But the sad fact is that marriages are still going to break up. Not all relationships can be held together. So I want to focus on the 1.7 million people who are single parents, bringing up nearly three million children.
We cannot just wash our hands of them, and say that it is a great pity that they ever got into that position. After all, most of them did not choose to become single parents. Six out of 10 have been married, and are either bereaved, or divorced or separated. Only one in seven single parents has never been married or lived with their child's father.
It is tough enough being a parent in a two-parent family. It is far tougher trying to bring up a child on one's own. And it is more responsible to do that than just to walk away.
No one can be proud of the fact that Britain has the highest proportion of lone parents in the European Union. We must support marriage. But we also need effective policies for people who are single parents, despite everyone's best efforts. There is no point just unconstructively nagging at people after they have become single parents, without doing enough to help.
That is why we need a fresh Conservative approach. The key question is: what is the right balance between the tough and responsible unpaid work of looking after the child, and breadwinning paid work to escape being dependent on benefit?
The evidence is that, especially when children are very young, there are advantages for them in having a parent staying at home and looking after them. But when the children get older the position is reversed, especially for daughters.
For sons brought up in a two-parent family, there is a 50 per cent chance of their achieving an advanced educational qualification, regardless of whether their mother worked or did not work during their teens. And if they are brought up by a lone parent they have a 29 per cent chance of getting an advanced qualification if their mother worked during their teens, and a 30 per cent chance if their mother did not work.
If a daughter is brought up in a two-parent family, her chance of getting an advanced educational qualification is 38 per cent, whether the mother worked or not. But a daughter brought up by a lone parent has an appallingly low chance - only 7 per cent - of getting a qualification if her lone parent does not work while the daughter is in her teens. The chance goes up to 24 per cent for the daughter of a lone parent who is working.
Of course, part of the effect is due to the boost in income. But just the experience of seeing your parent out at work, making her way in the world, can raise the aspirations of a teenage daughter. Would any of us want our child to be brought up in a household where, throughout most of their childhood, there was never any experience of a parent going out to work? Of course not.
I propose that our party's policy should be that single parents should be expected to be actively seeking work when their children are of secondary- school age. They should no longer receive income support unconditionally, simply by virtue of not having an income and being a single parent. They should instead be expected in return to be actively seeking work. The policy needs to be backed up with practical measures and implemented carefully.
Ultimately, however, claimants need to know that this is not a bluff. The trouble with the Government's approach is that all the bureaucracy, the interviews, and the casework advisers have far less effect than you would believe from the hype.
Single parents need assistance and advice and support. But they also have to know that, as their children become older, they will be expected to be actively seeking work - a policy that is in the interests of the child, the parent, and society as a whole. It is common sense for everyone.