Musings of the ASA Director Emeritus
Blog Home All Blogs
This blog compiles the occasional musings of Randy Isaac who was ASA Executive Director from 2005 to 2016 and is now ASA Director Emeritus.

 

Search all posts for:   

 

Top tags: Larson  On Faith and Science  Ruse  theistic evolution  evolution  Ellis  Emergence  Mind  Evolutionary Creation  information  concordism  faith  science  annual meeting  ASA  cosmological constants  cosmos  fine tuning  human evolution  Physics  Probabilities  2016  Ancestry  anthropocene  computers  Darwinism  Dictionary  Ellisretirement  fossils  genius 

draft of Ellis Book Review

Posted By Randall D. Isaac, Wednesday, November 23, 2016

I wish all of you a thoughtful and thankful holiday. If you need a break from family, fun, and food, I'd appreciate your taking a few moments to review the first draft of my attempt to take all those excerpts I've posted and construct a reasonable book review. The draft is posted here. I will keep it updated with changes as I edit it and then delete it and this post when I submit for publication. Please let me know what I left out, what I should leave out, and what needs clarification.

Thank you!

Tags:  Ellis  Emergence  Mind 

Share |
PermalinkComments (9)
 

Ellis--Chapter Eight: The Broader View

Posted By Randall D. Isaac, Friday, November 4, 2016

In this final chapter of the book, Ellis succinctly restates his views and admittedly embarks on a polemic for his world-view of emergence. He gives a practical example in the field of learning to read and write and lays out the path for more work to be done. The following excerpts give a hint as to the nature and tone of the book, which for me has been most compelling.

“The conclusion arising from the arguments given in this book is that there are other forms of causation than those encompassed by physics and physical chemistry alone, or even in genetics and neuroscience. Higher levels of structure have causal powers, based on strong emergence of higher level structure and function that can shape what happens in the world.”

“So from where do higher level ideas, theories, and behavior arise, given that they cannot be uniquely determined by physics data in the early universe? The obvious explanation is that they arise from the autonomous behavior of the human mind acting in an intelligent way, supervenient on but not causally determined by the underlying physics.”

“…emergence of higher level causal powers is possible because of randomness at lower levels that allows for selection of functionality on the basis of higher level selection criteria. And that is a form of top-down causation, adapting emergent life to its environment. There are essentially three ways that emergent properties come into being:

·       Self-assembly: emergence in the natural world

·       Natural selection: emergence in the biological world

·       Design and construction in the man-made world.”

 

“…while purely bottom-up effects can produce key ingredients needed for the existence of life, and while they can produce many interesting structures and patterns, what they can achieve is nevertheless strictly limited: it cannot lead to the existence of life. This needs the initiation of the top-down causal transfer of information that is required for adaptive selection to take place.”

“Chance, necessity, and purpose intertwine in the real world around us. Jacques Monod famously claimed that all that matters in biology is chance and necessity. But this misses the key element of purpose or goal-seeking, which is crucial to life.”

“That random processes are a core feature of biological functioning is indicated by many kinds of evidence…At the micro-level, biological systems do not live in a carefully controlled environment: they face rampant randomness all the time. It turns out that they take advantage of the storm of randomness encountered at the molecular level: there is much evidence that molecular machinery in biology is designed to use that randomness to attain its desired results…Randomness is harnessed through the process of adaptive selection, which allows higher levels of order and meaning to emerge. It is then a virtue, not a vice. It allows purpose to be an active agent by selecting desired outcomes from a range of possibilities.”

“[Physiological systems] came into being through natural selection, because they promoted survival. Once in existence, passed from generation to generation by genes and developed in each body by developmental processes, they have specific functions or purposes that are allowed by and indeed implemented through the underlying physics. But that physics knows nothing of these purposes.”

