Reduction and Emergence in Science
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Program

CAS Schwerpunkt LogoLocation:
Center for Advanced Studies
Seestraße 13

 

Wednesday, 13 November, 19:00h:
Stephan Hartmann, Sebastian Lutz and Karim Thébault: Reduction and Emergence in Physics. Introductory talk for a general audience.

Thursday, 14 November
TimeTopic
09:00-10:00 Registration
10:00-10:10 Welcome
10:10-11:25 Keynote address
Margaret Morrison: The Physics of Ontological Emergence
11:25-11:55 Coffee
11:55-12:40 Alexander S. Blum and Christian Joas: From Dressed Electrons to Quasiparticles: The Emergence of Emergent Entities in Quantum Field Theory
12:40-13:50 Lunch
13:50-14:35 Wouter D'Hooghe and Sander Beckers: Dual Inheritance Theory as an Integration of Biology and the Humanities
14:40-15:25 Bert Baumgaertner and James Overton: Agent-based Models, Reduction, and Emergence
15:25-15:55 Coffee
15:55-16:40 Stefan Heidl: Intertheoretic Relations Between Economics and Psychology. The Case of Prospect Theory
16:45-18:00 Keynote address
Kevin D. Hoover: Reductionism in Economics: Causality and Intentionality in the Microfoundations of Macroeconomics
18:00 Reception

 

Friday, 15 November
TimeTopic
09:00-09:45 Elanor Taylor: An Explication of Emergence
09:50-10:35 Alexandru Manafu: Inter-theoretic Relations: the Brønsted-Lowry Theory of Acids and Microphysics
10:35-11:05 Coffee
11:05-11:50 Samuel Fletcher: The Topology of Intertheoretic Reduction
11:55-12:40 Joshua Rosaler: Reduction and Emergence in Physics: a Dynamical Systems Approach
12:40-13:50 Lunch
13:50-14:35 Karen Crowther: Novelty and Autonomy as Alternatives to, or Bases for, a Conception of Emergence in Physics
14:40-15:25 Sebastian de Haro, Dennis Dieks and Jeroen van Dongen: Reduction and Emergence in Holographic Scenarios for Quantum Gravity
15:25-15:55 Coffee
15:55-16:40 Ronnie Hermens: Reversed Reduction in Gibbsian Statistical Mechanics
16:45-18:00 Keynote address
Andreas Hüttemann: Failures of Reduction in Physics and Biology
 
19:00 Dinner

 

Saturday, 16 November
TimeTopic
09:00-09:45 Sebastian Lutz: Technical Aspects of Reduction and Non-Reductive Physicalism
09:50-10:35 Thomas Müller: How Can One and the Same Thing be Subject to Different Theories?
 On the Proper Logic for Non-Reductive Monism
10:35-11:05 Coffee
11:05-11:50 Frederik Willemarck: Heterogeneity and Emergence in the Social Sciences
11:55-12:40 Aziz F. Zambak: Synthetic Plasticity as a Computational Model of Emergence
12:40-13:50 Lunch
13:50-14:35 Marko Zivkovic: Scarecrow’s Brain and Homunculi: Neurobiological Reductionism as Ensoulment-Objectification Process Seen Through Anthropological Lenses
14:40-15:25 Peter Wyss: Emergence and Explanation
15:25-15:55 Coffee
15:55-17:10 Keynote address
Patricia S. Churchland: Cross-level Linkages in Neurobiology: Reductive Progress with Multiple Techniques

Abstracts

Bert Baumgaertner and James Overton: Agent-based Models, Reduction, and Emergence

We argue that agent-based models (ABMs) are better conceived of as multi- or intra-level models. Consequently, they are neither reductionistic nor emergent in the explanations they provide. We argue for this by first contrasting them with analytical models, which tend to focus on macro-level entities or properties. We then use an example of an ABM of group-selection from the biological sciences which is thought to be purely individualistic. However, we argue that the model is misconceived. The macro-level properties required to make the model work are not straightforwardly given by the composition of the individuals in the group.

Alexander S. Blum and Christian Joas: From Dressed Electrons to Quasiparticles: The Emergence of Emergent Entities in Quantum Field Theory

The development of renormalization group techniques and effective field theories in the 1970s have led to a major reinterpretation of the renormalization program originally formulated in the late 1940s within quantum electrodynamics (QED). A more gradual shift in its interpretation, however, occurred already in the early-to-mid-1950s when renormalization techniques were transferred to solid-state and nuclear physics and gave rise to the notion of effective or quasi-particles, emergent entities that are not to be found in the original, microscopic description of the theory. We study how the methods of QED, when applied in different contexts, gave rise to this ontological reinterpretation.

