World Book Day coincided this year with the release of two surveys, one showing that fewer than half the parents in the UK read to their children daily, and another revealing that household spending on digital entertainment had for the first time surpassed that on the printed word. One reaction might be wonder that it took so long; these figures might seem pretty optimistic to anyone who cares about literacy. But then there is the news that Northampton county council, bleeding to death from cuts in central government funding, is to close 21 libraries and open another 21 for only one day a week. That is not just a retreat from any ambition of universal provision but a panicked rout. It could take decades to recover the ground abandoned.

The collapse of public libraries turns reading into a matter of class distinction. Those children whose parents read to them will enjoy, in every sense, huge advantages over those who do not. Reading books is not just a matter of the technical skill of turning marks on paper into words in the mind. Schools can and do teach that, albeit perhaps a little later, and albeit with varying success. But that skill really is only the beginning.

True readers play with words, just as words play with them. Reading to small children is at first purely joyful and then, when the child has discovered a favourite story, increasingly exasperating as the same words must be repeated like a charm, but it is never wasted. In the plain sense of the words it is a labour of love. Familiarity with language, the ability to construct worlds, and later to deconstruct them, and the ability to recognise, follow and ultimately to build and sustain complex arguments are all skills that enrich our apprehension of the world and help us to master it. This is what reading gives children, and what they are robbed of when libraries close and parents are too busy, tired, or even indifferent to read to them.

The best children’s books provide a scaffolding for the growing soul. They show us bravery and wonder, and dangers overcome. To read them out loud makes a bridge between childhood and adulthood, between reader and read-to, so that the parent reading can recover for a moment the sight of the world through a child’s unfilmed eyes. It may be the most sublime form of play that has ever been invented.

Readers don’t have to be parents, of course. One of the largely unnoticed accomplishments of the BBC at the moment is the series of five-minute bedtime stories read by unlikely celebrities on CBeebies. Actors such as Tom Hardy and Patrick Stewart can be found taking a break from saving the world or destroying it for the rather more important work of reading out picture books without special effects beyond the illustrations. It’s a great service to parents who have no time or energy left over at the end of a working day, and it can help to prevent reading aloud from shrivelling into a middle-class habit. That would rob poor families of future horizons and present joys.