Principles of Systems and Cybernetics: an Evolutionary Perspective

Principles of Systems and Cybernetics: an evolutionary perspective Francis HEYLIGHEN* PO, Free University of Brussels, Pleinlaan 2, B-1050 Brussels, Belgium [email protected] ABSTRACT: A set of fundamental principles for the and definitions. The fundamental principles, like all good cybernetics domain is sketched, based on the axioms, are supposed to be self-evident, if not tautologous. spontaneous emergence of systems through variation and Their implications, like most theorems, on the other hand, selection. The (mostly self-evident) principles are: may be far from trivial, and sometimes even counter- selective retention, autocatalytic growth, asymmetric intuitive. transitions, blind variation, recursive systems This paper will propose a first, necessarily limited and construction, selective variety, requisite knowledge and sketchy, overview of the principles that I think are most incomplete knowledge. Existing systems principles, such basic, starting from the most primitive ones, and building up as self-organization, “the whole is more than the sum of towards less obvious ones. This overview is offered for its parts”, and order from noise can be reduced to discussion and elaboration by other systems researchers. A implications of these more primitive laws. Others, such more in-depth treatment of this issue is being prepared in the as the law of requisite variety, the 2nd law of form of a series of journal papers (Heylighen, forthcoming). thermodynamics, and the law of maximum entropy production are clarified, or restricted in their scope. 2 The Principle of Selective Retention 1 Introduction Stable configurations are retained, unstable ones are Principles or laws play the role of expressing the most eliminated. basic ideas in a science, establishing a framework or methodology for problem solving. The domain of This first principle is tautological in the sense that stability can be defined as that what does not (easily) change or General Systems and Cybernetics is in particular need of disappear. Instability then is, by negation, that what tends to such principles, since it purports to guide thought in vanish or to be replaced by some other configuration, stable general, not just in a specific discipline. Unfortunately, the few generally used principles of the domain, such as or unstable. The word “configuration” denotes any the law of requisite variety, or the principle that the phenomenon that can be distinguished. It includes everything that is called feature, property, state, pattern, whole is more than the sum of its parts, are typically structure or system. ambiguous or controversial, and lack coherence with each other. The principle can be interpreted as stating a basic distinction between stable configurations and configurations undergoing The present work purports to start a general examination of principles of cybernetics and systems, within the variation. This distinction has a role in evolution which is as framework of the Principia Cybernetica Project fundamental as that between A and not A in logic. Without negation, we cannot have a system of logic. Without (Heylighen, Joslyn & Turchin, 1991; Turchin, 1991). (in)stability we cannot describe evolution. The tautology The Principia Cybernetica philosophy is evolutionary: plays a role similar to the principle of contradiction: “A and systems and their cybernetical organization are not A cannot both be true”. The distinction between stable constructed through the self-organizing process of blind variation and natural selection. This process function as a and changing is not as absolute as that between A and not A, skeleton interconnecting all principles. though. We do not require a principle of the excluded middle, since it is clear that most configurations are neither The study will on the one hand critically assess existing absolutely stable nor absolutely unstable, but more or less principles, clarifying their meaning, on the other hand try stable. In this more general formulation, the principle would to formulate new principles which may generalize or read: interconnect known laws. The ultimate goal is to arrive at a network of concepts and principles similar to a More stable configurations are less easily eliminated than formal system, with “axioms” implicitly defining less stable ones primitive concepts, definitions of higher order concepts, and “theorems”, derived from the more primitive axioms 3 The Principle of Autocatalytic reachable states signifies that the variety, and hence the Growth statistical entropy, of the system diminishes. It is because of this increase in neguentropy or organization that Ashby calls Stable configurations that facilitate the appearance of the process self-organization. But how does this fit in with configurations similar to themselves will become more the 2nd law of thermodynamics, which states that entropy in numerous closed systems cannot decrease? The easy way out is to conclude that such a self-organizing system cannot be This self-evident principle is the companion of the closed, and must lose entropy to its environment (von principle of selective retention. Whereas the latter Foerster, 1960). expresses the conservative aspect of evolution, maintenance or survival, the former expresses the A deeper understanding can be reached by going back from progressive aspect, growth and development. the statistical definition of entropy to the thermodynamic Autocatalytic growth describes as well biological one, in terms of energy or heat. Energy is defined as the reproduction, as the positive feedback or non-linearity capacity to do work, and working means making changes, characterizing most inorganic processes of self- that is to say exerting variation. Hence energy can ve organization, such as crystal growth. The principle viewed as potential variation. A stable configuration does simply states that it suffices for a configuration to be not undergo variation. In order to destroy a stable stable, and in some respect autocatalytic or self- equilibrium, you need to add energy, and the more stable the replicating, in order to undergo a potentially explosive configuration, the more energy you will need. Therefore growth. stability is traditionally equated with minimal energy. Such configurations, in biology, are said to have a high The 1st law of thermodynamics states that energy is fitness and that gives them a selective advantage over conserved. A naive interpretation of that law would conclude configurations with a lower fitness. The fact that growth that the principle of asymmetric transitions cannot be valid, requires (finite) resources implies that growth must since it postulates a transition from an unstable (high energy) eventually stop, and that two configurations using the to a stable (low energy) configuration. If energy is same resources will come in competition for these absolutely conserved, then an unstable configuration can resources. Normally the fitter configuration will only be followed by another unstable configuration. This is outcompete the less fit one, so that no resources are left the picture used in classical mechanics, where evolution is for the latter (survival of the fittest). Such a reversible, that is to say symmetric. Incidentally, this shows generalization of the principle of selective retention may that the principle of asymmetric transitions is not be called the principle of natural selection. tautological - though it may appear self-evident - , since a perfectly consistent theory (classical mechanics) can be built on its negation. 4 The Principle of Asymmetric Transitions: entropy and energy Thermodynamics has enlarged that picture by allowing energy dissipation. But what happens with the “dissipated” A transition from an unstable configuration to a stable energy? A simple model is provided by a quantum system one is possible, but the converse is not. (e.g. an electron bound in an atom) with its set of - usually This principle implies a fundamental asymmetry in discrete - energy levels. A configuration at a higher level evolution: one direction of change (from unstable to will spontaneously fall down to a lower level, emitting a stable) is more likely than the opposite direction. The photon which carries the surplus energy away. In order to generalized, “continuous” version of the principle is the bring back the electron to its higher level, energy must be following: added by having a photon of the right energy and direction hit the electron, a rather improbable event. Hence, the low The probability of transition from a less stable level can be viewed as a stable configuration, with a small configuration A to a more stable one B is larger than the probability of transition. probability for the inverse transition: P (A -> B) > P (B - > A) (under the condition P (A -> B) =/ 0) The conjunction of energy conservation and asymmetric transitions implies that configurations will tend to dissipate A similar principle was proposed by Ashby in his energy (or heat) in order to move to a more stable state. For Principles of the Self-Organizing System (1962):”We a closed system, this is equivalent to the thermodynamical start with the fact that systems in general go to interpretation of the 2nd law, but not to the statistical one, as equilibrium. Now most of a system’s states are non- the statistical entropy can decrease when transition equilibrial [...] So in going from any state to one of the probabilities are asymmetric. In an open system, on the other equilibria, the system is going from a larger

Load more