“Chance, necessity, and purpose all occur in living systems. It is the relation between them that is at issue, and this is where information comes in…And how does purpose fit in? An element of randomness at the bottom does not mean that all that happens is just pure chance. Rather it is one of the foundations that, together with necessity, opens up the possibilities of purposeful function and meaningful mental life, realized through physical existence. It does not have to have the connotation of meaningless so often ascribed to it. It is the gateway to variety and possibility.”

“Lower level random processes allow adaptive selection to work, creating purposeful order, on the basis of physical and chemical laws, embodying necessity. Physics provides the possibility space for what happens, but does not determine the outcome. Top-down causation allows higher level causes be what they appear to be: real effective causes that select lower level outcomes. Adaptive selection creates new classes of information and new instances of those classes, e.g., the genetic code and DNA that uses that code. Random fluctuations plus quantum uncertainty provide the freedom at the bottom needed to allow this to happen.”

“It is the existence of random processes at lower levels that enables purposeful actions at higher levels to take place through selection of preferred outcomes according to some higher level selection criterion. This enables processes of adaptation and learning in accordance with the logic of some higher level purpose.”

“Some aspects of complex systems are emergent from the interaction between the underlying particles and forces, but others are not emergent: rather they arise from the nature of the external environment. A crucial point then is that this environment includes abstract Platonic entities, such as mathematical forms and the laws of logic, which are not reducible to or emergent from any physical entities. They do, however, have causal power. They are transcendent entities in that they are timeless and universal, but not of a physical nature.”

“The issue is whether there is real emergence of higher levels, with genuine causal powers in their own right (‘strong emergence’) or whether the higher levels are epiphenomena, with no real power of their own: they are dancing to the tune of the lower levels.”

“The point then is that physics as it currently stands is causally incomplete. It is not able to describe all the causes and effects shaping what happens in the world…Physics at the micro-level has an irreducible random element. This allows higher level selection processes to select lower level outcomes to suit higher level function or purpose.”

“The view put forward in this book has substantial social implications. The bottom-up view of causation has pervaded much scientific thought in general, and so for example has been a major factor in medicine and psychiatry. In each of these areas there has in effect been a long-standing tension between bottom-up and top-down views with major implications for medical practice and effectiveness. The view implied by this book is that it is crucial that top-down effects be taken into account as a major influence, as well as bottom-up (molecular and gene-based) effects.”

One of the last sections in the book is written jointly with Ellis’s wife, Carole Bloch. It explores the implications of the views of this book on “Learning to Read and Write.” It elucidates the nature of bottom-up and top-down causality in field of oral and written language. Essentially, they argue the reading should not be taught bottom-up by first learning syllables and grammar but top-down by seeing the elements of written words in their meaningful context. The details can come later.

Ellis closes the book with this final paragraph: “The daily world in which we live came about by imaginative investigation of possibilities, discarding those that don’t work: the adaptive process that is a central theme of this book, enabled by a modicum of randomness at the macro- and micro-levels, interacting with necessary physical processes. And it is these processes that also allow the emergence of the ordinariness of everyday life: which actually is quite extraordinary. Bottom-up effects are crucial to emergence. Physics underlies all. Nevertheless, the vitality of life, which arises from physics, transcends it.”

Tags:  Ellis  Emergence  Mind 

Share |
PermalinkComments (3)
 

Ellis--Chapter Seven: The Mind and the Brain

Posted By Randall D. Isaac, Saturday, October 29, 2016

Finally we come to the penultimate chapter of the book and the primary aim of the book. How does all of this relate to the mind and the brain? Ellis says “The main claim will be that one cannot begin to understand the brain properly without taking top-down causation into account…This is top-down causation from the social milieu to detailed aspects of brain structure.” He intends to show that just as in all the other examples given in this book so far, the brain is a combination of bottom-up and top-down causation. In this way, “physics can underlie the extraordinary nature of the functioning of the mind.” He underscores however that he is not claiming to have solved the problems of free will or of consciousness but rather to have outlined critical features that any such approach must include.