Patricia S. Churchland: Cross-level Linkages in Neurobiology: Reductive Progress with Multiple Techniques

In neurobiology, an important strategy is to link high level properties, such as spatial knowledge or impulse control, to specific macro structuresand to signature neuronal activity in parts of those structures. At a deeper level, the goal is to understand that neuronal signature in the context of regional microanatomy, neuropharmacology, and basic neuronal physiology. Where possible, the companion goal is to link the structural changes during learning to gene expression. In some conditions, such as Williams syndrome, the deficits can be linked to deletion of specific genes that alter brain development. Thus techniques ranging from genetics to cellular recording to imaging to behavioral analysis are used to converge on a function with a view to explaining its neurobiological basis.

Karen Crowther: Novelty and Autonomy as Alternatives to, or Bases for, a Conception of Emergence in Physics

An effective theory in physics is one that is supposed to apply only at a given length (or energy) scale; the framework of effective field theory (EFT) describes a ‘tower’ of theories each applying at different length scales, where each ‘level’ up is a shorter-scale theory. A subtlety regarding the use and necessity of EFTs means that any conception of emergence related to reduction is irrelevant, failing to capture the relations of interest in these real physical cases. A positive conception of emergence, based on the novelty and autonomy of the ‘levels’, is developed by considering other physical examples, including critical phenomena, symmetry-breaking and hydrodynamics, in addition to EFT more generally.

Sebastian de Haro, Dennis Dieks and Jeroen van Dongen: Reduction and Emergence in Holographic Scenarios for Quantum Gravity

‘Holographic’ relations between theories have become a main theme in quantum gravity research: a theory without gravity is in some way equivalent to a gravitational theory with an extra dimension. ‘t Hooft first proposed holography for evaporating black holes in 1993, “AdS/CFT” duality is a more recent holographic topic of study. Very recently, Verlinde has proposed that even Newton’s law of gravitation can be related holographically to a thermodynamics of information on screens. We discuss theory reduction and spacetime emergence in these scenarios: in what sense are these theories equivalent or reduce to each other and when is spacetime emergent?

Wouter D'Hooghe and Sander Beckers: Dual Inheritance Theory as an Integration of Biology and the Humanities

Proponents of Dual Inheritance Theory (DIT) claim that it can unify the human sciences. This claim has come under attack by social scientists, as it is taken to imply a reduction of the humanities to cultural evolution. We argue that although unification is indeed an overstretch, DIT can serve to synthesize different disciplines in a more modest sense: it can provide an integration of biology and the humanities. We explicate the difference between these two alternatives by defining the concepts of unification and integration, and specify how DIT can fulfill this ambition concretely.

Samuel Fletcher: The Topology of Intertheoretic Reduction

The standard accounts of reductive limiting relations between theories tend to focus on the limits of particular laws instead of limits of models. To bring limiting relations in line with the modern semantical view of theories, I propose topologizing the space of models of a potential reductive theory pair. I stress that justifying why a particular topology is appropriate for a given reduction relation is crucial, as it may perform much of the work in demonstrating a particular reduction’s success or failure. To illustrate, I consider the reduction of general relativity to (geometrized) Newtonian gravitation.

Stefan Heidl: Intertheoretic Relations Between Economics and Psychology. The Case of Prospect Theory

Abstract: In my paper I analyze intertheoretic relations between economics and psychology. I present a case study from the economic sub-discipline of behavioral economics. Behavioral economists try to integrate results of cognitive and social psychology into economic theory.
I argue that behavioral economists integrate psychological theory into economics by the creation of hybrid theories. Such hybrid theories keep the basic structure of standard economic decision theory but include additional variables to model psychological properties of the choice process from which standard economics abstracts. These properties are identified identified with the help of psychological theories and experiments.

Ronnie Hermens: Reversed Reduction in Gibbsian Statistical Mechanics

Statistical mechanics is the branch of physics which uses probability theory to describe and explain the macroscopic behavior of many particle systems in terms of the mechanical behavior of their constituents. Part of this macroscopic behavior is independently captured by thermodynamics. In this talk I will lay out some difficulties with the purported reduction of thermodynamics to Gibbsian statistical mechanics. The explanatory power of the use of probabilities will be evaluated with respect to the interpretation of probability adopted. I will argue that a consistent reading of statistical mechanics requires that probabilities are motivated by thermodynamics rather than providing an explanation for it.

