Mother Clap's Molly House, Aldwych Theatre, London; <br></br>Humble Boy, Gielgud Theatre, London

Sons and mothers

There's an old wisdom that maintains that the military top brass are always fighting the previous war. If, the theory goes, they were equipped with better mental radar, they would already have developed the technology necessary to knock out the enemy in the conflict waiting to happen. I was reminded of that idea when watching the National Theatre's two latest transfers to the West End: Mark Ravenhill's Mother Clap's Molly House and Charlotte Jones's Humble Boy, the latter just having picked up the Critics' Circle award for best play. I didn't give my vote to either. In a year that included Martin McDonagh's tripe-tremblingly trenchant Lieutenant of Inishmore and Robert Lepage's The Far Side of the Moon (which brilliantly unites the audience in the sense of being together and inalienably apart), it felt to me that to vote for Mother Clap or Humble Boy was to advertise how you hadn't been paying proper attention.

Mother Clap I have great respect for – but don't exactly enjoy. It comes across as a tendentious sermon (monogamy is the only way out of Despair's Morass, but so difficult to achieve) wrapped in chubby layers of feel-good cladding. They were actually handing out lollipops to the punters on opening night. I said to the youth who offered me one: "Well, if it's laced with strychnine – fine. That would at least be in keeping with the deep spirit of the show." For perfectly honourable reasons, people seem to have got themselves into false positions here. Ravenhill has huge potential as a writer of new material. Ditto, as a director of such, Nick Hytner, artistic director designate of the National Theatre. But there's a feel-good factor built into both play and production that's a big downer to anyone save an utter airhead.

The reason, though, why the event is compulsory viewing is Deborah Findlay's quite brilliant performance as Mother Clap, the lonely, childless woman who first blossoms into a kind of glorious fag-hag as the "mother" of a bawdy house of cross-dressers and then realises that this occupation is not emotionally nourishing enough. Snouty, frizzy-haired, pitch-perfect as she negotiates the slithery slopes between needy innocence and nascent experience, Findlay is beyond praise – never coarse. Indeed, she's delicate and sensitive even in the hearty bits when she's supposed to have fooled herself that being transgression's impresario is not just a means to an end but the end itself.

Like Findlay, Simon Russell Beale is more talented than the material in Humble Boy, the play he is not just gracing but irradiating with his haunting and hilarious sense of humanity. His skill compensates for the largely technician idea of humanity in the piece itself. My guest made the good point that he had enjoyed himself, yet felt a bit ashamed of liking the play, because it seemed like accepting the kind of exorbitant compliment that comes with a worrying ulterior motive. The ulterior motive (which John Caird's clever production effectively disguises) is to get into the West End, which it has, in a big way. The casting of Felicity Kendal as the bitchy Gertrude to Russell Beale's bumbling Hamlet is funnier than any of the lines. Mother? Bitchy? Simon Russell Beale? My guest was once again a tonic. "You would be more convincing as Beale's mother," he laughed. And he meant it (Russell Beale and I, though only four years separate our births, could be first cousins parted by 15). But fundamentally, it's not the fault of Kendal, who does a sterling job in suppressing all her usual tendencies of wanting to be a darling little chipmunk stroked to death by her public: no, to blame here is the canny commercialism of whoever exposed her to this kind of review in the first place. She's still an embarrassment (look at the two of them – could there possibly be any genetic connection?). But she's a trouper, and she needs to be.

Along with Russell Beale, the star is Marcia Warren, who plays Kendal's doormat of a friend. Has Warren ever given a performance that didn't so wonderfully serve the play that you can quite overlook the fact that there's an actress in there somewhere? Warren is the one who should be showered with awards – not Jones, who, despite the awards and the unfelt and mugged-up science, is still, in creative terms, fighting the Battle of the Bulge.

'Mother Clap' to 16 March (0870 400 0805); 'Humble Boy' booking to 18 May (020-7494 5065)