The hard problem of consciousness has puzzled philosophers and neuroscientists alike for decades. Here a philosopher, Riccardo Manzotti, and a neuroscientist, Anil Seth, meet to discuss consciousness, the hallucination of reality, and whether consciousness is inside or outside the brain.

I met Anil Seth many years ago. I think it was 2003, give or take. We had the first of many discussions about the nature of conscious experience. Although we share many ideas, we are also very different in the conclusions we draw. He takes consciousness to be an emergent phenomenon taking place inside the brain and I take consciousness to be the external world impinging on the brain. He believes that perception is a reliable hallucination, I believe hallucinations are a form of perception. This shows the richness of scientific debates on controversial topics such as consciousness, where scientists with different approaches and insights can benefit from a candid discussion. It is common knowledge that consciousness is still a great mystery to science and that although there has been a tremendous growth in scientific work on consciousness in the last decade, there is still no accepted theory on how consciousness arises in the physical world.