Paul Gilroy has good claim to be the most influential intellectual writing in Britain today. His first major book There Ain't No Black in the Union Jack: The Culture and Politics of Race and Nation (1987, 1991) was an inspiration to a generation of young students and artists in the 1980s who wanted to be black and British. A signature of its impact is that even the title of this pioneering study of national identity in post-empire Britain became absorbed into the culture without reference to the author.

A series of pivotal books has followed, along with a host of essays, reflections and collaborations that cohere into an unmatched and still evolving body of work. The second key text in Gilroy's career was The Black Atlantic: Modernity and Double-Consciousness (1992), which transformed academic geography and history. It made clear that Gilroy really had learned Hegel's lesson that only the slave truly understands a freedom which the master simply enjoys. As important, he had listened long and hard to the music in which the slaves and their descendants had articulated this understanding.

The result was nothing short of an intellectual revolution, as the Atlantic became in Gilroy's creative reimagining the geographical setting not simply of the middle passage which transported millions of Africans to slavery in the "new world" but also of the routes through which their descendants' music and thought travelled back to Europe. Like many great ideas, it had the feature of being stunningly obvious once elaborated. The Black Atlantic became an instant intellectual classic.

Gilroy's third book Against Race: Imagining Political Culture beyond the Color Line (2000) was an epic investigation of the patterns of racial thinking and discourse that concluded with a plea for a "planetary humanism" beyond the imprisoning categories of current discourse. The work did not have anything like the impact it deserved, and the same appears true – so far, at least – of his latest study, After Empire: Melancholia or Convivial Culture? (2004).

It is worth pondering the reasons for this contrast in impact. Gilroy's earlier two books were challenging to inherited nostrums of conservative monoculture, but they also went with the grain of a developing political and historical awareness; the resistance to putting black experience at the centre of discussion of Britishness was confined to the archaic and the racist, while the field of Atlantic history and geography might have invented Gilroy if he didn't already exist. By contrast, these two more recent books run up against every kind of vested interest – academic and literary, media and political – as they assail some of the most cherished self-images of a complacent age.

The radicalism of these latest works, that is, targets a different institutional and cultural order. In the three decades since Gilroy started writing, centuries of exploitation and inequality have been addressed through the carving out and allocation of slices of the academic and political pie on the grounds of race. Departments of African-American studies in the universities of the United States have become the educational equivalent of the bureaucratic apparatuses pledged to the goal of racial equality.

Gilroy, while not wishing to dismiss all of the motives behind such developments, argues that it is a terrible mistake to reproduce (politically as well as intellectually) the fundamental divisions once used by Europeans to dominate the globe. Race here becomes simply a code, the key to which is the fundamental inequalities between colonisers and colonised, those who own and those who labour. To use race as a way of dividing the world is to accept this code.

Colin MacCabe is distinguished professor of English and Film at the University of Pittsburgh and professor of English at the University of Exeter, England. He also edits Critical Quarterly

Also by Colin MacCabe in openDemocracy:

"James Joyce's Ulysses: the end of masculine heroism" (July 2004)

"Mumbo-jumbo's survival instinct" (February 2005)

"Zadie Smith and Salman Rushdie: writing for a new world"
(October 2005)

"London's eye on world cinema" (October 2005)

From post-race to post-empire

In Against Race Gilroy took on the pathological developments of that most lyrical of slogans "black is beautiful", arguing that many of the developments of American black culture which might look self-affirming were simply continuing the polarising analysis of humanity which had produced two races in the southern United States. If the book was unsettling to many American academics, the diagnosis of the British predicament in After Empire is equally unwelcome to the country's ruling New Labour establishment.

Gilroy's perspective would indeed view the "new" in New Labour – an artful rebranding of the party led by Tony Blair that has governed the country since 1997 – in terms of his own overall argument, as another of the many symptoms of Britain's pathological inability to come to terms with its past. The national condition that results is a constant attempt to divert itself in the present so that it does not have to face the reality of loss.

It is that loss – so Gilroy argues – which is the central social, political and cultural fact of current British society. It is the inability to mourn the loss which prevents the elaboration of a more joyful present in which the post-imperial reality that British people today inhabit could be embraced for what it is; one in which race would, in a utopian moment, cease to have any meaning. For the meanings of race are produced by the unfinished business of empire, by the division of the world that it assumed and elaborated.

After Empire is a very powerful book written in a kind of philosophical rhapsody which makes real music. Like those two other masters of English-speaking Hegelianism, Frederic Jameson and Raymond Williams, Gilroy almost never cites individuals in his arguments. Instead he opts for the description of formations of thought, and the descriptions are powerful and compelling. There are no more powerful arguments in English for the centrality of the colonial experience to western democracies. There are no more compelling analyses of Britain than those where Gilroy, exploring his central theme of the unmourned end of empire, ranges from the centrality of the second world war in the national imaginary to why the innovative television series The Office was set in the anonymous west-of-London town of Slough.

Gilroy is right to identify the deep gravity of Britain's condition. There are few historical examples of a people electing as a leader a man that they know to be both mendacious and corrupt, but the election result of May 2005 also demonstrates clearly how depressed a people we have become. A recent example on the cultural level is the hostile English reception of Neil Jordan's remarkable movie Breakfast on Pluto – which, together with the director's The Butcher Boy (to which this latest film is a sequel) composes an important element in the Irish people's working through of their own blocked historical memory.