Kevin D. Hoover: Reductionism in Economics: Causality and Intentionality in the Microfoundations of Macroeconomics

In many sciences—physical, but also biology, neuroscience, and other life sciences—one object of reductionism is to purge intentionality from the fundamental basis of both explanations and the explanatory target. The scientifically relevant level—ontologically and epistemologically—is thought to lie deeper than the level of ordinary human interactions. In the material and living world, the more familiar is the less fundamental. In contrast, the economic world of day-to-day life—the world of market interactions—appears to be the relevant level. Macroeconomics is thought to provide an account that is above, not below or behind, ordinary economic decision-making. An advantage of a macroeconomic account is that it is possible to employ causal analysis of the economy as a whole analogous to the causal analysis of physical systems. The fear of many economists is that such analyses are untethered to ordinary economic decision-making. The object of reductionism in economics—the so-called microfoundations of macroeconomics—is adequately to ground or replace higher level causal analysis with an analysis of the day-to-day interactions of people. The object is not to purge intentionality, but to reclaim it. The paper will attempt to understand the key issues surrounding the microfoundations of macroeconomics from a perspectival realist perspective that elucidates the relationship between economists’ methodological preference for microfoundations and need for macroeconomic analysis—that is, between economists’ respect for the intentional nature of economic life and the need for a causal analysis of the economy. The paper favors metaphysical humility and methodological pragmatism.

Andreas Hüttemann: Failures of Reduction in Physics and Biology

Sebastian Lutz: Technical Aspects of Reduction and Non-Reductive Physicalism

In my talk, I will suggest conceptualizations of reducibility, supervenience and non-reductive physicalism within type theory and model theory. The conception of reduction is Nagelian in spirit but logically significantly different, and one of the suggested conceptions of non-reductive physicalism captures Fodor’s claims about disjunctive properties without relying on his problematic assumptions about natural kinds.

Alexandru Manafu: Inter-theoretic Relations: the Brønsted-Lowry Theory of Acids and Microphysics

This paper examines the relations between the Brønsted-Lowry theory of acids and the underlying microphysical theories. It argues that these relations are complex and somewhat messy. They do not lend wholesale support to any of the philosophical theories of reduction or emergence. However, they do support particular aspects from both sides. The paper fleshes out what these aspects are, and draws some general philosophical lessons. One of these is that acidity is a sui generis chemical property, which is made possible by processes at the lower level, but which can be adequately defined only at a higher level.

Margaret Morrison: The Physics of Ontological Emergence

Emergent phenomena are typically described as those that cannot be reduced, explained nor predicted from their microphysical base. However, this characterization can be fully satisfied on purely epistemological grounds, leaving open the possibility that emergence may simply point to a gap in our knowledge of these phenomena. By contrast, Anderson’s (1972) claim that the whole in not only greater than but very “different from” its parts implies a strong ontological dimension to emergence, one that requires us to explain how macro properties characteristic of emergence can be ontologically distinct from the micro properties from which they emerge. This is partly explained by using RG methods to show how the ‘universal’ characteristics of emergent phenomena are insensitive to the Hamiltonian(s) governing the microphysics. But this is not wholly sufficient since it is possible to claim that the independence simply reflects the fact that different ‘levels’ are appropriate when explaining physical behavior, e.g. we needn’t appeal to micro properties in explaining the macro behavior of fluids. The paper attempts a resolution to the problem of ontological independence by showing how a closer examination of RG methods can provide a way of explicating the relation between micro and macro properties, a relation that satisfies the requirements for ontological emergence in physics.

Thomas Müller: How Can One and the Same Thing be Subject to Different Theories?
 On the Proper Logic for Non-Reductive Monism

The aim of this paper is to shed light on a neglected issue in the field of intertheoretic relations: How is it that properties belonging to different theories apply to one and the same thing? What does that teach us about the notion of being one and the same thing, and what could an adequate formal representation of sameness look like? What about the controversial thesis of constitution as identity that seems to be required for a monistic (e.g., physicalistic) metaphysics? By discussing a simple example—physical and biological properties applying to a cat—we argue that standard logical resources of predicate or quantified modal logic are inadequate for the task. We finally describe case-intensional first order logic, which provides an adequate formal framework for non-reductive monism.

