Melvyn is joined by four guests with different backgrounds to discuss a really big question. This week he's asking What makes us human?

Helping him answer it are philosopher Barry Smith, classicist Catharine Edwards, historian Simon Schaffer and theologian Giles Fraser.

For the rest of the week Barry, Catharine, Simon and Giles will take us further into the history of ideas about being human with programmes of their own. Between them they will examine the evolution of language, the Stoic philosopher Seneca, the classification of all living species, the philosopher Ludwig Wittgenstein and the film Bladerunner.