Melvyn Bragg and guests discuss the mind/body problem in philosophy. At the start of René Descartes' Sixth Meditation he writes: "there is a great difference between mind and body, inasmuch as body is by nature always divisible, and mind is entirely indivisible. For when I consider the mind, or myself in so far as I am merely a thinking thing, I am unable to distinguish many parts within myself; I understand myself to be something quite single and complete. Although the whole mind seems to be united to the whole body, I recognize that if a foot or an arm or any other part of the body is cut off nothing has thereby been taken away from the mind".This thinking is the basis of what's known as 'Cartesian dualism', Descartes' attempt to address one of the central questions in philosophy, the mind/body problem: is the mind part of the body, or the body part of the mind? If they are distinct, then how do they interact? And which of the two is in charge?With Anthony Grayling, Reader in Philosophy at Birkbeck, University of London; Julian Baggini, editor of The Philosophers' Magazine; Sue James, Professor of Philosophy at Birkbeck, University of London.