When Simone de Beauvoir was growing up in early twentieth century Paris, her intellect, forcefulness, and wit caused her father to boast: “Simone has a man’s brain; she thinks like a man.”

No doubt he meant it as a compliment; this was an era, after-all, when women didn’t even have the right to vote. Yet his words proved deeply ironic: in 1949 de Beauvoir made history with The Second Sex, her treatise on women’s oppression that fueled the feminist movement in years to come.

In this seminal work de Beauvoir argues “one is not born, but rather becomes, a woman”. Indeed, “woman” is merely a social construct designed by men to subjugate what they considered to be the second sex. Men make women into an “other” by shrouding them in mystery and wrapping them in myth. In her lifetime, de Beauvoir, one of France’s most beloved public intellectuals, could be accused of many things: but no one could accuse her of thinking like a man.

Born in Paris to a conservative lawyer father and a devout Catholic mother, de Beauvoir grew up in a household where teachings and morals chaffed and collided. Rather than feeling claustrophobic, she thrived in an environment of competing ideas. “My father’s individualism and pagan ethical standards were in complete contrast to the rigidly moral conventionalism of my mother’s teaching,” she recalled in Memoirs of a Dutiful Daughter. “This disequilibrium, which made my life a kind of endless disputation, is the main reason why I became an intellectual.”

The other reason was fierce necessity: de Beauvoir was never going to be happy with her lot as it stood. Women in France only received the right to vote in 1945, birth control was legalised in 1967 and higher education was considered to be reserved for men. Yet de Beauvoir, despite the ‘handicap’ of her sex, studied philosophy at the Sorbonne - then only the ninth woman to have ever graduated from the esteemed institution.

On many counts, de Beauvoir felt like she was battling alone. “What a curse to be a woman!” she declared in The Second Sex, quoting Kierkegaard. “And yet the very worst curse when one is a woman is, in fact, not to understand that it is one.” Her ideas were confronting to some - when The Second Sex was published it was put on the Vatican’s Index of Forbidden Books.

The largest impediment to progress, de Beauvoir believed, was that the oppressed do not always know they are oppressed. Instead, they view the very circumstances that keep them down as a natural world order that cannot be changed. De Beauvoir, in contrast, believed that everyone was responsible for their own lives, for drawing their own destinies.

This fed into her existentialist philosophy. In The Ethics of Ambiguity she observed that children have no choice but to accept the values given to them. That paradigm shifts as they get older and they can design their own boundaries and rules, accepting responsibility for their lives. But despite our limitless freedom, most of us automatically retrogress to childhood, choosing safety and security over liberty and risk. The only way to escape this cycle is rebellion: “The oppressed can fulfill their freedom as a person only in revolt.”

And de Beauvoir lived by her words. As a child she once had ambitions to become a nun; religion was a yoke she threw off in her teenage years, remaining a committed atheist for the rest of her life. Marriage, likewise, was too bourgeois, too restrictive, too expected a choice for de Beauvoir to think about making.

In 1929 she met French philosopher Jean-Paul Sartre. De Beauvoir was a handsome, fervently intelligent woman. Sartre, standing at just five feet tall, his diminutive frame swamped in clothes too big for him, was not an obvious choice for a mate. But he was ambitious and clever and daring in his thinking. Both were in their early twenties and they fell in love.

When Sartre proposed, de Beauvoir called the prospect “silly”. Instead they made a pact to stay a couple for life, bound by spirit rather than any outside law drawn up by the State. Their intellectual union - played out in cafés, over lunches, and in the urbane literary circles in which they moved - was reserved for each other.

For de Beauvoir, rejecting marriage was a rebellion against her upbringing. But if her relationship with Sartre was founded on dissent, it was also founded on devotion: in the end, the couple remained partners for more than half a century, right up until Sartre’s death in 1980. As de Beauvoir mused in The Prime of Life: “That which bound us freed us; and in this freedom we found ourselves bound as closely as possible.”

In The Second Sex, de Beauvoir insisted that women could only truly release themselves from the male grip by achieving economic self-reliance. It was de Beauvoir’s academic brilliance that ensured she had a job for life teaching at a lycée, which provided her with the independence she preached.

Yet de Beauvoir was never going to be one to bow to convention. She once wrote: “The writer who is original... is always scandalous; what is new disturbs and antagonises”. Most women, she railed, do not “dare to irritate, explore, explode”, so eager are they to be accepted into the masculine sphere. She did dare. And despite the well-meaning commendations of her father, this was a woman who was never going to let herself be defined as a thinker in merely a man’s world.

From the launch edition of Womankind. To purchase edition #1 in digital format (it has sold out in print), click here.

Thursday, 3 Juillet 1947

I led a very quiet life since my last letter: no cave, no party, no wit. There was a wonderful storm in the country, it was really beautiful. The whole day had been so hot, you really wanted to die, love or work or happiness did not mean anything more. And then came a huge black smoke in the sky, and strange phantasms went by in the dim light, and soon you could not see the sky nor the landscape any more, just a cherry tree beaten by the wind while the rain fell crazily, and thunder shaked the sky. Many trees were broken, flowers killed, the landscape was a battle field… Afterwards, everything was strangely peaceful. Friends came and we had a dinner and long evening: the woman who has swallowed a pin, her husband, the old lady I like so much, and Sartre. But I was not very quiet myself; the storm had gone on my nerves, and I drank much, and, dearest, when I drink much I am no longer sensible at all; when the other friends left I became a storm myself, and poor Sartre was very bored with me who spoke about life and death and everything in a rather mad way. When I am drunk everything seems very tragic and pathetic and terrifying to me – so dreadfully important, and yet without importance since death is at the end; I should knock my head against the walls. I did not knock my head but I spoke and raved late in the night on the peaceful little country roads, and I decided not to drink any more for some time. You see, it has never been very easy for me to live, though I am always very happy – maybe because I want so much to be happy. I like so much to live and I hate the idea of dying one day. And then I am awfully greedy; I want everything from life, I want to be a woman and to be a man, to have many friends and to have loneliness, to work much and write good books, and to travel and enjoy myself, to be selfish and to be unselfish…You see, it is difficult to get all which I want. And then when I do not succeed I get mad with anger…

Simone De Beauvoir, from A Transatlantic Love Affair, Letters to Nelson Algren

From the launch edition of Womankind. To purchase edition #1 in digital format (it has sold out in print), click here.