Books inspire us.
They teach us.
They let us escape into new worlds.
But some books do much more than this.
These books hit a collective nerve,
and have had a profound and lasting effect on society.
What are the titles that had this impact?
There are many, many books that fit this definition,
but we've managed to narrow it down to five books
that have truly shaped our world.
...wrote Robert Burton in his enormous 900 page book,
The Anatomy of Melancholy.
Which was first published way back in 1621.
So in the 17th Century,
there weren't books about melancholy,
or as we would call it today, depression.
It looks as if Robert Burton himself suffered from depression.
And there's a real sense
as he writes it, that he's writing himself into a position
of expertise about depression, so he can help himself
as well as other people.
And it's remained such a kind of influential book
over the centuries since then.
Not simply because of its subject matter,
it's the way it's written - it explores inner life
in a way that hadn't really been explored before.
So it's the patient's voice.
And one of the things that we've learnt over the last 20 years
is the importance of the patient's voice,
in targeting research and clinical treatment.
To 1960s America now,
where many people still thought that a woman's place was in the home.
Betty Friedan wrote The Feminine Mystique in 1963,
and in the introduction describes it as,
"The problem that has no name."
It was a book writing about the experience and aspirations
of women in suburban America.
It stood out as a book at this time because the experience of women
wasn't being written about in this way for the general population.
It stood out because she was standing up and saying,
"We need to acknowledge that there is more to life for these women
than being the perfect wife, the perfect mother."
She developed the idea that women needed to become politicised,
they needed to think about their experience at home.
However, and there is a big however,
the biggest criticism came from her exclusion of women of colour.
Poor women's experience was excluded, she also excluded lesbians.
Despite these shortcomings,
this book had real impact at the time.
It bought feminism to a very wide audience and that's a huge positive.
Bill McKibben's 1989 book, The End of Nature,
is considered to be the first book to bring global warming
to a general audience.
The End of Nature is about how humans are changing the planet.
It's a sad lament on human destruction.
In the 1980s, people had been talking about global warming,
but it hadn't entered the public consciousness as something
that we should be really concerned about,
and we should be already acting on.
What he did with this book is really wake people up
to this dramatic change that we are having globally on the natural world.
And which now is taken for granted by everybody,
we all are very aware of the impact we're having.
And it's largely due to books like this.
Things Fall Apart by Nigerian author Chinua Achebe,
was one of the first African novels in English
to gain global recognition and acclaim,
and it is still read and studied all over the world to this day.
Africa was always seen through the eyes of the white colonials.
It was like a door opening
into a world that white Europeans never understood
and even as it was published
people were astonished by the beauty of the book.
Here comes a man who's talking about Igbo villages in Nigeria
and their lives and their inner thoughts
and their hopes and desires and we'd never seen that.
And for Africans - and that's the more important point -
there were emerging writers,
they knew their time was now,
they knew that the world was ready
and it was that book that convinced them that it was.
And finally, to post-war Britain,
a time when many items were still rationed,
and to Elizabeth David's A Book of Mediterranean Food.
Britain already had a reputation for poor food,
plain food, grey food.
She wrote it as a memoir almost, of her time spent in southern Europe
before and during World War Two.
She wrote it really as a yearning for these wonderful places
and the colours and the scents and the flavours.
These days we completely take for granted ingredients like chickpeas,
lemon, garlic, olive oil, tomatoes, basil.
But then, when this book was published,
none of those ingredients were really available.
I mean, if you wanted to buy olive oil,
you had to go to a chemist's shop
because it was sold for treating earache.
She triggered a movement which we still feel today
which is one where food becomes something important
not just to our daily routine of nourishing ourselves
but saying a little bit more about who we are.
So there's now multiple generations
of food writers and cookery presenters
whose existence now would not have been possible without that book.
Words on a page can do so much more than entertain.
Some books have imagined, explored and introduced ideas
which have had a lasting impact on our society
which we experience to this day, even if we haven't read them.