From day one we feel our way into, and through, the world.

By utlising a complex array of sensory receptors that grow and evolve as we mature, we come to understand not just everything we encounter in our external lives but also in our internal lives as well.

We are sentient beings.

But what is sentience and when did it arise in animals?

And why are we sentient at all?

Nicholas Humphrey is Emeritus Professor of Psychology at the London School of Economics. He is the author of many books on the evolution of human intelligence and consciousness, the latest being ‘Sentience: The Invention of Consciousness' - available in all good bookshops or online - he joins Jonathan to discuss.