A possible explanation for this pathological critical reaction to Breakfast on Pluto is that England's (the shift of register seems appropriate) repressed historical memories are now so condensed and displaced that the very thought of any such liberation is terrifying. More likely and more directly, two brief scenes in the movie demonstrate Gilroy's thesis that the colonial experience of military murder and police torture are not exceptions but the rule of the imperial state. And this for Gilroy is not a question about the past: Guantánamo Bay and Abu Ghraib are in his terms the continuation of conceptual divisions fundamental to the imperial mission.

A history for the future

If After Empire is immensely powerful it does not answer all the questions that it raises. Gilroy is surely right that the "planetary humanism" he proposed in Against Race and reaffirms here is now the only hope for a world on the eve of destruction, but he asserts rather than argues for it. The theme gives the book much of its power, for Gilroy is able to write as though there is a spectre of hope haunting our current desperate existence. But why man should be the measure of all things is neither asked nor answered. This epistemological assumption has an anthropological parallel in Gilroy's faith that if the terrible histories of European colonialism were properly remembered then all national and racial enmities would evaporate.

It would be possible in principle for Gilroy to produce a contemporary version of Pascal's wager: that we should act as if there is hope because even if hope (like God) does not exist, its very possibility is worth a bet. Gilroy eschews such probabilistic reasoning in favour of an invocation, a vision of a world beyond race which finds sanction neither in a traditional Christianity (where one perfect man redeems our sins) nor in a standard Marxism (in which a new class can only find its liberation in a universal emancipation). Gilroy's faith in the human is as impressive as it is irrational.

But if, following Pascal, we choose to bet with Gilroy then there are still further problems. All Hegelians – and here FH Bradley would be as relevant an example as Raymond Williams – flee concrete social reality, and above all immediate, detailed social policy. Any such policy is literally unthinkable to minds locked in contemplation of the unfolding of world contradictions – so mired would the Idea become in a Being which it always regards as insufficiently complex. Gilroy's book offers no indication of how to break through to the other side of our depression; how to begin that exercise of "re-memoration" which would deliver the "conviviality" (a key concept in Gilroy's lexicon) which the British reject so obsessively and compulsively.

In any case, any wise Hegelian knows that the transformation of a whole culture is an impossible project. Cultures change and develop with an infinite set of determinations, which are by that very definition unknowable in their entirety. But good Marxist empiricists have to start somewhere, and it is now time for scholars across the humanities and social sciences to call for a common history curriculum – from play-school to school-leaving examinations – which focuses on the British empire.

Paul Gilroy, professor of social theory at the London School of Economics, writes on openDemocracy:

"The American jihad" (September 2001)

"Diving into the tunnel: the politics of race between old and new worlds" (January 2002)

"Raise your eyes" (September 2002)

"Neither Jews nor Germans: where is liberalism taking us? " (June 2002)

"Ali G and the Oscars" (April 2002)

"Melancholia and multiculture"
(August 2004)

This curriculum should not be heavily coercive; it should also (in the best traditions of English education) allow a great deal of local determination. It must start, however, with an event of world-historical importance: the occasion on 30 January 1649 when a people executed their king with an attempt to follow the due process of law. It would then study Cromwell's terror campaign in Ireland and the destruction of the Scots' state independence at Dunbar, then track the way that the chairman of the council of state turned to the business of commerce and drafted the Navigation Act of 1651 which provided the legal basis for the British empire.

By thus uniting the most important event in English political history with the military and legal basis of empire, it will become possible to begin to teach all the children in Britain how they have come to be sitting together in their classrooms.

In any such history, students would range across the world as the contact between English, Scots and British traders and settlers and native peoples embraces every continent. In telling this story in any way which is likely to interest children always prepared to be bored in a classroom, the issue of generic tribal characteristics pertaining to national behaviour – "tribal", because to describe them as national or racial is already to commit a historical or biological falsehood – will become unavoidable.

To say, for example, that an Irishman likes his drink or that an African has problems keeping chronological time is false if it is construed as a proposition of the form “for all x if x is an Irishman then x is an alcoholic” but if we produce it as “if x is an African then x has a much greater probability of having problems with punctuality than the rest of the human race” then it begins to look like an important truth. The mechanisms which produce these truths can be debated – to sit in an island where it always rains and to have the shit kicked out of you by the English for 700 years might drive any people to drink.

Indeed, it is doubtful that the "stories" Gilroy accurately judges so vital to Britain's future well-being can be told without recourse to these generic types. My only real criticism of Gilroy's book is that a very thin whine of political correctness runs through it that stands in the way of the educative and cultural programme that he proposes.

However, this cavil is minor besides Gilroy's towering achievement of thinking originally and afresh about race and empire, colony and homeland. I have read and reread After Empire and each time it yields fresh insights and provocation. It goes against the political grain of the race-relations industry, the academic grain of African-American studies, and the ideological grain of New Labourism, and is all the better for it: for if we go with the grain we are headed for Armageddon.