Her senior colleagues in her own party - Keith Joseph and Nicholas Ridley, for example - were more important thinkers than she was and had done much to prepare the ground before 1979.
And Friedrich Hayek was probably the most important single contributor to the acceptance of the doctrine that - as Ronald Reagan was proclaiming in the US at the same time - "government is not the solution to the problem - government is the problem."
Where Thatcher came into her own is that her very limitations as a thinker made it easy for her to drive through the programme that others had devised for her.
She was not assailed by the doubts that might have given pause to a more thoughtful person.
Her strength was the simple force of her personality that allowed her to dominate a male Cabinet - best exemplified by a Spitting Image skit of the time when Thatcher and her Cabinet were dining in a restaurant and the waiter asked the Thatcher puppet what she wanted. "I'll have the steak", she said. "And the vegetables?" the waiter inquired. "They'll have the steak as well," Thatcher replied.
Whether the ideas were hers or not, her supporters will maintain that their implementation made a huge difference - and a difference for the better.
Even today, they will argue that her tenure as Prime Minister heralded a national revival and reversed what was becoming a national decline.
Sadly, these romantic notions have no foundation.
Her espousal of monetarism, her removal of exchange controls, her disregard of manufacturing industry, and (despite her antipathy to the idea) her inability to resist and reverse British membership of what became the EU, all intensified and hastened the decline of British manufacturing and left the country ill-equipped to face an uncertain future.
On the wider world canvas, her contribution was equally negative. Her collaboration with Ronald Reagan (hardly an intellectual giant) helped to convince onlookers that neo-liberalism was the way of the future and that it could not, and should not, be resisted.
Their joint decision to remove exchange controls was a major step - indeed, the major step - towards a global economy - one in which global corporations no longer needed to pay heed to elected governments, but could get what they wanted by simply threatening to move their investments elsewhere, to regimes that offered lower costs, and rules and regulations that were less effective to protect local workers.
In New Zealand, Rogernomics and the "mother of all Budgets" were the direct progeny of those Thatcherite certainties - their distant echo still influences our politics today and inhibits the ambitions of reforming governments.
Even as a standard-bearer for feminism, she was a disappointment, She espoused what RH Tawney called "the tadpole" philosophy; when she finally made it to the lily pad as a frog, after all the other tadpoles had fallen victim to predation, she croaked "There's nothing wrong with this system - I made it!"
Yes, we should mark and understand the significance of the 40-year anniversary - but whether it was something to be celebrated is much more open to question.
Bryan Gould is a former British MP and Waikato University vice-chancellor
