Paul Vallely: Shakespeare gets top billing, but we ignore the rest of the cast

English is shot through with the Bard's words and phrases, but what of his harder plays, and the work of his successors?

All-seeing Eye: A man thought to be Shakespeare, at 39. His birth and death are marked tomorrow (Art Gallery of Ontario/AP)

What will you do to celebrate Shakespeare's birthday tomorrow? Me neither. Despite the best efforts of the BBC, whose Bardic offerings have gone into overdrive, with big-gun historians such as Simon Schama, James Shapiro and Neil MacGregor on how the great globalisation of the Elizabethan era first put a girdle about the earth, marking 23 April is more honoured in the breach than the observance.

Perhaps it's no coincidence that the great man's birthday is memorialised on St George's Day. (It's not known when he was really born, though he was baptised on 25 April 1564.) The modern English sensibility is embarrassed by notions of the nationhood of this blessed plot, so the day of our patron saint, like our national scribe, is best passed over quietly. The Celts of Scotland, Wales and Ireland can exalt in their special days, and ethnic minorities may celebrate their cultures. But all things English are best minimised for fear of triumphalism or cultural superiority – patriotism being the last refuge of the English scoundrel (Dr Johnson, not the man from Stratford).

There will, of course, be the usual touristical pride, pomp and circumstance in Stratford-upon-Avon, to observe the 448th birthday of the local glover's son made good. But, in the main, the event will be feted in far-off places. A World Shakespeare Festival this week will perform all 37 of his plays across the globe in nearly 50 languages, including the midsummer madness of a Bollywood version of Twelfth Night. If Shakespeare is our contemporary, as the Polish critic Jan Kott once claimed, with his universal human preoccupations of love, death, power, jealousy, ambition and greed, that appears to be acknowledged elsewhere more than in his native land.

All around us there is the sound of our literary heritage slipping away in the long, melancholy susurration of a withdrawing ebb tide. When a survey last month showed that only half of today's children knew the Lord's Prayer, cultural commentators lamented that this meant they wouldn't be able to understand Shakespeare, Tennyson or T S Eliot. Fat chance that many of today's kids can be dragged away from their PS3s to become rapt in secret studies of poetry as difficult as that anyway.

I sat up in my armchair some weeks back when I heard a cop in a mid-evening TV police drama announce: "Why, this is hell, nor am I out of it." This is Mephistopheles's great line from Dr Faustus. But there it was, deracinated, torn from its context like the "Best of" operatic arias that the great musicologist Sir Donald Tovey once scathingly described as "bleeding chunks".

Marlowe is splendidly memorable in chunks, such as his Tamburlaine's "Is it not passing brave to be a king, And ride in triumph through Persepolis?", or that most famous of Elizabethan lyrics, "Come live with me and be my love, And we will all the pleasures prove". But audiences have for years been cheated of the long, spine-chilling, rhapsodic passages of the last act of Faustus in which the bold doctor tortures himself with the prospect of a repentance he cannot embrace. I have not seen that in the theatre for 30 years.

The same could be said of Shakespeare's less fashionable plays, which languish while companies around the country all vie with one another for yet another gimmicky production of The Comedy of Errors. There are honourable exceptions to that: Edward Hall's magnificently physical all-male company, Propeller; Declan Donnellan's inventive and intimate Cheek by Jowl; and the direct humanity of Barrie Rutter's Northern Broadsides, which is currently touring an immensely funny yet profoundly moving Love's Labour's Lost. But why no recent Coriolanus, Troilus and Cressida, Richard II or Antony and Cleopatra?

And what about the other now rapidly being forgotten 16th- and 17th-century literary geniuses? In the theatre, we do not see much of that other great Jacobean revenge dramatist, John Webster, who, T S Eliot said, "saw the skull beneath the skin", and observed in The White Devil that we think caged birds sing when, indeed, they cry. My spellchecker tried to change The Duchess of Malfi into the Duchess of Mali. An African production; interesting.

The metaphysical poets Donne, Herbert, Crashaw, Vaughan, Traherne and the rest are out of fashion, with their combination of intellectual conceit, vibrant metaphor, sexually charged passion and profound religious fervour. Yet an English Puritan such as Andrew Marvell was able both to chide the irony of quaint virginity and perceive the human soul in a teardrop of dew, long before a Romantic like William Blake saw eternity in a grain of sand. What of Bunyan, Milton, glorious Dryden?

What we have left of them, to turn to a Titanic metaphor, are little icebergs that have broken off from the cultural mass and are floating by, like fragments of forgotten meaning in an ocean of postmodern meaninglessness. Untune that string, and, hark, what discord follows. What country, friends, is this? It is that of those who have been at a great feast of languages and stolen the scraps. It is a world living off its cultural inheritance but showing little concern for how it is to be replenished.

Maybe I am too gloomy. My 12-year-old son came home from school the other day with Chaucer in the original. I thought he might struggle. But it was, to him, another language, like French or ancient Greek. Children are built for learning. Mandarin is a difficult language for Western adults, but millions of Chinese toddlers seem to manage. Perhaps our failing is that we fear exposing our children to challenging things.

We have become too used to Philip Larkin's infamous pronouncement on what our parents do to us. We would be better off with Adrian Mitchell's glorious parody: "They tuck you up, your Mum and Dad...". The words of Mercury are harsh after the songs of Apollo.