"Avoiding danger is no safer in the long run than outright exposure. The fearful are caught as often as the bold."

I was intrigued to find a reference to Helen Keller in Pat Stack's Socialist Review column, "Casting Off Stereotypes", in January. My first memory of her is also a cinematic one. As a small child I can vividly recall my mother telling me of a film she had seen called The Miracle Worker about a teacher who had taught a little deaf and blind girl to communicate through touch. My initial reaction was one of antipathy towards this "rival child" who had set a standard for "bravery" that I could never live up to. Now, I believe Keller was "remarkable" but it is the enduring legacy of her political activism that should be acknowledged rather than her "triumph over tragedy".

Many of those who have heard of Keller probably think of her as she is portrayed in The Miracle Worker - the "feral" child rescued from a world of silent darkness. Given the dominant romanticised and one-dimensional narrative of Keller's life, it is no surprise that this hagiography ends as she reaches maturity. It allows the inconvenient truth of her commitment to civil liberties, trade unionism and international socialism to be airbrushed out of existence.

Helen Keller was born in the US state of Alabama in 1880 and became deafblind at the age of 19 months. There is little doubt that had she been working class she would have been institutionalised. As it was, her parents faced enormous pressure to place her in an asylum but were just affluent enough to be able to employ Anne Sullivan as a home teacher for seven year old Keller.

Sullivan began communicating with Keller through finger spelling on the girl's palm. A revelation happened very quickly when Sullivan held Keller's hand under running water, simultaneously finger spelling w-a-t-e-r, and the child was able to relate word to object.

The significance of this event needs to be put into context. It was neither heroic nor miraculous but it was an epiphany of understanding that caught the public imagination and made a celebrity of a disabled child. The first biography of Keller was written when she was just ten and her fame opened up huge opportunities in terms of her intellectual development.

She later wrote, "I had once believed that we are all masters of our fate - that we could mould our lives into any form we pleased... But as I went more and more about the country I learned that I had spoken with assurance on a subject I knew little about. I forgot that I owed my success partly to the advantages of my birth and environment. Now, however, I learned that the power to rise in the world is not within the reach of everyone."

Keller was an academic child who went on to study at the Perkins Institute for the Blind and then a specialist school for deaf children, followed by a mainstream sixth form college. Her education was paid for by privileged benefactors and this led to a classic example of biting the bourgeois hand that fed her. She was a university student at Radcliffe College when she and Sullivan met John Macy, a lecturer and radical journalist, who was to be a formative influence on both women. Macy and Sullivan married after Keller's graduation and the three of them lived together for several years. Macy introduced Keller to Marxist theory and she joined the US Socialist Party in 1909 and the Industrial Workers of the World (IWW) in 1912.

Keller's early career was as an author, journalist and public speaker and she used this as a platform for her political campaigning, attracting an immediate backlash from the ruling class. A fawning media which had portrayed her as courageous, celibate and saintly attacked her naivety. The previously effusive editor of the Brooklyn Eagle stated that her "mistakes sprung out of the manifest limitations of her development".

Keller's response was to pull no punches: "At that time, the compliments he paid me were so generous that I blush to remember them. But now that I have come out for socialism he reminds me and the public that I am blind and deaf and especially liable to error."

Writing in Why I Became an IWW, published in 1918, Keller made it clear that her commitment to feminism, pacifism and international socialism was fuelled by her anger at the injustice, poverty and discrimination faced by millions of disabled people:

"I was appointed on a commission to investigate the conditions of the blind. For the first time I, who had thought blindness a misfortune beyond human control, found that too much of it was traceable to wrong industrial conditions, often caused by the selfishness and greed of employers."

From 1924 onwards Keller concentrated almost exclusively on campaigning for the American Foundation for the Blind. Consequently, most of her biographers and the major charities that allegedly work on behalf of visually impaired people dismiss her commitment to radicalism as a youthful aberration, if they refer to it at all. The nearest any of the numerous documentaries, television programmes and cinematic depictions of Keller's life get to exploring her political identity is a single oblique mention of her as an "activist for social equality".

However, the FBI file on Keller confirms that her internationalist sympathies were immutable throughout much of her life, as were her friendships with members of the American Communist Party. She courted a storm of controversy in 1955 by sending birthday greetings to former IWW organiser Elizabeth Gurley Flynn, who was serving a two-year prison sentence as a result of witch-hunting of communists.

In October 2009 a statue of Keller and Sullivan was unveiled in Washington to a predictable chorus of platitudes. "Some are still dismissed and cast aside for nothing more than being less than perfect," Senator Mitch McConnell said at the unveiling ceremony. "The story of Helen Keller inspires us all."

But which story is that?