His view of the organization of the brain is summarized in this table:

 

Ellis emphasizes the role that symbolism and language, purpose and meaning, and our system of values and ethics plays in affecting our brain which in turns affects our higher level decision process and actions. He also notes that “The mind can discover unchanging eternal relationships and possibilities that were always there and exist independently of the human mind: that is, they can reasonably be called Platonic entities.”

Ellis embarks on a detailed description of the biology of the brain. A key point that he makes is illustrated by his quote of Alwyn Scott discussing the Hodgkin-Hawley equations that describe action potential in neurons: “One cannot derive these laws from physics and chemistry because they depend upon the detailed organization of the intrinsic proteins that mediate sodium and potassium current across the membrane and upon the geometric structure of the nerve fibres.”

In other words, this is genuine emergence. The physics and chemistry of the atoms and molecules within the neuron is constrained or bounded by higher level parameters from the environment. This is a true top-down causality with the emergence of new features that require new equations to describe.

“A key question, of course, is how the brain gets to be what it is…The primary point is that the brain is not developed in a predetermined way through genetic influences: rather it adapts to the environment in which it finds itself. Brain plasticity at the micro-level allows adaptation at the macro-level. This development is guided by experience, evaluated on the basis of the primary emotional systems.”

“Minds cannot be understood on their own: we have a distributed cognition that is not contained solely within the head of the individual…The human mind is unlike any other on this planet, not because of its biology, which is not qualitatively unique, but because of its ability to generate and assimilate culture, which provides us with symbolic tools such as language that then shape the way we see reality.”

“David Sloan Wilson remarks that the transition from bottom-up to top-down dominated causation in the relation of mind to the society in which it is imbedded is a major evolutionary transition in the historical development of humanity, resulting in the emergence of the social order as a higher level entity in its own right, and a consequent change in the nature of the evolutionary processes at work.”

 

“Interlevel causation, both bottom-up and top-down, is key to brain function. Evolution has selected for it to occur. The underlying physics is channeled and constrained to enable this to happen.”

“…this process faces a problem of infinite recursion: where does the next higher level of selection criteria come from? At some point we have to draw a line and say, this is where I stand: these are my founding principles, this is the purpose in my life. That is where one makes value choices based on one’s view of meaning…These are abstract ideas that shape what one does, and thereby act down to muscles, neurons, and genes, and on to electrons and atoms as we try to fulfil these goals and purposes.”

“[Consciousness] is an emergent property of a dynamic core of neurons. It is a higher level process enabled by the properties of the underlying neurons and genes, in turn enabled by the properties of the underlying molecules and physics, but it is not reducible to them, among other things because it is deeply meshed into ongoing interactions with the physical, ecological, social, and intellectual environment.”

The above selected quotes are just a small portion of the many that are worth reading and pondering. Ellis emphatically demonstrates the many ways in which top-down causation works in concert with bottom-up causation to create the mind. This is how physics underlies the mind. It is the bottom level that causes the higher levels to exist and to function. But that physics is constrained and guided by the top-down causation of the higher levels. He shows how the highest levels involve large-scale interaction with our environment—our peers, our culture, and even Platonic entities. In this way, the mind emerges from the brain, an awesome interaction both vertically and horizontally.

Tags:  Ellis  Emergence  Mind 

Share |
PermalinkComments (0)
 

Ellis--Chapter Six: The Foundations: Physics and Top-Down Causation

Posted By Randall D. Isaac, Tuesday, October 4, 2016

This was another very enjoyable chapter for me and would be for any condensed matter physicist. Here Ellis digs down deep into the lower levels where physics dominates. Reductionists see everything being driven by physics at these levels. “At the bottom level, what happens is based on physics: it enables the emergence of higher level entities, which then in turn act down on the lower level components. Hence top-down causation takes place also in the context of physics.”

At the bottom level we find quantum dynamics. In sharp contrast to classical dynamics, we find inherent unpredictability. The state of a system evolves dynamically and collapses into an eigenstate only when a measurement is made or there is an interaction with another physical entity.

