Anti-Reductionist Philosophy of Science Against Mechanism, #2.

(Murray, 2024)

TABLE OF CONTENTS

2. Cronin-Walker Assembly Theory and the Anti-Reductionist Turn

3. Physics is Not Causally Closed: Nicolas Gisin’s Anti-Mechanism

4. Barbara Drossel’s Anti-Reductionism

5. Donald Hoffman’s Case Against Reality: There are No Brains

6. Colin McGinn’s Basic Structures of Reality: A Philosophical Analysis of Physics-Based Metaphysics and Structural Realism

7. Thomas Nagel’s Mind and Cosmos: A Defense of Teleological Naturalism and a Critique of Materialist Reductionism

8. Kevin Mitchell’s Free Agents: A Biological Case Against Mechanistic Determinism

9. Conclusion

The essay below will be published in six installments; this, the second, contains section 3.

But you can also download and read or share a .pdf of the complete text of the essay, including the REFERENCES, by scrolling down to the bottom of this post and clicking on the Download tab.

3. Physics is Not Causally Closed: Nicolas Gisin’s Anti-Mechanism

In this section, we examine the arguments presented by physicist Nicolas Gisin about the causal non-closure of physics and the implications of thse arguments for free will and anti-mechanistic views of nature. Gisin, drawing on insights from quantum mechanics, nonlinear dynamics, and mathematical logic, argues that the physical world is not causally closed, that is, not all physical events are fully determined by prior physical causes (Gisin, 2009, 2014, 2016, 2021; Gisin and Percival, 1991) This position challenges mechanistic determinism while also providing conceptual space for genuine agency and free will. We analyze Gisin’s mathematical arguments about real numbers, indeterminacy in classical mechanics, quantum non-locality, and time’s fundamental asymmetry, examining how these converge to support an anti-mechanistic worldview that rejects the mechanistic world view at the fundamental level of basic physics.

The question of whether physics describes a causally closed system has profound implications for our understanding of human agency, consciousness, and free will. Traditional mechanistic views, dating from Laplace’s demon through contemporary physicalism and mechanism, assume that all physical events are fully determined by prior physical causes operating according to deterministic laws. This causal closure thesis appears to leave no room for genuine agency or libertarian free will.

Gisin, a distinguished physicist at the University of Geneva known for his work in quantum information and foundations of quantum mechanics, has developed a sophisticated argument against the causal closure of physics. His position is not based on supernatural intervention or dualistic assumptions, but emerges from careful analysis of fundamental features of physical theory itself. Gisin argues that indeterminacy, genuine randomness, and temporal asymmetry are irreducible features of physical reality that prevent the closure of causal chains.

Causal closure in physics refers to the thesis that every physical event has a sufficient physical cause. Therefore, the physical world is causally closed and complete. This principle, also known as the causal closure of the physical, implies that if we knew all physical facts at any given time and understood all physical laws, we could in principle predict all future physical states.

The causal closure thesis has been central to mechanistic worldviews since the Scientific Revolution. It underlies not only classical determinism but also contemporary physicalist and mechanistic approaches to the mind-body problem. If physics is causally closed, then mental causation appears impossible: how can mental states cause physical events if all physical events already have sufficient physical causes?

Pierre-Simon Laplace famously articulated the mechanistic vision in terms of a hypothetical intelligence (aka, “Laplace’s demon”) that could know the position and momentum of every particle in the universe. Such an intelligence could, according to Laplace, predict the entire future and map the entire past with perfect accuracy.

Gisin argues that this Laplacian vision, while historically important, rests on mathematical and physical assumptions that are untenable. The vision requires not only deterministic laws, but also the assumption that physical systems can be described with arbitrary precision using real numbers and that these descriptions correspond to genuine physical properties.

Contemporary debates about mental causation often center on the exclusion problem: if every physical event has sufficient physical causes, then mental causes appear to be either epiphenomenal or reducible to physical causes. This creates fundamental difficulties for understanding agency, responsibility, and the causal efficacy of reasons and intentions.

Gisin’s arguments provide a novel approach to these problems by challenging the underlying assumption of causal closure rather than attempting to reconcile agency with closed causal chains. If physics is not causally closed, then there may be genuine causal gaps where agency can operate without violating physical laws.

One of Gisin’s most important arguments concerns the role of real numbers in physical theory. Standard formulations of both classical and quantum mechanics employ real numbers to describe physical quantities like position, momentum, and energy. However, Gisin argues that this mathematical formalism creates problems for both computational and conceptual understanding of physical systems.

Real numbers contain infinite amounts of information. Hence to specify a real number exactly requires infinite precision, which cannot represent physical reality. This creates what Gisin calls the “information problem”: if physical properties correspond to real numbers, then finite physical systems would contain infinite amounts of information, which seems problematic both computationally and physically.

Moreover, most real numbers are non-computable, that is, they cannot be calculated by any algorithm, even with unlimited time and resources. If physical properties correspond to arbitrary real numbers, then the physical world would contain non-computable information, creating fundamental barriers to prediction and understanding.

Gisin suggests that physical measurements and computational processes actually operate with finite precision, corresponding to rational rather than real numbers. Rational numbers, being computable and finite in their information content, provide a more realistic foundation for physical description.

