Author: BBC Radio 4

What is art - and why do we need it?

Fifty years ago the landmark BBC Two series Civilisation set out to answer this question. Now historians Mary Beard, Simon Schama and David Olusoga take on this challenge of defining human civilisation through art, in a bold update renamed Civilisations. Mary Beard tells Andrew Marr how humans have chosen to depict themselves, from enormous pre-historic heads in Mexico to lustful paintings meant for male eyes. She unpicks the bloody battle between religion and art, and declares that "one man's art is another's barbarity".

But should art make us recoil? Simon Schama explores our urge to destroy the images we dislike, and finds that hatred and destruction have followed art through the centuries.

This clash of religions and cultures has enriched art, argues David Olusoga. He sees culture on the frontline as empires expanded and a battle took place to define what art could be.

This spring the artist Tacita Dean offers her own account of art's value and meaning as she unveils three exhibitions at once: exploring landscapes at the Royal Academy, portraits at the National Portrait Gallery and still life at the National Gallery. Moving between film and painted images, she challenges our idea of what art looks like.

Producer: Hannah Sander.

Brain damage can radically change a person's character - but does that mean they are no longer themselves?

Consultant neurologist Jules Montague works with people suffering dementia and brain injuries. She tells Tom Sutcliffe what happens when the brain misbehaves. Memories may fade and names disappear - but does that mean a person no longer has the same identity?

Behavioural scientist Nick Chater is sceptical about whether we have an inner self at all. His book The Mind is Flat exposes what he calls the 'shocking shallowness' of our psychology, and argues that we have no mental depths to plumb. Only by understanding this can we hope to understand ourselves.

The problem of self-awareness challenges psychiatrists hoping to diagnose depression, schizophrenia and other mental illnesses. Neuropsychiatrist Anthony David explores self-reflection and the stigma of mental illness in a series of lectures at King's College, London.

And fear of the mind runs through Ingmar Bergman's classic film Fanny and Alexander, now staged as a play at the Old Vic, London. Stephen Beresford has adapted it, and explains how the clash between a stern stepfather and his imaginative stepson reveals our unease at the power of the mind.

Producer: Hannah Sander.

Brain damage can radically change a person's character - but does that mean they are no longer themselves?

Consultant neurologist Jules Montague works with people suffering dementia and brain injuries. She tells Tom Sutcliffe what happens when the brain misbehaves. Memories may fade and names disappear - but does that mean a person no longer has the same identity?

Behavioural scientist Nick Chater is sceptical about whether we have an inner self at all. His book The Mind is Flat exposes what he calls the 'shocking shallowness' of our psychology, and argues that we have no mental depths to plumb. Only by understanding this can we hope to understand ourselves.

The problem of self-awareness challenges psychiatrists hoping to diagnose depression, schizophrenia and other mental illnesses. Neuropsychiatrist Anthony David explores self-reflection and the stigma of mental illness in a series of lectures at King's College, London.

And fear of the mind runs through Ingmar Bergman's classic film Fanny and Alexander, now staged as a play at the Old Vic, London. Stephen Beresford has adapted it, and explains how the clash between a stern stepfather and his imaginative stepson reveals our unease at the power of the mind.

Producer: Hannah Sander.

Humanity is flourishing and the Enlightenment has worked, declares Steven Pinker. The Harvard psychologist has looked across health, prosperity, safety, peace and happiness, and sees signs that all are improving. He tells Andrew Marr how Enlightenment attitudes to reason and science have made this the best age in which to live. But Enlightenment values are under attack and Pinker calls for their vigorous defence.

Dutch philosopher Rob Riemen also sees humanism under threat from fascism, with its politics of resentment and hatred of the life of the mind. But can reason, beauty and justice combat this threat?

The neuroscientist Tali Sharot thinks reason and fear are not enough to make us change our minds. Only by understanding how the brain functions can we perfect the art of persuasion.

Producer: Hannah Sander.

Humanity is flourishing and the Enlightenment has worked, declares Steven Pinker. The Harvard psychologist has looked across health, prosperity, safety, peace and happiness, and sees signs that all are improving. He tells Andrew Marr how Enlightenment attitudes to reason and science have made this the best age in which to live. But Enlightenment values are under attack and Pinker calls for their vigorous defence.

Dutch philosopher Rob Riemen also sees humanism under threat from fascism, with its politics of resentment and hatred of the life of the mind. But can reason, beauty and justice combat this threat?

The neuroscientist Tali Sharot thinks reason and fear are not enough to make us change our minds. Only by understanding how the brain functions can we perfect the art of persuasion.

Producer: Hannah Sander.

What would the perfect city look like?

Today more people live in cities than ever before and that shapes the way we think, says sociologist Richard Sennett. He lays out a vision for a city of the future based not on ancient Greece but on new 'open' streets.

Structural engineer Roma Agrawal charts the growth of cities from simple mud huts to the modern metropolis. She tells Amol Rajan about the engineering magic that holds towering city skylines in place, and recalls the eccentric engineers whose visions called our cities into being.

The Chinese built a city for the dead more than two thousand years ago and now its relics are on display again. Historian Edward Burman describes how the Terracotta Army found in a necropolis shows a ruler planning for life after death.

David Farr depicts the siege and destruction of Troy, the great city of the ancient world, in his vast new BBC One drama. He explains how the Trojans coped under ten long years of siege.

Producer: Hannah Sander.