It turns out that much of what we do – much of our behaviour – can be conducted at an unconscious level. That raises a profound question. What is the point of consciousness? What evolutionary advantage does consciousness bestow? We speak to psychologists and neuroscientists for the answer. And we ask a philosopher whether science can ever unravel the deep mysteries of consciousness. The programme is guaranteed to hurt your brain. Presenter and producer David Edmonds Editor: Richard Knight (Photo: X-ray image of human head with lightning / Credit: Stock Photo. Getty Images)