“Because the electronic band structures and the resultant lower level entities such as phonons are based on the higher level crystal structure rather than simply being based solely on properties of the lower level constituent, they are both emergent phenomena. They simply would not exist if the macro-structure did not exist.” Ellis goes on to use my favorite examples of emergence from my own fields of expertise, superconductors and semiconductors. Both materials exhibit unique particles such as Cooper pairs and holes and excitons that could exist only through the structural nature of a large ensemble of lower level particles, namely the ions and electrons that comprise the material. The top-down causation is the structural crystal lattice and the way in which the ions vibrate and respond to the electron cloud. None of these effects could be predicted on the basis of the independent particles alone. It is their interaction that enables the new particles and new behavior.

“…the higher levels of the hierarchy of complexity and causation provide the context within which the lower level actions take place. By setting the context in terms of initial conditions, boundary conditions, and structural relations, the higher levels determine the way the lower level actions occur.”

“The lower levels do the work, but the higher levels decide what is to be done.”

Ellis includes an interesting discussion of Olber’s Paradox which ponders why the night sky is dark. Integrating over an infinite universe would imply that the night sky should be dark. The fundamental reason for a dark night sky is that the universe is not infinite and the visual horizon is such that it is dominated by the cosmic background radiation. In other words, our universe is essentially a thermal bath at a temperature of 2.73K. The thermal gradient from the sun’s radiation to this bath temperature enables the energy driving force for evolution on the earth. Hence, he says “…the reason we observe the night sky to be dark is that if that were not true, we would not be here to see it.”

He also addresses the fascinating question of the arrow of time. Since all of the basic equations of physics are time invariant, being the same forward in time as backward, why should there be an arrow of time? Ellis says “The direction of time must be derived by a top-down process from cosmological to local scales.” In other words, the initial conditions and special boundary conditions at the big bang set up the entropy of the universe to be very small initially so that entropy always increases as the universe evolves.

Tags:  Ellis  Emergence  Mind 

Share |
PermalinkComments (0)
 

Ellis--Chapter Five: Room at the Bottom?

Posted By Randall D. Isaac, Friday, September 30, 2016

In this chapter, Ellis addresses whether top-down causation overdetermines a system. He asks “How can top-down causation be possible in the case of the implementation hierarchy, if the physics at the bottom is a causally closed system, determining all that happens through interactions of particles and fields mediated by forces and potentials? Isn’t the system already fully determined so there is no room for any kind of top-down causation?” In other words, this book is all about responding to reductionism.

This issue specifically arises when discussing the mind. “The claim can be made that physics does not just constrain what happens, it uniquely determines what happens in the brain. If basic physics determines all, the situation is causally closed and there is no room for higher level influences.” Ellis responds to this concern in this chapter, arguing that “…the underlying physics establishes the set of possibilities that can happen, but not the specific events that actually happen.”

Ellis offers five ways, which are not mutually exclusive, in which top-down effects can work:

1.       Contextual constraints

2.       Constraining structures

3.       Changing the nature of lower level elements

4.       Existence of lower level elements

5.       Deleting lower level elements

This was a delightful chapter to read, both for being shorter and also for having more interesting examples. In essence, Ellis cites numerous examples in which high-level entities set a context in which the lower-level entities interact. In this way, the causality from above influences the outcomes of the lower-level causal forces. Reductionism cannot explain the high-level constraints. The simultaneous bottom-up and top-down causality is truly a beautiful interplay between the many different levels of existence.

Tags:  Ellis  Emergence  Mind 

Share |
PermalinkComments (0)
 

Ellis--Chapter Four: Types of Top-Down Causality

Posted By Randall D. Isaac, Monday, September 26, 2016

 

In this chapter, Ellis works through seven different types of top-down causation:

1.       Deterministic top-down causation

2.       Non-adaptive feedback control

3.       Adaptive selection of outcomes

4.       Adaptive selection of goals

5.       Adaptive selection of selection criteria

6.       Complex adaptive systems

7.       Intelligent top-down causation

These seven types show a progression of very simple deterministic control to a far more dynamic and interactive type.

