Of course, our society hasn't given up on the idea of regulation in all areas. We don't have unrestricted freedom in the drugs industry because we feel that the wrong kind of drugs can very badly damage your health. But we do have a freedom in ideas, because we don't in the end believe that very much is at stake. We could quite easily watch a lifetime of dubious television while remaining entirely sane and healthy people. If we're reading dross, so be it.

It always comes as a surprise, therefore, to read Plato on this topic, for what marks out the Greek philosopher is his extraordinary belief that the wrong kind of ideas can ruin your life. Watch bad plays, listen to silly music, read cynical books and your soul will be corrupted. This is the thrust of Socrates' famous defence of cultural censorship in The Republic. "The voicing of these [corrupt views] is sacrilege, they do us no good," says Socrates. "We must oversee the work of story writers, accepting any good stories they write and rejecting all the others." Socrates argues that just as we wouldn't allow a nurse to tell corrupt stories to children, so in the ideal state, we must take extreme care with what people are able to hear and see.

I'm starting to have a little more time for Socrates on this topic. Would it not be wise to reconsider the impact of cultural deregulation and return to some of the safeguards which once gave us the high quality of public culture that is now sorely lacking? In broadcasting, the BBC could without too much difficulty be retooled so that it focused only on disseminating what Matthew Arnold famously called "the best that has been thought and said in the world" (Jonathan Ross and Russell Brand would go to ITV), while Channel 4 could with little cost to the taxpayer and a few adjustments to its charter be returned to its former glories. Meanwhile in publishing, the Net Book Agreement could be put back in place along with a German-style mechanism of regulated bookselling, which has produced not only the finest bookshops but also the most commercially robust publishing houses in the world.

Such moves would of course involve a reduction in liberty of one kind - but as has often been pointed out, you can't have all liberties at once. You can't have both the freedom to generate maximal income and the freedom to enjoy decent culture. The financial crisis has taught us that the promotion of one kind of liberty always involves the restriction of another.