May 29, 2013 | By George Gantz
Causation – another highly disputed concept in physics.
The common scientific explanation of causation follows the reductionist view that states that the interactions of the smallest structures cause the macro effects we actually see: Causation is a “bottom-up” process. But there are significant flaws in this model of causation that scientists (and theologians) have been struggling to address. A new model sees causation working top-down in multiple generative levels. This model may seem more complex, but it does a far better job at explaining the way the world works. And, however difficult it may seem, it is a model that is intuitively understood by children.
The scientific understanding of causation starts with what we see in the physical world. A white billiard ball strikes a red billiard ball “causing” it to move. But science also teaches us that this action-reaction event is caused by the physical properties of the billiard balls, properties that are in turn caused by the molecular components of the balls. These components and their behaviors, in turn, are caused by fundamental quantum particle/wave behaviors which physicists tell us are the very foundation of the universe. This line of causal reasoning follows the reductionist view that states that the interactions of the smallest structures cause the macro effects we actually see. These effects include all the features of the world as we know it: the stars and galaxies of the cosmos; all the chemical and physical phenomena including biology and life; the workings of computers; and the workings of the human mind. All of these things are “caused by” the minute quantum stuff of the universe. Causation is a “bottom-up” process.
This may seem to make sense, but there are significant flaws in this model of causation that scientists (and theologians) have been struggling to address. One broad criticism is that bottom-up causation leaves no place for free will, implying that our universe and our lives are stuck on a deterministic treadmill. From a theological perspective it also eliminates any continuing role for God – He may have started up the universe, but He is not needed to keep it running. In general terms, the reductionist model is inconsistent with any notion of “causal agency” – the idea that there are agents whose intentions can cause things to happen in the physical world. Yet, as we noted in our post on “Why Do Children Believe in God”, causal agency is something even young children observe and understand.
A more narrowly focused critique is that bottom-up causation cannot adequately explain how or why higher-level complexity (such as galaxies, life, consciousness) emerges from lower-level systems (e.g. physics). Theories of emergence and the implications for our notions of causality date back millennia but have received increasing attention in the past several decades. Interestingly, recent discussions in the scientific community appear to have led through several steps to conceptual formulations that may also open the door for free will, causal agency – and even God.
One of the early critiques of bottom-up-causation was by Nobel physicist Phillip W. Anderson, who noted in a paper in 1972, “The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. The constructionist hypothesis breaks down when confronted with the twin difficulties of scale and complexity. At each level of complexity entirely new properties appear.” According to Anderson, this hierarchical structure of increasing complexity arises as a function of “symmetry breaking” under which “the whole becomes not merely more, but very different from the sum of its parts.”
Symmetry breaking is a rigorous technical concept but the basic idea is that a new higher-level property can emerge when the system from which it emerges becomes less symmetrical. Imagine the primordial ooze, the stuff of life before life, squishing around in puddles. This is a relatively homogenous mass of stuff, which means it appears the same everywhere, i.e. it is symmetrical. At some point, some of the molecules begin to clump and the clumps begin to self-replicate – building larger clusters and exhibiting life-like characteristics. As this phenomenon takes hold, the ooze is no longer homogeneous – it has broken symmetry and is now showing a higher order of organization. Symmetry breaking is a key concept in physics and cosmology, and it provides a mechanism for increased levels of complexity to arise from simpler systems. However, the concept does not explain why symmetry breaks in the very specific ways that it does. Random or spontaneous symmetry breaking does not adequately explain emergence – in some cases there is something directing the symmetry breaking, i.e. some other “causative” factor.
In a paper published in 2012, George Ellis, noted cosmologist, states it this way: “The degree of complexity that can arise by bottom-up causation alone is strictly limited… spontaneously broken symmetry is powerful, but not as powerful as symmetry breaking that is guided top-down to create ordered structures (such as brains and computers). Some kind of coordination of effects is needed for such complexity to emerge.”
