In a well-known piece of whimsy, Jorge Luis Borges describes a map so detailed as to match in size the territory it represents. The map is mistaken for the land itself until bits wear out, exposing the reality underneath. The faithfulness of representation, Borges seems to be saying, can betray its subject by concealing and so displacing it. I was reminded of this warning when reading the thousand-plus pages of Ramachandra Guha’s account of Gandhi’s Indian career, which follows an equally lengthy volume devoted to his early years in Britain and South Africa.

Guha trained as an economist and his early work was on environmental issues and cricket, subjects he wrote about with elegance and originality. Turning to India’s political past in more recent years, his lucid writing has made him into a celebrity historian there. He is a prominent voice for tolerance, his biographical volumes dedicated to making Gandhi into a liberal icon for a new generation. This is an urgent enterprise in contemporary India, whose caste and religious politics Guha sees as being violently illiberal in character.

The problem with this laudable goal is that Gandhi was not a liberal, and Guha can only make him so by sticking to a familiar script. This involves a sensitive young man schooled into pacifism and vegetarianism among the dissenting Englishmen he met as a student in London, and later shocked into protest by the experience of racial discrimination as a lawyer in South Africa. Returning to India at the beginning of the first world war, he addressed the evils of caste and religious violence, while turning the Indian National Congress into a mass-based political party by focusing on the peasantry.

Eventually, the Mahatma won the enmity of Muslim and Hindu bigots, and was assassinated by one of the latter when the country was partitioned and Pakistan founded. The British either connived in these events or were flat-footed. Apart from a number of minor, previously unknown details, then, Guha’s book repeats the narrative of Richard Attenborough’s 1982 biopic Gandhi. Guha presents no big argument, only small disagreements with Gandhi’s enemies and his own. The new volume’s unambitious character is clear from its subtitle, The Years That Changed the World, from which one cannot tell if the Mahatma created this change or was swept up in it.

Rohino Hattangadi as Ba, Ben Kinglsey as Gandhi, Geraldine James as Mirabehn and Roshan Seth as Nehru in Gandhi (1982), directed by Richard Attenborough. Photograph: Ronald Grant Archive

Gandhi’s early Indian biographers, Dinanath Gopal Tendulkar and Pyarelal Nayar, wrote even lengthier accounts than Guha’s, but their object was to make evidence available for the first time. Guha’s aim seems not to be to open up Gandhi’s life story, but rather to summarise it as a battle against imperialism on the one hand and religious fanaticism on the other. Yet given the Mahatma’s very public life, the only serious question it raises is whether a genuinely new biography of the man is even possible. The story of Gandhi’s life has taken on almost a ritual form in India, with readers proceeding step by step through a much-loved story as through the Stations of the Cross.

Having traversed this Via Dolorosa and been suitably edified, one has to ask: what is this new account meant to accomplish? If we are to take Borges seriously, the answer might be to displace anything radical or at least illiberal about the Mahatma, the very thing with which genuinely new scholarship on him is concerned. But Guha doesn’t engage with this scholarship, seeking instead to defang Gandhi by downplaying the self-described “philosophical anarchist”, who stood for the remaking of social relations by the power of sacrifice.

Confusing non-violence with pacifism, Guha passes over his hero’s difficult ideas in silence. Here is one such idea that undermines the usual view of Gandhi as an old-fashioned moralist: “In this world which baffles our reason, violence there will always be … we cannot escape it simply by running away from it like cowards. Anyone who prepares to run away would do better, instead, to kill and be killed.” Non-violence reclaims individuals from abjection by having them risk their lives in a challenge more excessive than any violence their enemies can threaten.

Gandhi spoke of protecting truth at the cost of life, and made its sacrifice the very essence of non-violence

Guha can only praise his hero by diminishing him, confining his teachings to “normal times, normal places, and against normal rulers”, and in the process normalising both colonial rule and racial violence in such places as the pre-civil rights US and apartheid South Africa. He does so by contrasting them with nazism as an exception he thinks challenges Gandhi’s universal claims, and defining non-violence as an occasional instrument to protect life – the great liberal value. For Gandhi, however, truth was the ultimate value and life only its indirect consequence. He spoke of protecting truth at the cost of life, and made its sacrifice the very essence of non-violence.

In his autobiography the Mahatma even downplays the Jallianwala Bagh massacre of 1919, when Reginal Dyer ordered his troops to mow down hundreds of unarmed men and women in Amritsar, and claims to be more horrified by the humiliation (and therefore untruth) willingly borne by Indians elsewhere in the city: “In Amritsar innocent men and women were made to crawl like worms on their bellies. Before this outrage the Jallianwala Bagh tragedy paled into insignificance in my eyes, though it was this massacre principally that attracted the attention of the people of India and of the world.”

Guha’s book comprises three elements. First, there is a summary of the Mahatma’s political career, a narrative interrupted now and then by the second element – stories from his private life. Of these, Gandhi’s never-quite-erotic relationship with a married woman, Sarala Devi Chaudhrani, takes pride of place. There is not much to report, but this doesn’t stop Guha from bringing her into the story frequently and imagining what might have been, if only to show that his hero possessed secrets about which no previous biographer has known. The more salacious story about Gandhi involves his experiments, late in life, of sleeping naked with young women in order to test his chastity. Apart from provoking jealousy among his ‘bed partners’, these experiments do not seem to have been traumatic. Yet they were a scandal even at the time, with a few of the Mahatma’s male disciples leaving him over the issue. One of them, the anthropologist NK Bose, would later write that Gandhi’s wife and close friends having died, he no longer enjoyed any intimate human relationships. This was the only way he could shake off the solitude of his saintliness to become human and so fallible again.

Gandhi with two of his granddaughters, Delhi, 1948. Photograph: Alamy

The views of Gandhi’s contemporaries make up the final element. Most important seem to be the impressions of westerners, an audience both represented in the book and addressed by it. There is no serious consideration of the Mahatma’s reception in other colonised societies, with the encomia of six African leaders squeezed into a single paragraph while Einstein gets two and even Malcolm Muggeridge has one to himself. In an anecdote revealing of the importance to him of a middle-class, Euro-American readership, Guha is surprised that a Dominican waiter serving him in New York could recognise a photograph of the great man.

Why does the book need to demonstrate Gandhi’s importance to the west? Its author devotes nearly two pages to Time magazine’s choice of the Mahatma for its 1930 cover, from a list that included the golfer Bobby Jones, Sinclair Lewis, Joseph Stalin and Al Capone. Guha is at the same time touchy and craven in his attitude towards the west’s relationship with his subject and with India. Of all the extraordinary events in Gandhi’s life, he is “moved almost to tears” only by the good manners of an English judge sentencing the Mahatma for sedition in 1922.

The narrative ends with an avalanche of testimonials, in which the contrition of Gandhi’s enemies after his assassination is matched by the righteousness of his friends. Left unreconciled are the Hindu nationalists whose ideological descendants rule India today, and against whom Guha appears to have written his biography. But having neutralised the Mahatma’s politics, Guha is unable to recommend his methods against them. His book does little more than veil India’s present with a fantasy of non-violence safely ensconced in the past.

• Faisal Devji’s The Impossible Indian: Gandhi and the Temptations of Violence is published by Hurst.

Gandhi 1914-1948: The Years That Changed the World is published by Allen Lane. To order a copy for £34.40 (RRP £40) go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.