Physics underlies all complexity, including our own existence: how is this possible? How can our own lives emerge from interactions of electrons, protons, and neutrons? This book considers the interaction of physical and non-physical causation in complex systems such as living beings, and in particular in the human brain, relating this to the emergence of higher levels of complexity with real causal powers. In particular it explores the idea of top-down causation, which is the key effect allowing the emergence of true complexity and also enables the causal efficacy of non-physical entities, including the value of money, social conventions, and ethical choices.

George Ellis, FRS, is one of the world's leading researchers in general relativity theory and cosmology. He is Emeritus Distinguished Professor of Complex Systems in the Department of Mathematics and Applied Mathematics at the University of Cape Town in South Africa. He co-authored The Large Scale Structure of Space-Time with Cambridge physicist Stephen Hawking.

Complexity and Emergence.- Digital Computer Systems.- The Basis of Complexity.- Different Kinds of Top-Down Effects.- Room at the Bottom?.- The Foundations: Physics and Top-Down Causation.- The Mind and the Brain.- The Broader View.