·       The deterministic type is the easiest to understand and sets the example. He discusses machines, physical systems, living systems, logical systems, mathematical models and randomness and noise. Machines are the archetypal examples of deterministic causation. Even for living systems, there is a basic deterministic level. Ellis describes it this way “…biology is based on molecular machines at the lower level, which behave in a deterministic way and affect higher levels in a bottom-up manner. This happens through physics processes at the lower levels in the context of systems structured so as to have specific functions. The outcomes depend crucially on context. Again it happens by:

o   Setting boundary conditions for differential equations.

o   Setting values for contextual variables.

o   Passing signals via messenger molecules.

o   Constraining lower level causation through structural conditions.”

·       Feedback control systems are familiar to all of us. The simplest is the thermostat which we use frequently. Our world is filled with control systems from the simple thermostat to complex engineering control systems to biological systems where there are many homeostatic systems. “Feedback control systems depend essentially on information flows from system sensors to the controller.” Feedback control, Ellis says, is top-down causation because of two factors:

o   Effectiveness of goals which are at a higher level than the controlled system

o   The system acts as a whole.

·       Adaptive systems. Ellis discusses four different types of adaptive selection processes:

o   Adaptive selection of outcomes

o   Adaptive selection of goals

o   Adaptive selection of selection criteria

o   Complex adaptive systems

In many ways, this is the heart of the book. Essentially adaptation is a feedback control system in which the feedback system changes or adapts by changing outcomes, goals, criteria or a combination of them. He notes that “adaptive processes…take place when there is

 

·       Variation of Interacting Entities

·       Selection of Preferred Entities”

At lower levels of the hierarchy, entities such as protons and neutrons have virtually no variation. They are each the interactions of three component quarks but there is no variation. Atoms in molecules have very limited quantized variations possible but no significant variation. More complex entities, like snowflakes, come in a large variety of shapes but they do not change and their differences in configuration have little impact on their properties. But at higher levels of complexity, entities can differ from each other and can change in response to external stimuli.

Ellis eloquently charts the set of adaptive processes and shows its power, for example, in generating new information. “The key process is deletion of what is not wanted, leaving what is meaningful. It is also for this reason that it can innovate. The process generates new information that was not there before, or rather, finds information that was hidden in noise.”

In the section on adaptive selection of selection criteria, Ellis delves deeper into learning theory and into the mind itself.

“Between them, ethics, aesthetics, and meaning form the topmost level of the hierarchy of adaptive selection criteria…They are the highest level abstract principles that are causally effective in the real physical world, crucially guiding what happens in choosing goals at all levels.”

Ellis collects all these different levels of selection into the category of “Complex Adaptive Processes”. He explains that “Adaptive processes take place when many entities interact, for example, the cells in a body or the individuals in a population, and variation takes place in the properties of these entities, followed by selection of preferred entities that are better suited to their environment or context.”

Finally, Ellis comes to intelligent top-down causation. This occurs when symbolic representation guides what happens. “A symbolic system is a set of structured patterns, realized in time or space, that is arbitrarily chosen by an individual or group to represent objects, states, and relationships.”

This chapter is one of the longest and difficult to read. It is really the heart of the book whose purpose is to show that top-down causality exists and is ubiquitous. Part of it is catalog style which makes for choppy reading but it does demonstrate the incredible range of top-down causal processes. In this chapter, and so far in this book, Ellis hasn’t attempted to show how these systems came into being. Rather he is describing what systems are like and showing that these causal factors play a key role in virtually all the systems we build and observe.

