Dear Anthony, I found your response to Cameron's speech to the Conservative Party Conference fascinating, but - to me at least - confusing.

You seem to be saying that because Hayek described himself as an Old Whig, and because Thatcher thought she was a Hayekian, she must have been an Old Whig too, which means that the Cameroons must be Thatcherites. The fact is that Hayek, great thinker though he undoubtedly was, patently knew nothing about late-eighteenth century British politics.

The term 'Old Whig' was coined by Edmund Burke during the bitter disputes over the French Revolution that tore apart what was left of the Rockingham Whigs in the 1790s. Charles James Fox, the party leader, was enthusiastically for the French Revolution; Burke was passionately against. Burke called himself an 'old Whig' so as to claim the mantle of the Whigs who had made the British Glorious Revolution in 1688, and who had shaped the revolution settlement. He denigrated Fox and the Foxites as 'new Whigs' to suggest that, so far from standing by the principles of 1688 as they pretended to be doing, they were betraying them.

Hayek, it seems to me, was not a Whig in either sense. He certainly wasn't a Foxite 'new Whig'; patently he would have been against the French Revolution. But I don't think he was a Burkean Old Whig either. He was an individualist, first and last; he believed, not just in a market economy, but in a market society - a highly mobile society of freely-choosing, rationally calculating individuals held together by the exchange relations of the market. Burke would have been horrified by such a vision. He thought society was a compact between the dead, the living and the unborn, in which individual choices were shaped by the supra-rational ties of history and culture.

Similarly, I don't think Thatcher was a Hayekian. She talked like one at times, but she didn't act like one. Hayek wanted a weak state - indeed no state in some of his moods. Thatcher wanted a strong state; and used every ounce of power available to the British state in order to re-make society from the top. In a very real sense, she was closer to Rousseau and the Jacobins - or if you prefer to Lenin and Trotsky - than to either Hayek's ultra-liberalism or Burke's organic whiggism.

I don't think this is at all true of the Cameroons. I think Cameron's 'big society' was - and is - far more than a political ploy. I think he really believes it. He grasped better than any other member of the political class that the statism of the thirty years following Mrs Thatcher's arrival on the steps of no 10 Downing Street was a busted flush: that the British people were tired of Whitehall's incessant hectoring, bullying and frequently counter-productive interventions here, there and everywhere. More important, I think he also grasped that top-down statism against the grain of the culture nearly always fails, and erodes the ties of mutual sympathy which are fundamental to a good society.

I agree, of course, that his Big Society rhetoric was fashioned originally during the boom which has now ended. But so what? I can't see any reason of principle why the Big Society can't be a viable project for government in times of austerity. I know that when times are hard politicians are tempted to reach for the levers of top-down state power: we're going to see a lot of that from the Labour Opposition, I suspect. The real test for the Cameroons, it seems to me, is to resist that temptation. If they do, I suspect they'll be in power for a very long time to come.

Best wishes, David Marquand

PS: It occurs to me that the Cameronian 'Big Society' has a lot in common with the idea of the 'enabling state' that some of us in the SDP tried to develop in the 1980s. Our thought was that the state should enable rather than control; that for the state to enable effectively it would not have to be the swollen, heavy-handed, inevitably clumsy state that had been the favoured instrument of the Wilson-Callaghan Labour Party that we had left in disgust; and that progressives should put much more emphasis on grass-roots reform by civil society than on the state. If you follow that thought through, it is not surprising that the Liberal Democrats (who are, after all, the products of the SDP-Liberal merger at the end of the eighties) should be reasonably content with their Coalition with Cameron. Another implication is that there's no reason at all why the Big Society should be any less compatible with economic austerity than we hoped the enabling state would be.