The Cellar Door: Jean-Paul Sartre and Simone de Beauvoir continue to be one of the most fascinating and compelling couples of the 20th century. They challenged the cultural and social expectations of their time and contributed to the tides of change on how we view life, women and relationships.

The relationship between these two exceptional figures began with a heated competition over the receivership of the aggregation of philosophy, the elite French graduate degree, and from that moment on the two became inseparable, lifelong companions right up until his death.

In speaking of him, she declared that despite all her many books and literary prizes, whatever her role in the

women's movement, her greatest achievement in life was her relationship with Sartre - "philosopher, playwright, philanderer".

Their relationship was romantic but by no means monogamous. Very early on, Sartre suggested that, although what they had was an "essential love", they should be allowed to experience love affairs outside of their relationship.

Unbelievably, de Beauvoir accepted. This is what always surprised me about this couple - for a woman who so fervently fought for rights of women to simply allow, God forbid, a man to walk all over her and run around with his paramours.

One could be forgiven for thinking that their relationship was a squalid business, in that they shared various partners, that they were actively encouraged by the other to be unfaithful and that their relationship even had voyeuristic elements to it. However, it is important to look beyond that and see that this legendary couple had a generous, open and respectful love for each other.

De Beauvoir described Sartre as her "dear little being" (an in-joke from his work Being and Nothingness), and her overarching love for a man who was never sexually faithful to her is evident, although by the end of the war their sexual relations were virtually nonexistent.

What is vital to understand is that although de Beauvoir accepted something that most women would find demeaning, her dependence on Sartre was certainly not passive: it was something that they both shared.

This acceptance that men and women need one another is something that all people, feminists included, should realise. Being a feminist is not about fighting mankind but about working to create equality in how we think about love and sex. On her deathbed, she said: "My death will not bring us together again. This is how things are. It is in itself splendid that we were able to live our lives in harmony for so long."

The newspapers exclaimed on the morning de Beauvoir died: "Women, you owe her everything!" They were most certainly right. For her, her greatest achievement was her life with Sartre; for us, her greatest achievement is her legacy.

Catherine McKee, Blue Stocking Society, Friends' School, Lisburn, Co Antrim

What the judges say: 'Unusual subject, written in a controlled but passionate tone. A writer who loves her subject'