Part Three. The essence of humanity is often considered to lie in the human mind. If we could grow a brain to put into an artificial being, would that make it human? Will it have a mind at all? Phil talks to Alan Jasanoff of the Massachusetts Institute of Technology (MIT) about the difficulties of understanding what the brain – and the mind – actually are. Thanks to Philip Ball for original music and www.Freesound.org for supplying sound effects under creative commons Attribution 3.0 license.