Tags:  Ellis  Emergence  Mind 

Share |
PermalinkComments (0)
 

Ellis--Chapter Three: The Basis of Complexity

Posted By Randall D. Isaac, Tuesday, August 2, 2016

This chapter delves more specifically into the essence of emergence. Ellis points out that emergence requires three aspects: modular, hierarchical, and structure. He explains that “hierarchical structures have different kinds of order, phenomenological behavior, and descriptive languages that characterize each level of the hierarchy.” As a simple example, consider the hierarchy of elementary physics, nuclear physics, atomic physics, and chemistry. Each layer of the hierarchy has a different kind of order and behavior. Elementary physics combines quarks into protons, neutrons, etc. Nuclear physics combines protons and neutrons into nuclei while atomic physics looks at nuclei coupled with electrons. Chemistry emphasizes the combination of atoms into molecule structures. And so on. A different descriptive language is required at each level. The concepts at one level would not be appropriate for a different level. Describing water molecules in terms of quarks would be useless.

Ellis provides a diagram of how one might describe the hierarchical levels in both inanimate and biological entities:


Ellis notes that it is unclear what the topmost and bottommost levels of the hierarchy are.  To find bottom, one might need to go to quantum gravity or something and that may not be the lowest either. The top appears to be a metaphysical level and who knows if there is more to the story. But the concepts are nevertheless effective without knowing the limits of the levels.

At each level, the dominant entities form modular structures that comprise the entities of the next higher level in the hierarchy. The elementary physics level is comprised of quarks that combine into a modular form of protons and neutrons which comprise the entities of the nuclear physics level, etc. Working at the nuclear physics level, one can ignore the structure of quarks and study the nucleons as a module. Ellis describes this as “information-hiding” in the sense that a higher level can hide the detailed information in the next lower level. The high levels of macroscopic materials need little or no specific information of the individual atoms and molecules. That information is conveniently hidden.

Abstraction occurs whenever a module can be treated as a single unit and referred to by some appropriate label. In the simplest case above, the label “proton” refers to the module of three specific quarks. Encapsulation is whenever the internal workings of an abstract module are completely hidden. No characteristic of the module depends on the details of the components.

Bottom-up causation is well-known and is generally considered unique and sufficient in a reductionist perspective. The atoms and molecules behave according to well-known laws of nature and that action comprises the characteristic of the cell and so on up the hierarchy. Strong reductionism would claim that all behavior could be explained by such bottom-up causation. Such explanations are limited only by the complexity of expressing the equations.

Ellis claims “the phenomenon of emergent order is when higher levels display new properties not evident at the lower levels…higher level structures are created out of lower level entities and then exist as entities in their own right. They are described by suitable higher level variables.”

Variables that describe traits are “structural if they are basically of a static nature—they give the higher level its identity; and they are dynamic if they are essential to its behavior—they are time dependent in crucial ways.

Definitions:

Bottom-up causation “is the ability of lower levels of reality to have a causal effect on the higher levels which emerge from them, sometimes uniquely determining what happens at the higher levels.

Top-down causation “is the ability of higher levels of reality to have a causal power over lower levels.

“Emergence of complexity takes place where quite different laws of behavior hold at the higher levels than at the lower levels.” In my field of condensed matter physics, I understand this as phenomena like semiconductivity or superconductivity of macroscopic solids represent fundamentally different laws of behavior than those at the level of individual atoms. Yet the higher level is entirely determined by the behavior of the lower level. The key is that there is also top-down causation in the sense that that higher level behavior is context-dependent. External constraints limit the action of the elements of the lower level.

Multiple representation occurs when many different microstates of one level all correspond to the same higher level state. For example, many different combinations of individual molecular positions and velocities correspond to the same volume and pressure of a gas. The number of different lower level representations determines the entropy of that state.

“…emergence is when phenomena arise from and depends on more basic phenomena yet are simultaneously autonomous from that base…A phenomenon is emergent if it cannot be reduced to, explained, or predicted from its constituent parts.”

