Online research in philosophy

We examine cases of emergent behavior in physics, and argue for an account of emergence based on features of the phase space portraits of certain dynamical systems. On our account, the phase space portraits of systems displaying emergent behavior are topologically inequivalent to those of the systems from which they ‘emerge’. This account gives us an objective sense in which emergent phenomena are qualitatively novel, without involving the difficulties associated with downward causation and the like. We also argue that the role of complexity in emergence has been overstated: emergent behavior can occur in very simple systems, and even when it occurs in complex systems it is the qualitative novelty of that behavior, rather that the complexity of the system, that matters for emergence.

Psychoneural reduction is under attack again, only this time from a former ally: cognitive neuroscience. It has become popular to think of the brain as a complex system whose theoretically important properties emerge from dynamic, non-linear interactions between its component parts. ``Emergence'' is supposed to replace reduction: the latter is thought to be incapable of explaining the brain qua complex system. Rather than engage this issue at the level of theories of reduction versus theories of emergence, I here emphasize a role that reductionism plays – and will continue to play – even if neuroscience adopts this ``complex systems'' view. In detailed investigations into the function of complex neural circuits, certain questions can only be addressed by moving down levels and scales. This role for reduction also finds a place for approaches that dominate mainstream neuroscience, like the widespread use of experimental techniques and theories from molecular biology and biochemistry. These are difficult to reconcile with the anti-reductionist sentiments of the ``complex systems'' branch of cognitive neuroscience.

The concept of contextual emergence has been introduced as a speci?c kind of emergence in which some, but not all of the conditions for a higher-level phenomenon exist at a lower level. Further conditions exist in contingent contexts that provide stability conditions at the lower level, which in turn accord the emergence of novelty at the higher level. The purpose of the present paper is to propose that (proto-) consciousness is a contextually emergent property of self-sustaining systems. The core assumption is that living organisms constitute self-sustaining embodiments of the contingent contexts that accord their emergence. We propose that the emergence of such systems constitutes the emergence of content-bearing systems because the lower-level processes of such systems give rise to and sustain the macro-level whole (i.e., body) in which they are nested, while the emergent macro-level whole constitutes the context in which the lower- level processes can be for something (i.e., be functional). Such embodied functionality is necessarily and naturally about the contexts that it has embodied. It is this notion of self- sustaining embodied aboutness that we propose to represent a type of content capable of evolving into consciousness.

Strong claims have been made for emergence as a new paradigm for understanding science, consciousness, and religion. Tracing the past history and current definitions of the concept, Clayton assesses the case for emergent phenomena in the natural world and their significance for philosophy and theology. Complex emergent phenomena require irreducible levels of explanation in physics, chemistry and biology. This pattern of emergence suggests a new approach to the problem of consciousness, which is neither reducible to brain states nor proof of a mental substance or soul. Although emergence does not entail classical theism, it is compatible with a variety of religious positions. Clayton concludes with a defence of emergentist panentheism and a Christian constructive theology consistent with the new sciences of emergence.

Mental representations are based upon categories in which the state of a mental system is stable. Acategorial states, on the other hand, are distinguished by unstable behavior. A refined and compact terminology for the description of categorial and acategorial mental states and their stability properties is introduced within the framework of the theory of dynamical systems. The relevant concepts are illustrated by selected empirical observations in cognitive neuroscience. Alterations of the category of the first person singular and features of creative activity will be discussed as examples for the phenomenology of acategorial states.

More than thirty years ago, Amari and colleagues proposed a statistical framework for identifying structurally stable macrostates of neural networks from observations of their microstates. We compare their stochastic stability criterion with a deterministic stability criterion based on the ergodic theory of dynamical systems, recently proposed for the scheme of contextual emergence and applied to particular inter-level relations in neuroscience. Stochastic and deterministic..

The role of contingent contexts in formulating relations between properties of systems at different descriptive levels is addressed. Based on the distinction between necessary and sufficient conditions for interlevel relations, a comprehensive classification of such relations is proposed, providing a transparent conceptual framework for discussing particular versions of reduction, emergence, and supervenience. One of these versions, contextual emergence, is demonstrated using two physical examples: molecular structure and chirality, and thermal equilibrium and temperature. The concept of stability is emphasized as a basic guiding principle of contextual property emergence.

The role of contingent contexts in formulating relations between properties of systems at different descriptive levels is addressed. Based on the distinction between necessary and sufficient conditions for interlevel relations, a compre- hensive classification of such relations is proposed, providing a transparent con- ceptual framework for discussing particular versions of reduction, emergence, and supervenience. One of these versions, contextual emergence, is demonstrated using two physical examples: molecular structure and chirality, and thermal equilibrium and temperature. The concept of stability is emphasized as a basic guiding principle of contextual property emergence.

The emergence of mental states from neural states by partitioning the neural phase space is analyzed in terms of symbolic dynamics. Well-defined mental states provide contexts inducing a criterion of structural stability for the neurodynamics that can be implemented by particular partitions. This leads to distinguished subshifts of finite type that are either cyclic or irreducible. Cyclic shifts correspond to asymptotically stable fixed points or limit tori whereas irreducible shifts are obtained from generating partitions of mixing hyperbolic systems. These stability criteria are applied to the discussion of neural correlates of consiousness, to the definition of macroscopic neural states, and to aspects of the symbol grounding problem. In particular, it is shown that compatible mental descriptions, topologically equivalent to the neurodynamical description, emerge if the partition of the neural phase space is generating. If this is not the case, mental descriptions are incompatible or complementary. Consequences of this result for an integration or unification of cognitive science or psychology, respectively, will be indicated.

The concept of contextual emergence is proposed as a non-reductive, yet welldefined relation between different levels of description of physical and other systems. It is illustrated for the transition from statistical mechanics to thermodynamical properties such as temperature. Stability conditions are crucial for a rigorous implementation of contingent contexts that are required to understand temperature as an emergent property. It is proposed that such stability conditions are meaningful for contextual emergence beyond physics as well.