13 March 2009
Stuart Kauffman
Director of the Institute for Biocomplexity and Informatics, University of Calgary
External Professor, Santa Fe Institute
Visiting Professor, Harvard Divinity School
Since Descartes, Galileo, Newton, down to Einstein and Schrödinger we have believed that the unfolding of the universe is fully describable by natural law. We all know Laplace's Demon: given the positions and momenta of all the particles in the universe, the Demon could, using Newton's laws, deduce the entire future and past of the universe. This is the simplest statement of reductionism. It has at least four features: (i) the universe is deterministic; (ii) All that happens is describable by sufficient natural law; (iii) all that is "real" in the universe are particles in motion; (iv) there exists at least one language, here Newton's and particles in the void, sufficient to describe all of reality. Quantum mechanics leads to doubts about the first claim on the Copenhangen interpretation and the Born rule. The most radical claims I will make are that (ii), and (iii) are almost certainly false. In particular, the evolution of the biosphere, economy, and culture by Darwinian exaptations cannot be described by sufficient law. Nor can we make probability statements about such exapations. This, if true, implies that reductionism is inadequate by itself and that we live in an open universe, upward in complexity, open in the conditions for existence of organisms whose existence is not entailed, hence not explained, by reduction to physics. We need to invent a post-reductionist science. More, because we often do not know what CAN happen, reason alone, the highest human virtue of the Enlightenment, is an insufficient guide to living our lives. We need, I think, a new Enlightenment.