Ellis argues that top-down causation can occur if and only if there are equivalence classes of lower-level states. Consider a state in some level that can result from many different lower-level states, as in the case of multiple representation. This state “must lead to the same top level outcome, independent of which lower level states instantiates the high level state.” He calls this the Principle of Equivalence Classes. In other words, changing a high level variable will lead to a change in the lower-level equivalence class for that variable but this change cannot depend on which member of the equivalence class exists at the time of the change. Only in this way can there be consistency and reproducibility of the effect of changing a high level variable. Only then can top-down causation work and in that case, top-down causation does happen.

Ellis discusses four ways in which top-down causation can be demonstrated.

1.       Altering context. Changing a high-level variable reliably induces change in the system.

2.       Identifying equivalence classes. One can show directly that equivalence classes exist.

3.       Identifying dynamics. One can show specific mechanisms that effect top-down control or specific feedback control systems.

4.       Computer Modelling. One can model hierarchies and demonstrate the top-down causation.

Finally, he points out that the lower levels set constraints on the properties that higher levels can realize. For example, matter and energy conservation laws at the low levels put limits on the higher level possibilities.

This chapter is more theoretical than chapter two. He introduces and defines many core concepts of emergence. There seems to be a lot of overlap with chapter one, largely due to the independence of each chapter. Here he expands in detail the concepts of emergence and complexity mentioned in chapter one. It’s not easy reading but I’ve almost deluded myself into thinking that I might actually be starting to understand it.

Tags:  Ellis  Emergence 

Share |
PermalinkComments (2)
 

Ellis--Chapter Two: Digital Computer Systems

Posted By Randall D. Isaac, Tuesday, July 12, 2016

This is the chapter I would have loved to have been able to write. My career was in digital computer design and fabrication and I am very interested in emergence so a chapter on computers as examples of emergence is right down my alley. Of course, Ellis does a far better job than I ever could.

Anyone who has written software programs or done circuit design for chips or any microprocessor architecture work will find this chapter easy to understand. Anyone who hasn’t done anything in this field is well advised to simply skip it. Ellis shows how a digital computer system exhibits top-down causation by emergent entities. With well-known concepts, he clarifies the concepts of emergence.

He describes computer systems as having two primary hierarchies. One is an implementational (vertical) hierarchy and the other is a logical (horizontal) hierarchy. Each hierarchy involves many levels of modular structures. For example, in the implementational hierarchy, one of the lowest levels is the atoms and molecules level. A higher level is the transistor and wiring level that form the physical layout. Above that, the transistors are combined into logic and memory circuits while above that, the circuits are combined into modules such as the arithmetic control unit, the central processing unit, etc. The highest level is the physical interface with humans. On the software side, the lowest level is the binary code that runs on the hardware. Next is assembly language and sequentially higher-order compilers and sophisticated programming languages. Modular units like subroutines are closed entities comprised of lower level commands.

Ellis explains “Each higher level behavior emerges from the lower level ones. But what ultimately determines what happens? The higher levels drive the lower levels.” This, he claims, is the essence of top-down causation. It is intrinsically coupled with bottom-up causation since the behavior of the lower levels causes the desired action at the higher levels. The higher levels are characterized by what can be considered abstract entities that interact and cause the appropriate desired action at the lower levels.

Then Ellis uses a term which I believe is potentially confusing and needs some discussion. He emphasizes that the entities in the higher level logical hierarchy are non-physical. He states that “Software is not a physical thing, neither is data. They are realized, or instantiated, as energetic states in computer memory. The essence of software does not reside in their physical nature: it is the patterns of states, instantiated by electrons being in particular places at a particular time, that matters.” What does it mean to be “non-physical?” As Christians we are very comfortable with non-physical beings and we quickly associate non-physical entities with spiritual ones. But I do not believe Ellis is using the term this way. By non-physical, I believe he means an entity that is not uniquely associated with a physical state. It may be the result of any number of physical states but its existence does not depend on any specific one.

