The United Nations University (UNU) Symposium on Science and Praxis of Complexity, held in Montpellier (France) in 1984, brought together renowned names such as Prigogine, Boulding, Pribram, Luhmann, Morin, Le Moigne, Atlan, among others. It set up the first international event on the topic of complexity science, and was meant to explore the epistemic consequences of concepts such as non-linearity, self-organization and emergence in systems composed by many interacting parts.
This watershed event was echoed, in the same year, by the creation of the Santa Fe Institute in the United States, which focused on many of the same themes: cross-disciplinarity, complexity, emergence. It constitutes the first interdisciplinary centre exclusively devoted to the study of complex systems.
Interestingly, many UNU conference participants and founding members of the Santa Fe Institute diverged in their approach to complexity. For Edgar Morin and Jean-Louis Le Moigne, for instance, complexity was linked to the problem of uncertainty in knowledge. It was mainly an epistemological position aimed at overcoming the traditional disjunction in knowledge between the subject of knowledge (the observer) and its object (the observed). The split was at the foundation of classical science, but it was also at the origin of its deterministic, reductionist and abstract principles; moreover, what they called the “paradigm shift” of complexity was loaded with social and ethical implications (The Science and Praxis of Complexity. Contributions to the Symposium Held at Montpellier, France, 9-11 May, 1984, The United Nations University, 1985; MORIN, Edgar, La Méthode, 6 vols, Seuil, Paris). For the founders of the Santa Fe institute, such as Murray Gell-Mann or John Holland, complexity was mainly "the science of complex adaptive systems". This definition delimited a field of science relying on computational tools to model systems containing multiple parts which are by their nature independent, highly interconnected, and interactive. Adaptive interactions of these parts elicit the emergence of structures and functions of self-organization, learning and evolution within the systems (COWAN, George A., PINES, David et MELTZER, David, Complexity: Metaphors, Models and Reality, Addison-Wesley, MA, 1994).
Moreover, if the UNU approach intended to bring together philosophy and science, complexity as envisaged by the Santa Fe Institute, conjured up neighbouring scientific fields such as physics, chemistry, biology, ecology, computer science or economy, in a common mathematical and formal framework. Since the 1990s, centres devoted to the study of complex adaptive systems have been spreading all over the world. The emergent dynamics of physical, biological, and social non linear systems are studied principally by means of agent-based modelling and simulation, including formalizations such as cellular automata, neural networks or genetic algorithms.
The shift in our definition of complexity is all the more appreciable if we compare today’s approach to those prevalent in the 1970s and 80s, more theoretical, epistemological, and philosophical. Twenty-five years after these pioneering experiences, our Symposium brings together these two approaches, namely “complex systems modelling” and “complexity thinking" in order to open a space of dialogue and communication.
Towards a new synthesis of divergent approaches to complexity
The Symposium on Complex Systems Modelling and Complexity Thinking arises from the ongoing and scientific exchange between the Edgar Morin Centre, EHESS, Paris, represented by his director, Claude Fischler, and University College London complexity researchers, represented by Sylvia B. Nagl (Head of the Cancer Systems Science Group at the Cancer Institute) and Robert Biel (member of the Development Planning Unit). The main purpose of this dialogue is to contribute to the launching of a forum of discussion and a research platform, ideally combining scientific and philosophical approaches exploring the full implications of the field of complexity. The current separation between complex systems modelling and complexity thinking calls for such a new opportunity for confluence, crossing disciplinary boundaries and bringing together philosophy and science, epistemology and computational modelling.
The question arises as to the inevitable antagonism, underlined by Edgar Morin, between both approaches to complexity. Despite their current mutual ignorance, our purpose will be to highlight possible links and bridges between them. Moreover, we are interested in detecting the signals for an upcoming confluence: the modellers seem in fact to become more and more interested in the epistemological aspects of complexity thinking; at the same time complexity thinkers realise they are found wanting of empirical methodologies. Notable antecedents for such a confluence can be founded in Atlan’s simulations of probabilistic automata networks, in the autopoietic model developed by Varela and Maturana, or in Denis Noble and Steven Rose’s peculiar crossover of science and philosophy (ATLAN, Henri, Entre le cristal et la fumée, Seuil, Paris, 1979 ; MATURANA, Humberto, and VARELA, Francisco, Autopoietic Systems, Universidad de Chile, 1972; NOBLE, Denis, The Music of Life. Biology Beyond the Genome, Oxford University Press, 2006; KAMIN, Leon, LEWONTIN, Richard, and ROSE, Steven, Not in Our Genes. Biology, Ideology, and Human Nature, Pantheon, New York 1985).
Our final goal is therefore to suggest the possible link of complexity thinking, in its philosophical and epistemological sense, and the "new kind of science" (as named by Stephen Wolfram) of complex adaptive systems modelling.