Something very interesting happened in Irish theatre in the 1960s and 1970s. One of the most basic elements of a play is a character: a coherent personality who affects and is affected by the action. But this basic idea started to break down. Central characters became porous or multiple. Gar O'Donnell in Brian Friel's Philadelphia, Here I Come! is split into public and private selves. Tom Murphy's plays feature two men who are really the broken halves of a single personality. (Missus in Conversations on a Homecoming , for example, remarks of Michael and Tom that the two of them would make "one good man".) The protagonist of Hugh Leonard's Da is split in time, appearing simultaneously as a past and present self. This tendency is one of the things that makes Irish plays of that period so exciting.

When did it start? Before last week, I'd have said that it begins in earnest with Philadelphia in 1964. Now I'd say it begins much earlier, with Teresa Deevy's rivetingly strange 1936 play, Katie Roche . It's a drama in which the audience is confronted by a self that utterly refuses to cohere and that therefore seems like a seminal work of modern Irish theatre. That many readers will respond to this suggestion with a question, Teresa who?, is a mark of how fractured our sense of that theatre can be.

Deevy was the great white hope of the Abbey in the mid-1930s. Katie Roche was included alongside the staples of O'Casey and Synge on the Abbey's tour of the US in 1937. And then she was simply dropped, suddenly and without explanation. Deevy's next play, Holiday House , was accepted by the Abbey but then shelved, and she was never told why. It is easy enough, to see that she didn't fit in with the reactionary atmosphere of the national theatre, however, and that her work raises startlingly blunt questions about the role of women in Éamon de Valera's Ireland.

No coherent exploration
That breach has never been properly repaired. The Abbey has twice staged Katie Roche in recent decades. It was directed by Joe Dowling in 1975 and by Judy Friel in 1994, with a brilliant Derbhle Crotty performance at its centre. But there has been no coherent exploration of Deevy's work as a whole by any Irish company. Instead, the Mint Theatre in New York, which specialises in rediscovering lost work, has engaged in what it calls the Teresa Deevy Project. Its artistic director, Jonathan Bank, working with the Deevy family and with Chris Morash of NUI Maynooth, where there is now a Deevy archive, produced Wife to James Whelan in 2010, Temporal Powers in 2011 and now Katie Roche , which opened last week. The Mint has also staged readings of four short plays and is publishing two volumes of Deevy's scripts.

There are good reasons, both social and artistic, why Irish theatre should pay attention to this project. Socially, Katie Roche resonates powerfully with the Taoiseach's recent apology to the Magdalene women. Katie was born out of wedlock, and her mother is spoken about but never seen. Katie has been working in the convent: one line of hers, "When you'd be working for nuns you'd never be finished," has a startling immediacy. And the world in which she lives sees Katie as a danger. Her father, a bizarre wandering holy man, says towards the end that "She's in great danger . . . she doesn't know how wild she is . . . A girl with such a parentage."

But the interest of the play is much more than sociological. The figure Katie reminds me of most is Ophelia from Hamlet , a young woman whose identity is entirely shaped by men: her father and her would-be husband. Katie (superbly played by Wrenn Schmidt, who plays Julia in the current season of Boardwalk Empire ) has fantasy versions of herself, in which she is a saint, a lover or the child of "great people". But she has no fixed self; such a thing is a luxury her society will not allow her.

This is what makes the play strange. Its central character has no character. She responds impulsively to whatever is put before her and those impulses themselves are drawn between a half-formed sexuality and religious mysticism. In another context, this would be bad writing, but here it is the point of the play, for what we see is Katie being pulled between three men: her father, the boy who would be her lover, and Stanislaus, the middle-aged architect she marries for no better reason than that he wants her to.

The hard thing is to know just how strange to make the play, for it hovers between apparent naturalism and an almost lurid expressionism. Do you play up its odd jumps of logic, its central absence, its almost mythological depiction of patriarchy? Or do you try to make it work for what it purports to be; a three-act domestic drama? Banks decides to go for the latter, and the choice is logical, both because the play has to re-establish itself in the US and because he has in Schmidt an actor who can bring a wealth of naturalistic detail to Katie's quicksilver persona. This involves some sacrifices, especially of the weirdness and terror of Katie's father, but it holds together very effectively. For a play of whose fascinating central character we can never say the same, that in itself is a significant achievement.

fotoole@irishtimes.com