While Rolf Landauer reported to me at IBM Research in the late 90’s, he told me in our personal discussions that “Information is physical, but independent of its embodiment.” I’m still struggling to understand this more fully. Information can be transferred from one physical embodiment to another without any necessary energy dissipation but deleting one bit of information necessarily dissipates kt ln 2 of energy. I’m also trying to figure out whether Landauer would agree with Ellis about software being non-physical because it is independent of its physical embodiment. I suppose being independent of physical embodiment may not be sufficient to warrant the term “non-physical.” In any case, we cannot assume that either Landauer or Ellis are thinking of spiritual-like entities when they talk about “non-physical” entities.

Finally, Ellis closes this chapter with this gem: “At a higher level, the existence of computers is an outcome of the human drive for meaning and purpose: it is an expression of the possibility space of meanings, the higher levels whereby we guide what actions take place.” As is true of so many sentences in this book, I have to read it many times to think it through. And maybe it wouldn’t make sense without reading the whole chapter. But I was in the business of designing and building computers all my career and never thought of it this way.

What he seems to be saying is that as we go up the physical and logical hierarchies, entities emerge from the lower levels with increasing abstraction. Finally, we get to the top levels where meaning and purpose reside. The closely linked relationships of bottom-up and top-down causation lead to the possibility of meaning and purpose, aspects that do not exist at the lower levels. We often say that science cannot address meaning and purpose but in Ellis’ view, emergence allows us to recognize meaning and purpose at the top levels even though it is absent at the lower levels. This I must contemplate for a while.

Tags:  computers  Ellis  Emergence 

Share |
PermalinkComments (1)
 

Comments on "How Can Physics Underlie the Mind?"

Posted By Randall D. Isaac, Monday, July 4, 2016

When I learned that George Ellis had just published a major work, I jumped at the chance to write a book review for PSCF. Springer publishing company only provides an online reader version for reviewers, with a free book after the review is published. But I’ve finally figured out the technical aspects of their reader and I’ve begun to read “How Can Physics Underlie the Mind: Top-Down Causation in the Human Context.” I would like to use this blog as a mean of writing notes to myself as I go through the back and hopefully that will help me write the review. Your comments and questions would be of great help if you are interested in the topic in any way. If not, simply ignore this post and its comments.

Ellis is in the Department of Mathematics and Applied Mathematics at the University of Cape Town, South Africa. He co-authored The Large Scale Structure of Space-Time with Cambridge physicist Stephen Hawking. He has long interacted with scholars such as ASA Fellow Robert Russell, Nancey Murphy, Tim O’Connor as well as Phil Clayton and other advocates of emergence. I have been interested in and persuaded by the ideas of emergence for many years and am eager to learn about some of the more detailed issues connected with it.

He writes that his aim in the book is to “…support the view that, even though physical laws underlie all material entities, there exist higher level causal relations that allow the brain to act as a means of creating theories, searching for meaning, expressing tenderness, and doing all the other myriad things that make us human, without contradicting or overwriting those lower level physical laws. Consequently, physics does not control the mind, it enables the mind. The same is true for genetics and neurobiology: they both to some degree shape what the mind does, but neither by itself determines the outcome, because the mind has a logic of its own…We are genuinely fully human, even though we emerge through the interactions of fundamental particles.”

The book has eight chapters:

1.       Complexity and Emergence

2.       Digital Computer Systems

3.       The Basis of Complexity

4.       Kinds of Top-Down Causation

5.       Room at the Bottom?

6.       The Foundation: Physics and Top-Down Causation

7.       The Mind and the Brain

8.       The Broader View

Springer asked Ellis to write the book in such a way that each chapter could stand alone and be sold separately as well as a complete book. This results in a significant amount of repetition, especially of references, but that repetition is very helpful in gaining familiarity with complex ideas.

So with that as a background, I’ll start to dig in and occasionally share with you his ideas.

Tags:  Ellis  Emergence  Mind  Physics 

Share |
PermalinkComments (4)