How do I know that anybody else experiences the world in the way I do? Or even if other people experience anything at all? In the 20th century the philosopher Ludwig Wittgenstein responded to this challenge by thinking about whether we can make sense of the idea of a private language, a language understood only by the speaker. His so-called 'private language argument' has the potential to transform both the way philosophy is done, and the way we understand ourselves and our relationship with others.

Shahidha Bari is joined by the philosophers Stephen Mulhall and Denis McManus, and the historian and New Generation Thinker Tiffany Watt Smith.

You can find more discussions about philosophy on the Free Thinking website Philosophy playlist: https://www.bbc.co.uk/programmes/p07x0twx

Producer: Luke Mulhall