A lawyer, artist and curator discuss different examples of censorship and self censorship in Radio 4's weekly discussion of ideas to kick off the week. Tom Sutcliffe's guests are:

Ai Weiwei: a major name in contemporary art and for decades a leading voice for freedom of expression in his native China – and the wider world. In 2011 he was detained for eighty-one days in a secret location, unable to communicate with the outside world. His new book, On Censorship moves from authoritarian regimes to the pervasive influence of corporate power, social media and dominant interest groups in democracies.

Baroness Helena Kennedy has written the introduction to collected writings of Anna Politkovskaya, the Russian journalist who was murdered outside her home in Moscow twenty years ago. With continued attacks in Russia on press freedom, the way she spoke truth to power remains inspirational for Baroness Kennedy.

The figure of the Samurai is often associated with ideas about discipline, sacrifice and war but a new exhibition at the British Museum (on until May 4th) looks at the way this warrior class became consumers and patrons of culture. Rosina Buckland has co-curated the show.

Producer: Ruth Watts