DAVID MAMET’S Life in the Theatre lasts 85 minutes, but, unlike some pieces that are aeons longer, it packs three plays into its short, enjoyable span.

One is a Pinteresque story of changing dominance, with an older actor unhappily giving way to a younger one.

Another is an affectionate spoof of drama and what, since the piece’s premiere in 1977, we have come to know and mock as “luvvies”.

And the third is the sort of symbolic piece Mamet presumably had in mind when he said that the actor was “a prime example of the Sisyphean nature of life” and his play “about the attempt to communicate experience and love in the face of and informed by a knowledge of morality”.

I must say I find those remarks pretentious: oddly so, since one of Mamet’s targets is pretension.

You can tell what Joshua Jackson’s young John is thinking when Patrick Stewart, playing the veteran Robert, interrupts his exercises in the gym with “we must not be afraid of process, we must not be clowns whose sole desire is to please, we must not be afraid to grow”. He’s thinking “why don’t you shut up, you boring old fart?” — and eventually he finds the confidence to say “shut up” openly.

The acting in Lindsay Posner’s production is a bit unequal. Stewart displays the subtle, witty skills he learnt in the great days of the RSC and somehow retained during the long years of Star Trek, and not only when he is in the dressing room or backstage, but when he is supposedly onstage, performing extracts from dumb, dopey melodramas.

The trouble is that it is he who is supposed to be in decline and Jackson’s John who is on the ladder to success. You could not tell that from the decent but unremarkable performance given by the actor from TV’s Dawson’s Creek.

Mind you, Robert is the more rewarding part. He must begin by pontificating de haut en bas and end up pleading de bas en haut. He must be grandiose yet insecure, helpful yet envious, jovial yet angry and, when he secretly listens to John’s practice rendition of the Chorus from Henry V, wistful and self-pitying and disappointed to the brink of suicide. With the help of a comical ginger toupee and uncomical puckerings of the face, Stewart manages all that. The play comes in 26 scenes, some as brief as a double-take, which whisk you all over an unnamed but clearly insignificant American rep.

It is, then, very literally a sketchy work. Yet there is human truth and pathos here as well as humour that, yes, sometimes veers too far into caricature. A Chekhov parody is ludicrously wan and a sea rescue far too silly, but when Stewart’s Robert plays a surgeon haplessly fumbling his lines over a prone body, it is hilarious. I have not laughed so much since the last serious episode of Casualty.

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