the political equivalent of a page three nude.