That's not to say that it's beyond criticism: there are occasional moments in Moira Buffini's virtuoso performance, as the mother who has killed her baby son, that feel incongruously stagey; and the pacing of the script is uneven (in particular, the lead-up to the murder feels slightly rushed).
But as an example of observation and of pure imagination, the ability to see inside somebody else's head, it is stunning. Long before the end, you see not simply why Shirley killed a son whom she certainly loved, but why killing him might have seemed a rational response - even the only response - to her situation. It's a deeply compassionate and moving play, as well as, at times, a very funny one. See it.
Democracy, a play by the Canadian John Murrell now being given its British premiere at the Bush, feels almost lightweight by comparison, though it's all about heavyweights. This is a historical encounter play - the genre that Terry Johnson has built a career on. The meeting here is between Walt Whitman and Ralph Waldo Emerson, in a clearing in a wood near Washington DC in the summer of 1863, when Whitman was working as a volunteer in a military hospital. Here they debate poetry, life and death, optimism and pessimism, in company with a pair of young soldiers Whitman has brought along.
Whitman fans can have a good time spotting the way the action corresponds with the poems in Drum- Taps; otherwise, the main pleasure is in Robert Jones's transformation of the theatre into a forest. On the other side of the Pond, a debate between Emerson and Whitman presumably has more intrinsic interest than it does over here. Stranded in west London, it looks wordy and heavy-handed - it's hard, for instance, not to snigger at Whitman's anatomically detailed comparison of a strapping youth with democracy (particularly the 'rude, presumptuous knees') - and the issues debated feel remote and irrelevant.
The Old Ladies suffers a similar problem: at the heart of Rodney Ackland's Thirties spiritual thriller is a clash of moralities that now seems creakingly old-fashioned. Three old women are marooned together in a shabby provincial lodging-house, surrounded by darkness and screaming winds; batty Agatha (Miriam Karlin) covets an amber carving owned by nervy May (Faith Brook), and will do anything to get it; lovely Christian Lucy (Doreen Mantle) sits waiting for the son who will come and save her from penury.
All three performances are pleasing, though Karlin looks far too spry. But the tension takes too long to build, and finally seems just to seep away. Cut by a good hour, this might be a good play; as it is, it looks ready to be pensioned off.
'Jordan' continues to 10 April at BAC, London SW11 (071-223 2223). 'Democracy' to 16 April, The Bush, W12 (081-743 3388). 'The Old Ladies' to 2 April, Greenwich Theatre, SE10 (081-858 7755)