THEATRETHE CRITICS EDINBURGH FESTIVAL All's unfair in war and love

IT IS a wonderful thing to see Frank McGuinness's 1985 play, Observe the Sons of Ulster, originally produced in the Abbey Theatre's Dublin studio, given the full-scale, high-profile production it deserves. It's interesting, though, how dif- ferently it comes across in this context. It is a play about the Ulster Protestants who volunteered to fight in the First World War, confusing that fight with their own sectarian one in Ireland. Yet it was written by a Catholic, performed by a presumably predominantly Catholic cast and first seen in the Republic, thereby swathing all the patriotism and bigotry expressed by its characters in layers of irony. Watching it in Edinburgh in the aftermath of the ceasefire in Northern Ireland, you wonder how it comes across to those who don't know the background.

On a bare, black stage an old man in a white bed lies dying, at first berating and later summoning the ghosts of his dead comrades from the Great War. "Ulster has grown cold, grown lonely," laments old Pyper. "I want to ask you why we allowed ourselves to be led to extermination." His memories of the young men who volunteered with him invade the stage. On comes the younger Pyper (Peter Gowen), an eccentric, provocative, ruling-class joker who understands exactly the power involved in controlling others. Despite the men's initial suspicion of both Pyper's class and his sexuality, his charisma wins through.

From his spirited jesting we move to a scene of engrossing symbolic potency, as the men enjoy their first leave. All are home in pairs, each struggling with a different demon. For Pyper and the young blacksmith Craig (Conor McDermottroe),it's burgeoning erotic love for each other. For Roulson, the anxious priest, it's his crumbling faith. For all, it's finding the courage to take them back to the front; but as the play progresses, the rhetoric of God's chosen people sounds increasingly hollow. At the point of death, each man is prepared to die for his fellow men, while the audience is certain that no cause was ever or can be worth such sacrifice.

Patrick Mason's production is cool and precise, the rough passion and poetry of the writing rebounding off Joe Vanek's too formal, almost sterile set. Only in the concluding moments does it really hit home, when Pyper the old man confronts his younger self in a catechism of outrage for "our land, our people, our spirit, our soil", the idea that inspired the men and the reality that destroyed them.

For Don Carlos, personal love and political love are bizarrely at odds when the woman he loves is married by his father, Philip II of Spain. At a stroke, poor Carlos finds himself guilty of both incestuous lust and treachery. Schiller's 1787 drama is full of such wonderfully testing dilemmas. Prince Carlos inveigles the help of his idealistic friend, the Marquis of Posa who, despite high-minded protestations that friendship is more important than social heirarchy, is politically motivated - he hopes Carlos will lead a rebellion against the religious intolerance of Philip's empire. It is the feisty Princess of Eboli (Julie Saunders) who really loves Carlos, but when she finds that he wants only the queen, the knowledge furnishes her with the means to bring about the ingrate's downfall by telling tales to the already jealous king. And so the plot un- ravels. Despite Robert David Macdonald's easy translation, despite the racing pace that director/designer Philip Prowse imposes on it, and despite the fact that the play lasts three and a half hours, you still feel the need for action replays.

The third member of the triumvirate, Giles Havergal, stands out as the chilly, urbane yet strangely likeable Philip. "You may spare me these advances," he says, disdainfully disentangling himself from his shouting son. "I do not like them and nor do you do them well." Since Benedick Bates's Carlos behaves like this whether in despair or ecstasy, one is inclined to sympathise. The high point is Philip's encounter with Posa (Andrew Woodall), when we see the loneliness of an all-powerful ruler unsure whether it's his wife who is deceiving him, or ambitious acolytes. "I am not, like You, omniscient," he informs God, "I need a friend." But we all know whose friend Posa is. Schiller is a master craftsman, who produces new twists and conundrums just when interest is flagging, but the length and density of the text tries the patience sorely.

For brevity and wit, you're far better off catching Lynn Ferguson's Heart and Sole, a tremblingly poignant tale of a woman whose love leads to tragedy. The quixotic comic imagination of the Reject's Revenge company in Peasouper provides very light relief, while Nichola McCartney's Easy is an unsentimental examination of the issue of date rape.

`Heart and Sole' & `Easy': Edinburgh Gilded Balloon, 0131 226 2151. `Peasouper': Edinburgh Bedlam, 0131 225 9893; all to 2 Sept.