Why The Hard Problem is a conundrum

Olivia Vinall as Hilary in The Hard Problem. Image by Johan Persson

Tom Stoppard's new play premiered at The National Theatre last week.  It was in every sense a big occasion: this is Stoppard's first new play for nine years and the last to be directed by Nicholas Hytner during his triumphant 12-year term as the theatre's artistic director.
Anticipation ran ridiculously high.  Then the play started.  
In a typically Stoppardian move we enter on what might be a love scene between a teacher and his pupil; only it isn't romance they are discussing. Or at least only incidentally. Instead they are locked in argument about the nature of consciousness - the hard problem of the title. Is it purely a physical mechanism, something produced by the hot wiring of the brain, or does it spring from something and somewhere different?
The entire play continues to explore this question.  Hilary (Olivia Vinall), its appealing protagonist, is a psychologist who wants to believe there is more to life than the mechanistic workings of biology and chemistry,  Unfashionably, she prays to God, hoping for miracles - a course of action prompted by her sense of guilt and sorrow about something that happened 13 years before.  It is her longing that propels the play - and you feel it is Stoppard's desire too, a reluctance to assent to science as the only source of answers.
Even more than most Stoppard, the play is full of long speeches of explication. It covers an extraordinary amount of ground: not just the question of consciousness, but philosophical arguments about the nature of altruism, the workings of the financial markets, and the likelihood of coincidence.
 Despite Hytner's elegant direction, Bob Crowley's clever set which suggests the electronic pulses of brain activity, and some good performances - notably from Vinall and Lucy Robinson - while I was watching it, I felt engrossed, but slightly disappointed. It seemed to fail to spring into full and engaging life. 
Yet on the bus home, I found I was thinking about it, slotting its pieces into my mind. In these days that have followed, it has stayed with me, making me ponder the questions it raised.
 I realised how its action is actually a laboratory model of its argument - how the uncharacteristic altruism of the billionaire financier Jerry Kroll (brilliant Anthony Calf, shouting into a mobile in many languages) is not a failure of plotting but an example of the unpredictability of human behaviour; how Hilary's actions are an embodiment of the love which her cynical tutor reduces to the need of the species to maximise gene survival. .
This sense of the richness of the piece, its thought-provoking subtlety doesn't alter my experience of watching it. But it does make me value it more.
At his best, Stoppard can both entertain and challenge, simultaneously making his audience feel smart and reducing them to laughter.  
The Hard Problem never does that.  Sometimes, indeed, it makes you feel rather stupid as you struggle to follow its arguments.
For that reason, I don't think it can be counted as the playwright at his very best. Yet it is vital and stimulating, resonant in a way that many more obviously enjoyable plays are not.  Having seen it, my world view and interest has been changed.  That in itself is a definition of terrific theatre.