My mum always said the happiest time of her life was when she was the manageress of a shop in the east end.

She loved it, she earned her own money and was totally independent.

We can’t imagine it now, but when she got married she had to give up working, in those days it was seen as taking a job away from a man with a family to support.

So Mum became a housewife, and each week Dad would give her housekeeping money.

That was exactly the same as every other working-class family, it was the man’s job to work to provide the money and the woman’s job to keep the house clean and make sure there was hot food on the table.

That was the way the typical household worked, man: wage-earner, woman: housewife.

According to Marx, who got the idea from Hegel, we can see it as two opposites each of which creates and balances the other.

Marx got part of his philosophy from Hegel’s ‘master/slave’ example, as did Sartre later.

Very roughly, for Hegel, Marx, and Sartre, the ‘slave’ is as complicit in the relationship as the ‘master’ is.

Both need the other for there to be a relationship, without a slave, there can’t be a master.

Of course, no one realises they are agreeing to this, no one does it voluntarily.

Everyone accepts it only because they are born into it, it’s just the way the world works.

This is why one line of Mary Wollstonecraft’s has always reverberated in my head.

Around 1780, she wrote “Man will not be free until woman is free”.

She was introducing what has come to be known as ‘the Hegelian Dialectic of History’.

But she was saying it long before Hegel did.

In the same way as the ‘slave’ keeps the so-called ‘master’ imprisoned in his role, the role of the woman keeps the man imprisoned in his role.

The fact that each is forced to play a role means each is not really alive, according to Sartre, they are living ‘inauthentically’, living ‘in bad faith’.

According to Sartre, we cannot be truly alive until we become our true selves and stop merely playing a role.

Looked at that way, men and women couldn’t really be alive until they stopped playing the roles of housewives and wage earners.

In those roles men had to act as strong, hard-working, unemotional, the boss.

Women had to act as cooks, mothers, housekeepers, subservient.

So keeping women imprisoned in their role kept men imprisoned in their role.

This is what Mary Wollstonecraft meant by, “Man will not be free until woman is free”.

So the point isn’t for men to free women for the sole benefit of women.

The point is for men to free women for the benefit of men.

Mary Wollstonecraft saw that before Hegel, before Marx, before Sartre saw it.

If they don’t want to be imprisoned roleplaying the master, they have to stop women being imprisoned in the role of slave.

Simply by freeing woman from her burden, man frees himself from his burden.

Mary Wollstonecraft is using the purest, oldest advertising psychology.

The main question that makes any transaction successful is the answer to the question, “What’s in it for me?”

Whether we want people to buy something, vote a certain way, do (or stop doing) something, the ultimate question always is “What’s in it for me?”

Once we get past all the complicated marketing strategies, that’s what it comes down to.

Which is the sheer brilliance of Mary Wollestoncraft’s line, “Man will not be free until woman is free”.

Men shouldn’t make women free as a gesture of charity towards women, think of it from a merely selfish point of view.

What’s in it for you is that you get to be free, that’s what’s in it for you.