Complexity sciences have become famous worldwide thanks to several popular books that served as echo chambers of their promises. These consisted in departing from “classical science” defined as deterministic, reductionist, analytic and mono-disciplinary. Their founders and supporters declared that complexity sciences were going to give rise (or that they have given rise) to a post-Laplacian, antireductionist, holistic and interdisciplinary approach. By taking a closer look at their content and practices, I argue in this article that, because of their physics-oriented, computationalist, (...) and mathematical assumptions, complexity sciences have paradoxically produced knowledge at odds with these four tenets. (shrink)

We examine the phenomenon of emergence, referring particularly to Arthur Peacocke’s ideas on emergence, the self, and spirituality. He believes that the whole of an emergent structure influences the way its parts cohere and that emergent structures (including minds and persons) and their effects are very important. He thereby hopes to remove the reductionist challenge that seeks to understand a whole fully in terms of its parts. We argue that emergent phenomena are not influential in the above sense. The holistic (...) completeness of these structures at their own theoretical level does not substitute for the causal independence Peacocke suggests by the idea of influence. Some computer simulations that generate emergent complexity follow simple and self-contained sets of rules. Peacocke also adheres to a hierarchical account of reality as a series of levels into which matter is organized, running from atoms through molecules to cells and eventually to whole ecosystems. But influential behavior does not respect this ordering. Further, Peacocke’s opposition to reductionism is unnecessary; any “completeness‘ of lower-level models does not imply the redundancy of higher-level descriptions. Emergence transforms reductionism into a constructive and positive principle. (shrink)