Joshua Rosaler: Reduction and Emergence in Physics: A Dynamical Systems Approach

I elaborate an approach to reduction in physics that is distinct from the Nagelian and limit-based approaches that have been discussed most widely in the philosophical literature. This approach, which I call ‘Dynamical Systems (DS) Reduction’, is intended to apply to the reduction of theories whose models can be formulated as dynamical systems models. Importantly, this is the case with most physical theories, including classical mechanics, classical field theory, quantum mechanics and quantum field theory.

After setting out the basic elements of DS reduction, I compare this approach with the limit-based and Nagelian approaches, arguing in each case that the DS approach does better. In particular, I highlight a number of significant parallels between the DS and Nagelian approaches, specifically relating to their use of special correspondences between theories (what are most commonly called ‘bridge laws’ in Nagelian approaches) to identify those elements of the low-level theory that emulate the behavior of certain elements in the high-level theory. Despite these similarities, I argue that DS reduction, in its use such correspondences (which I call ‘bridge maps’) does not face the ambiguities or difficulties that are often associated with Nagelian bridge laws: in particular, I argue that it avoids ambiguities as to whether these correspondences are to be regarded as conventions or empirically substantive claims, as well addressing concerns about multiple realisability.

Elanor Taylor: An Explication of Emergence

There is a consensus in contemporary philosophy that debates about emergence are confused and messy. In this paper I offer a unified explication of emergence, and argue that this explication can cut through the confusion evident in discussions of emergence. I argue that the best way to understand the concept of emergence is as the unavailability of a certain kind of scientific explanation for an observer or observers. According to this perspectival account of emergence, emergence (the unavailability of a certain kind of scientific explanation for an observer or observers) can track a range of different metaphysical and epistemic relations.

Frederik Willemarck: Heterogeneity and Emergence in the Social Sciences

In my paper, I focus on the relationship between collective properties (pertaining to collectives) and individualistic properties (pertaining to individual persons) in the social sciences. I argue that there is a sub-class of collective properties—I call them heterogeneous (collective) properties—which fail to reduce to, and supervene on, individualistic properties. In addition, I also show that heterogeneous properties have real causal power, at least in the sense that they are capable of influencing events at the individualistic level. I thus conclude that heterogeneous properties should be interpreted as emergent properties in the social context.

Peter Wyss: Emergence and Explanation

The notion of emergence has acquired explanatory power in relation to the mind–body problem. It seems that we explain something when we say that consciousness emerges from brain function, or that mind emerges from matter. I criticise this (puzzling) intuition, and hence 'epistemic emergence'. I argue that 'explanations' in terms of emergence are incoherent at worst; and at best, they make explicit our ignorance. Some explanatory punch can be rescued only if emergence is ontologised. I sketch such an approach. Although more substantial than many of the current discussions, it gets an explanatory grip on two central features of emergence, viz. novelty and irreducibility.

Aziz F. Zambak: Synthetic Plasticity as a Computational Model of Emergence

Human mind and intelligence should be considered as open and plastic systems, which cannot be simulated and modeled by classical types of modeling; moreover, the human mind has its own capacity for self-organization, regulation, autonomy, adaptation, growth, and hierarchical organization. Cognition is, therefore, not the assemblage of cognitive skills and locations of the brain functioning independently of one another, but is its interacting and integrated structures. We claim that in a computational manner, these interacting and integrated structures of brain functioning is the source of the emergence of high-level cognitive skills and they can be understood in a synthetic plasticity model. In the paper, we will present the theoretical and methodological principles of the synthetic plasticity model for building a computational emergence approach to the high-level cognitive skills.

Marko Zivkovic: Scarecrow’s Brain and Homunculi: Neurobiological Reductionism as Ensoulment-Objectification Process Seen Through Anthropological Lenses

Using Scarecrow’s brain to think through folk psychology’s encounter with neurobiological reductionism, I will try to reframe the debates among Dennett, Bennet & Hacker, Searle and the Churchlands in terms of anthropological understandings of “folk psychology” developed by Alfred Gell, Gregory Schrempp’s mythological analysis of homunculism, and Michael Polanyi’s conceptualization of from-to nature of all knowing. My premise is that all the positions taken on the issue of neurobiological reduction are variants of ensoulment-objectification processes systematically examined in Gell’s distributed personality theory.