Books: All that delirium of the brave: Romantic Ireland's dead and gone - or is it? G J Watson applauds a stand against stereotypes - 'Paddy and Mr Punch: Connections in Irish and English history' - R F Foster: Allen Lane, 22.50 pounds

This enormously rich and humane collection of essays is unified by a pervasive theme: that 'cultural diversity and cross-channel borrowings are implicit in Irish history, and cannot be denied by piety or suppressed by violence'. Nationalism in its more rabid forms - and the same is true of its orange version, militant unionism - is a denial of memory; though both stridently claim to preserve intact the very essence of a people's experience, in truth they war on the past, eliding the facts that do not fit, ironing out their own contradictions, writing out of history the people whose views challenge their own predestinate theologies. Nationalism and unionism are thus great simplifiers, creating and nurturing the stereotypes with which we are all wearily familiar - jackbooted Britain, suffering Hibernia; just and forbearing Britannia, Paddy the Ape with the dynamite under the shabby jacket.

The good historian is on the side of memory; like Wordsworth's ideal poet, he is 'an upholder and preserver of things silently gone out of mind and things violently destroyed'. Roy Foster is aware that the history of relations between Britain and Ireland is vastly more complicated than the simplifiers would allow, that there are 'varieties of Irishness' (the title of one of the essays collected here) as well as varieties of Britishness, and that the cultural and political interactions between the two islands are rarely predictable (whatever we might assume about Ian Paisley or Gerry Adams).

Thus, John Leech and R J Hamerton, two of the Punch cartoonists who brutally emphasised Irish apishness, were themselves Irish. Foster also points out correctly that 'Irish identification with the land, its unique appearance, its light and shade . . . owes much to English-derived romanticism', amusingly citing as evidence the lyrical description of bivouacs in the Tipperary mountains from a book by the intransigent republican, Ernie O'Malley. Elizabeth Bowen, working for the British Ministry of Information during the Second World War, turns out to be nevertheless a stout and eloquent defender of Irish neutrality. Parnell, the uncrowned king of Ireland, constructed a cricket pitch ('English cricket', my teachers used to hiss) in Mrs O'Shea's back garden.

Foster garners these details in no spirit of Olympian detachment, but as a way of making Louis MacNeice's life-giving point about 'the drunkenness of things being various'. (MacNeice is another distinguished Irishman who would only be awarded a bare entry on the Index of Irishness which Foster so spiritedly attacks.)

Foster is a superb historian because he is such a good literary critic, and because he knows that history will always lose out to literary myths and constructions, but keeps on fighting anyway. The relation of the two disciplines is tellingly put: 'We must not shy at the fact that we cull the past from fiction rather than history and that art out of the very necessity to compose a picture cannot but eliminate, edit - and so, falsify.'

This is not Foster, but Elizabeth Bowen; and the essay 'The Irishness of Elizabeth Bowen' is the best piece I have read on her. Bowen is at least as interesting as Jean Rhys, currently number one in the Irish universities' hit parade of post-colonialists, and I hope that Foster's brilliant essay will rescue her work from the patronising attention it gets in academic Ireland - 'A good Protestant woman on a horse, fallen among Cyril Connollys' would be only a slight caricature.

Virginia Woolf saw the young Bowen as 'a very honourable horse-faced, upper-class hard constricted mind'; but as Foster tellingly shows, her fiction is based on a lively awareness of what she called 'the horror beneath the surface'. Her real themes are dispossession, double-crossing, cruelty and betrayal. Foster's linking of her to Yeats is masterly - she longed, like him, for 'order, abstraction, classical symmetry, yet wrote most brilliantly of dislocation and conveyed in her best writing a sense of chaos'.

The essay shows Bowen's work as emblematic of her divided inheritance - on the one hand, the world of the Anglo-Irish gentry 'long bereft of raison d'etre, bound to a history of mingled pride and bad conscience, as Foster puts it with characteristic felicity; on the other hand, the world of literary London and Oxford. Bowen's story also lights up the larger theme of the whole collection - the enabling diversity of Irish writing and attitudes. A sub-theme here, taken up in another essay entitled 'Protestant Magic: W B Yeats and the Spell of Irish History' is the Anglo-Irish interest in the occult and the gothic (what Auden referred to as the Southern Californian side of Yeats): all this mirrors a sense of displacement, a loss of social and psychological integration, and a quest for a substitute version of the half-hated, half-envied Catholic access to a more easily come-by magic'.

The Bowen essay, along with extended discussions about Thackeray, Trollope, Le Fanu, Bram Stoker, Lady Gregory, Synge and Yeats, shows how well literature can illuminate history as well as being illuminated by it. Foster is never reductive, and writes with a clarity and elegance reminiscent of a more sinewy Matthew Arnold. He will not thank me for that comparison, because in the eyes of many Irish critics I have just used a 13-letter swear word; but discerning readers will be grateful that here we have an ironic liberal humanist, who refutes the 'fashionable idea that the historian / writer is in corrupt and unconscious collusion with the text, and that reference to an ascertainable body of fact is a delusion of the late bourgeois world'.

Once all readings are negotiable anything goes, and what usually goes - or comes back - is the old antipathy, the old atavism. If, as some critics in Ireland believe, the liberal humanist ethic is a cultural fantasy, Foster's essays are a shining refutation of them. In writing of Ireland's contentious history, to express the qualifications which must shadow every generalisation is not only scholarly, but also brave.

There is nothing in the least solemn about the writing (despite my reference to Arnold). Foster has a great eye for the telling quotation. Here, for example, is Bowen on the relationship between Ireland and England - 'a mixture of showing off and suspicion, nearly as bad as sex' or on the Anglo-Irish - 'the only children' of Irish history. Here is the Catholic Bulletin of 1925 lamenting the past: 'it is very different in Ireland now to those old days when the poorest Catholic family would, on assembling in the evenings, discuss scholastic philosophy and such subjects.' Ah yes, I remember it well.

These essays display profound historical knowledge, impartiality and a generous sympathy with their diverse subjects which never becomes collusion. They are somewhat uncomfortable proof that some of the best literary criticism today is being done outside departments of English.

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