Professor George Ellis and Tim Freke discuss whether some things are ‘evil as a matter of fact, the reality of ’downward causation’ and why determinism is wrong, whether numbers exist in an eternal Platonic realm, and what give meaning to life

George Ellis is Emeritus Professor in the Mathematics Department at the University of Cape Town, and visiting Professor in the Physics Department, University of Oxford. He is considered one of the world’s leading theorists in cosmology. He is an active Quaker and in 2004 he won the Templeton Prize. On 18 May 2007, he was elected a Fellow of the British Royal Society. He co-authored, with Stephen Hawking, The Large Scale Structure of Space-Time (Cambridge, 1975). He has been awarded the Star of South Africa Medal by President Nelson Mandela