For that reason alone, everyone from Lillian Hellman to John Wells and Jonathan Miller by way of Dorothy Parker and Stephen Sondheim (and plenty more) has tried to turn this extravagant but famously intractable musical dramatisation of Voltaire into viable theatre.
A significant body of opinion believes that the show is best realised on disc.
Thus we can only applaud the spirit of endeavour behind the decision to try to come up with a new theatrical solution to the problem in the shape of yet another version, this time for the National Theatre, with a "new" book, written and directed by John Caird, assisted by Trevor Nunn.
Bernstein recorded his score with a heavy-duty operatic cast and the London Symphony Orchestra, so when the National's thin-sounding 14-piece band strikes up the famous overture your spirits sink. Musically, matters improve significantly but even at the start there's a bonus in the dominating presence of Simon Russell Beale as the narrator, Voltaire. Caught in the spotlight in the centre of the vast, bare Olivier stage, he beadily eyeballs the entire audience with invincible imperiousness.
Voltaire now has a larger slice of the action, guiding you through Candide's labyrinthine physical and philosophical journey from naive optimism to true enlightenment, and whenever Russell Beale is in charge you feel unusually connected to the action. But even the strength of this new thread cannot bind the show together into a satisfying whole.
John Napier's spare designs - little more than a cunningly deployed set of packing cases - throw the focus on to the actors. The National's ensemble company uses Nicholas Nickleby-style storytelling techniques to whip up different atmospheres in locations across Europe, from drowning at sea to a grand ball in Venice, with gusts of smoke to enhance Paul Pyant's lighting.
Beverley Klein brings the house down as the ill-used Old Lady. She grabs her big scene where she lists suffering every indignity known to womankind - she's been left with one buttock (don't ask) - with tremendously engaging zest, before going one further by launching into a splendidly assured and terrifically funny rendition of "I Am Easily Assimilated". Similarly, Simon Day's ludicrously tall and pompous Maximilian seizes his comedy with delicious aplomb.
Yet the musical and dramatic power of these performances - and that of Denis Quilley as Martin, who refuses to believe in the goodness of mankind - also highlights the fundamental weakness. Not for nothing is this known as Bernstein's Candide. Good acting is not enough. The overall feeling generated is that of a very long story with an outstanding, but separate, score. The approach is typified by Daniel Evans as a nicely boyish Candide.
His sweet voice is simply too light to carry the emotional intensity of the music. Similarly, Peter Darling's choreography is often imaginative but you keep wishing it would lift the temperature to another level to drive the musical motor.
All the stops are pulled out for the hair-raising choral finale, but by then it's too late. Caird's version is more faithful to Voltaire's ideas and has impressive clarity, but the plodding rhythm of his production means that it fails to take fire. Ultimately, it's caught between stools. In terms of music and its dramatic sincerity, Candide is now a chamber piece. But stranded in the Olivier the drama deflates. It would make for economic madness, but I wonder what it would be like in the Cottesloe?
In rep, National Theatre (0171-452 3000)