Michael Sandel explores the philosophical justifications made for national borders. Using a pioneering state-of-the-art studio at the Harvard Business School, Prof Sandel is joined by 60 participants from over 30 countries in a truly global digital space.

Is there any moral distinction between a political refugee and an economic migrant? If people have the right to exit a country, why not a right to enter? Do nations have the right to protect the affluence of their citizens? And is there such a thing as a 'national identity'?

These are just some of the questions addressed by Prof Sandel in this first edition of The Global Philosopher.

Video editor: Chris Eyre

Audience producer: Louise Coletta

Producer: David Edmonds

Editor: Richard Knight