Leading article: Mr Cameron's responsibility is to give us some detail

It would be easy to characterise David Cameron's speech to the Demos think tank yesterday as the Conservative equivalent of the kind sometimes made by American politicians in homage to motherhood and apple pie. After all, who isn't in favour of "strong and secure families, confident and able parents"? Which political party opposes "an ethic of responsibility from a young age"?

But to dismiss Mr Cameron's words as political boilerplate would be to miss the point, not to mention the serious challenges the Conservatives are setting themselves. In his speech Mr Cameron claims to be shifting from a previous Tory worldview, in which all that is needed as far as social policy is concerned is freedom for individuals and a strong rule of law; or in Thomas Carlyle's phrase "anarchy plus the constable".

It is encouraging that the Tories are grappling with social problems that they previously ignored, or to which they only used to propose criminal justice solutions. It is also hard to deny that Labour's "statism" has stifled civil society in recent years. The ID card programme and the vetting scheme for those who work with children are an indication of a government that simply does not understand the proper boundary between the state and the individual.

But the important question is: how do Mr Cameron's insights translate into policy? His reiteration yesterday of a pledge to bolster the Sure Start childcare programme, and promises to increase the number of health visitors, to introduce Flexible Parental Leave, and encourage relationship counselling make sense, both in terms of supporting families and reducing poverty.

The focus on improving state education through enhancing parent power and the independence of schools is also welcome. So is the shot across the bows of businesses over "the premature sexualisation and excessive commercialisation of our children". This all indicates that the Conservatives do indeed want to address the fraying of the social networks that hold us together, rather than just pretend that the problem can be miraculously solved by stiffer penal sentences for the criminal underclass.

Nevertheless, there are some big holes in Conservative plans. Mr Cameron once again deplored inequality and poverty in his speech. But the immediate effect of some of his policies – a marriage tax break and a rise in the inheritance tax threshold – will be to benefit the comfortably off. This will help widen inequality, not close the gap. Mr Cameron needs to acknowledge this and, if he believes it is a price worth paying for benefits further down the line, explain why.

The Conservative leader challenges Labour's fiscal redistribution model. And its outcomes have, it is true, been less than hoped for. But it is Gordon Brown's tax credits which have kept a lid on poverty over the past decade. Without them, inequality would be still higher. Again, Mr Cameron needs to acknowledge that achievement and explain how he would sustain it if he is truly serious about reducing inequality.

Then there is the fact that social reform does not come cheap. To deal with the deficit Mr Cameron has pledged to cut public spending, rather than raise new taxes. But this raises the question of how he will pay for his new policies designed to "reach out to dysfunctional and disadvantaged local families".

The big idea of Mr Cameron is that greater social cohesion can coexist with a smaller role for the state. It is a beguiling promise. But he still needs to do more to explain how it will be delivered if the public are to be convinced.