There have been several recent, high-profile controversies about artists' depictions of the child nude.
In our contemporary, western societies, it seems that pictures of children scare us more than any other possible subject for art.
But the child nude has been with us since antiquity, so is this predominantly a 21st-century obsession?
Laura Cumming explores the history of the child nude through a range of art works from antiquity to the present day.
Along the way, she consider works by Michelangelo, Caravaggio, Lewis Carroll, Balthus, Tierney Gearon and Nan Goldin, amongst others.
She examines what we can learn from these images about our changing attitudes to childhood, to censorship and to art.
How do we square our desire to protect children from exploitation with our belief in freedom of expression?