His theory, which he refers to as top-down causation, is that higher-level structure provides constraints (a kind of information) that guide the emergence of the higher order complexity. While the underlying systemic properties are the cause, the nature of the emergence is structured in specific ways from the top down. In his terms, there is a “reversal of information flow” from higher to lower order in the process of emergence from the lower to higher order. He enumerates several highly technical examples and postulates that bringing in the concept of top-down causation will significantly advance the sciences that are grappling with emergent phenomena. “… recognizing this feature will make it easier to comprehend the physical effects underlying emergence of genuine complexity, and may lead to useful new developments, particularly to do with the foundational nature of quantum theory.”
While this formulation seems to be making progress in allowing top-down influences on the emergence of higher order complexity, it equivocates on the nation of “cause” by relegating the higher order information to a secondary role in the process. Ellis also does not speak to the metaphysical implications and the question of why or how the information flow reverses to direct the emergence process. If the higher-order emergent property has not yet emerged, how can the end result generate an information flow? How does the emergent property bootstrap itself, so to speak?
One of the problems with these theories of causation seems to be that they view the stuff of the universe as things as they are in themselves – objects and their categorical properties (the properties which distinguish among them). These objects, or substances, interact and cause changes that are manifest as phenomena that we observe. But what if we were to add the concept of propensity or disposition to the objects of the universe – and then conceptualize the real substances of the universe (the things which really exist) as these dispositions and propensities. The result is known as dispositional essentialism – a fancy way of saying that the essence or substance of an object is the sum of all its dispositions and propensities – how it is disposed to behave in the various conditions to which it may be subjected. For example, one of the essential dispositions of glass is that it will shatter if struck – this fragility is part of the essence of the glass.
Brian Ellis and Caroline Lierse, in an article from March 1994, put it this way: “With few exceptions, the most fundamental properties that we know about are all dispositional. They are of the nature of powers, capacities and propensities…. The most fundamental kinds of things would appear to be distinguished from each other only by their causal powers, capacities and propensities.”
This provides a new basis for considering causation as the process by which the disposition of an object acts in the context of the object’s form and circumstances. Ian Thompson puts it this way: “Then, how these <objects and people> behave in the future is just a consequence of their particular kinds of propensities and desires, along with the forms and circumstances in which they find themselves.” p.76
Causation in this sense is similar to top-down causation, but puts the disposition (a higher level structure) as the primary cause and the circumstances and form of the underlying system as secondary. In the language of dispositional essentialism, there is a generative process of causation flowing from dispositions and a selective process resulting from the underlying circumstances of the object or system. In many cases, the result of the top-level disposition is to create or change dispositions at the next level, in a cascade of causation operating across multiple levels.
Thompson provides a series of examples of causation flowing though multiple generative levels in physics and psychology and reviews the work of a number of other experts in these fields. “Summarizing the quantum mechanical case, we see that here again, the principle causes act forwards down a set of multiple generative levels whose range of actions at any time is selected from all those presently possible, as constrained by past events.” P.67 When applied to psychology, the model places the role of intention (disposition) as central to the process of causation. Thompson also applies the model to the question of the highest generative level – the dispositions of God.
While this new model of causation working top-down in generative levels may seem more complex that the reductionist model we started with, it does a far better job at explaining the way the world works. It resolves all the criticisms of reductionism. And, however difficult it may seem, it is a model that is intuitively understood by children.
Anderson, P.W. (1972), “More is Different: Broken Symmetry and the Nature of the Hierarchical Structure of Science“, Science 177 (4047): 393–396
George F. R. Ellis, Recognising Top-Down Causation, FQXi Essay Contest – Spring 2012.
Brian Ellis and Caroline Lierse, Dispositional Essentialism, Australasian Journal of Philosophy, March 1994.
Dr. Ian Thompson, Starting Science From God: Rational Scientific Theories from Theism, (2011).
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