When India celebrated the 49th anniversary of its independence from British rule in 1996, its then prime minister, HD Deve Gowda, stood at the ramparts of Delhi's Red Fort and delivered the traditional independence day address to the nation. Eight other prime ministers had done exactly the same thing 48 times before him, but what was unusual this time was that Deve Gowda, a southerner from the state of Karnataka, spoke to the country in a language of which he did not know a word. Tradition and politics required a speech in Hindi, so he gave one - the words having been written out for him in his native Kannada script, in which they made no sense.

Such an episode is almost inconceivable elsewhere, but it was a startling affirmation of Indian pluralism. For the simple fact is that we are all minorities in India. There has never been an archetypal Indian to stand alongside the archetypal German or Frenchman. A Hindi-speaking Hindu male from Uttar Pradesh may cherish the illusion he represents the "majority community". But he does not. As a Hindu, he belongs to the faith adhered to by four-fifths of the population. But a majority of the country does not speak Hindi. And, if he were visiting, say, my home state of Kerala, he may be surprised to realise that a majority there is not even male.

Worse, this stock Hindu male has only to mingle with the polyglot, multicoloured crowds - and I am referring not to the colours of their clothes but to the colours of their skins - thronging any of India's major railway stations to realise how much of a minority he really is. Even his Hinduism is no guarantee of his majorityhood, because caste divisions automatically put him in a minority. (If he is a Brahmin, for instance, 90% of his fellow Indians are not.)

If caste and language complicate the notion of Indian identity, ethnicity makes it worse. Most of the time, an Indian's name immediately reveals where he is from or what her mother-tongue is: when we introduce ourselves, we are advertising our origins. Despite some intermarriage at the elite levels in our cities, Indians are still largely endogamous, and a Bengali is easily distinguished from a Punjabi. The difference this reflects is often more apparent than the elements of commonality. A Karnataka Brahmin shares his Hindu faith with a Bihari Kurmi, but they share little identity with each other in respect of their dress, customs, appearance, taste, language or even, these days, their political objectives. At the same time, a Tamil Hindu would feel he has much more in common with a Tamil Christian or a Tamil Muslim than with, say, a Jat from the state of Haryana with whom he formally shares the Hindu religion.

What makes India, then, a nation? As the country celebrates the 60th anniversary of its independence today, we may well ask: What is an Indian's identity?

When an Italian nation was created in the second half of the 19th century out of a mosaic of principalities and statelets, one Italian nationalist wrote: "We have created Italy. Now all we need to do is to create Italians." It is striking that, a few decades later, no Indian nationalist succumbed to the temptation to express a similar thought. The prime exponent of modern Indian nationalism, Jawaharlal Nehru, would never have spoken of "creating Indians", because he believed that India and Indians had existed for millennia before he articulated their political aspirations in the 20th century.

None the less, the India that was born in 1947 was in a very real sense a new creation: a state that made fellow citizens of the Ladakhi and the Laccadivian, divided Punjabi from Punjabi and asked a Keralite peasant to feel allegiance to a Kashmiri Pandit ruling in Delhi, all for the first time.

So under Mahatma Gandhi and Prime Minister Nehru, Indian nationalism was not based on any of the conventional indices of national identity. Not language, since India's constitution now recognises 22 official languages, and as many as 35 languages spoken by more than a million people each. Not ethnicity, since the "Indian" accommodates a diversity of racial types in which many Indians (Punjabis and Bengalis, in particular) have more ethnically in common with foreigners than with their other compatriots. Not religion, since India is a secular pluralist state that is home to every religion known to mankind, with the possible exception of Shintoism. Not geography, since the natural geography of the subcontinent - framed by the mountains and the sea - was hacked by the partition of 1947. And not even territory, since, by law, anyone with one grandparent born in pre-partition India - outside the territorial boundaries of today's state - is eligible for citizenship. Indian nationalism has therefore always been the nationalism of an idea.

It is the idea of an ever-ever land - emerging from an ancient civilisation, united by a shared history, sustained by pluralist democracy. India's democracy imposes no narrow conformities on its citizens. The whole point of Indian pluralism is you can be many things and one thing: you can be a good Muslim, a good Keralite and a good Indian all at once. The Indian idea is the opposite of what Freudians call "the narcissism of minor differences"; in India we celebrate the commonality of major differences. If America is a melting-pot, then to me India is a thali, a selection of sumptuous dishes in different bowls. Each tastes different, and does not necessarily mix with the next, but they belong together on the same plate, and they complement each other in making the meal a satisfying repast.

So the idea of India is of one land embracing many. It is the idea that a nation may endure differences of caste, creed, colour, conviction, culture, cuisine, costume and custom, and still rally around a consensus. And that consensus is around the simple idea that in a democracy you don't really need to agree - except on the ground rules of how you will disagree.

Geography helps, because it accustoms Indians to the idea of difference. India's national identity has long been built on the slogan "unity in diversity". The "Indian" comes in such varieties that a woman who is fair-skinned, sari-wearing and Italian-speaking, as Sonia Gandhi is, is not more foreign to my grandmother in Kerala than one who is "wheatish-complexioned", wears a salwar kameez and speaks Urdu. Our nation absorbs both these types of people; both are equally "foreign" to some of us, equally Indian to us all.

For now, the sectarian Hindu chauvinists have lost the battle over India's identity. The sight in May 2004 of a Roman Catholic political leader (Sonia Gandhi) making way for a Sikh (Manmohan Singh) to be sworn in as prime minister by a Muslim (President Abdul Kalam) - in a country 81% Hindu - caught the world's imagination. India's founding fathers wrote a constitution for their dreams; we have given passports to their ideals. That one simple moment of political change put to rest many of the arguments over Indian identity. India was never truer to itself than when celebrating its own diversity.

· Shashi Tharoor is the author of Nehru: The Invention of India, and former under secretary general of the United Nations

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