This shift from reals to rationals has profound implications for determinism and predictability. While differential equations with real-valued initial conditions might have unique solutions, the same equations with rational-valued initial conditions may exhibit fundamentally different behavior, including genuine indeterminacy.

The finite precision argument suggests that even apparently deterministic classical systems may exhibit unpredictable behavior not due to practical limitations—i.e., sensitive dependence on initial conditions—but instead due to fundamental indeterminacy in the rational approximations to real-valued quantities.

Building on work by Stephen Wolfram and others, Gisin argues that many physical processes are computationally irreducible, in the sense that no shortcut description can outpace the process itself, so prediction is inherently limited. This computational irreducibility creates fundamental barriers to prediction that go beyond practical limitations.

If many physical processes are computationally irreducible, then perfect prediction becomes impossible even in principle, not just in practice. This algorithmic limitation suggests that the physical world contains irreducible novelty and creativity that cannot be captured by mechanistic description.

The combination of finite precision and computational irreducibility means that physical systems may exhibit genuine indeterminacy that cannot be eliminated by better measurement or computation. This indeterminacy provides conceptual space for agency and free will.

Gisin’s expertise in quantum mechanics provides another line of argument against causal closure. Standard quantum mechanics contains irreducible probabilistic elements that appear to represent genuine randomness rather than mere epistemic uncertainty about underlying deterministic processes.

Bell’s theorem, which Gisin has contributed to developing and testing experimentally, demonstrates that local realistic theories cannot reproduce all quantum mechanical predictions. This result suggests that either locality or realism (or both) must be abandoned, creating problems for mechanistic pictures of nature.

Gisin argues that Bell’s theorem supports a non-mechanistic interpretation of quantum mechanics where measurement outcomes are not determined by prior physical states but involve genuine causal gaps. These gaps represent points where the causal chain is broken and new information enters the physical world.

Quantum entanglement and non-locality present further challenges to mechanistic causation. Entangled systems exhibit correlations that cannot be explained by local causal connections, suggesting forms of holistic causation that transcend the mechanistic picture of local interactions between discrete parts.

Gisin’s work on quantum teleportation and quantum communication demonstrates that quantum systems can exhibit causal relationships that are fundamentally different from classical mechanical interactions. These quantum causal relationships suggest that nature may operate according to non-mechanistic principles at fundamental levels.

The holistic character of quantum causation provides a model for understanding how mental causation might operate without violating physical laws. Just as quantum systems can exhibit non-local correlations, mental systems might exhibit non-mechanistic causal relationships with physical systems.

The quantum measurement problem, the question of how definite outcomes emerge from quantum superpositions, represents another challenge to causal closure. If measurement outcomes are not fully determined by prior physical states, then the measurement process introduces genuine novelty into the physical world.

Gisin argues that consciousness may play a fundamental role in quantum measurement, not through supernatural intervention, but through the natural capacity of conscious systems to actualize potentialities. This suggests a form of mental causation that operates within, rather than against, the natural order.

The quantum measurement problem indicates that the physical world may be fundamentally incomplete without conscious observers who can actualize quantum potentialities. This incompleteness represents a form of causal non-closure where mental processes play constitutive rather than merely epiphenomenal roles.

Even within classical mechanics, chaotic systems exhibit sensitive dependence on initial conditions that makes long-term prediction practically impossible. Small uncertainties in initial conditions grow exponentially, leading to rapid loss of predictive power.

While chaos theory is often interpreted as showing that deterministic systems can appear random, Gisin argues for a stronger conclusion: that chaotic systems may exhibit genuine indeterminacy rather than merely apparent randomness. This reinterpretation depends on the finite precision arguments discussed earlier.

If initial conditions can only be specified with finite precision (corresponding to rational rather than real numbers), then chaotic systems may have multiple possible evolutionary pathways that are genuinely undetermined by prior states. This represents a form of causal non-closure within classical mechanics itself.

Gisin points out that chaotic systems often exhibit structural instability, small changes in parameters can lead to qualitatively different behavior. This structural instability suggests that the mathematical models used to describe physical systems might be fundamentally inadequate for perfect prediction.

The presence of structural instability means that physical systems might be poised at critical points where small influences can have large effects. These critical points represent potential sites for agency to operate without violating conservation laws or other physical constraints.

Structural instability also indicates that physical systems can exhibit emergent properties that cannot be predicted from knowledge of their components and initial conditions. This emergence represents a form of genuine novelty that challenges reductionist explanations.

The mathematical theory of dynamical systems reveals complex topological structures in phase space that can lead to unpredictable behavior even in low-dimensional deterministic systems. These structures include strange attractors, homoclinic tangles, and fractal boundaries between basins of attraction.

Gisin argues that these complex phase space structures represent irreducible features of physical systems that cannot be eliminated through better approximation or computational methods. The topological complexity of phase space means that prediction requires more than just knowing initial conditions and evolution equations.

The presence of complex attractors and fractal structures strongly suggests that physical systems can exhibit forms of self-organization and spontaneous order that transcend mechanistic explanation. These phenomena provide natural analogies for understanding how conscious agency might emerge from and operate within physical systems.

Standard physics equations are time-reversible, yet we experience a clear direction of time with causes preceding effects. This temporal asymmetry represents a fundamental puzzle for mechanistic worldviews that treat time as merely another dimension analogous to space.

Gisin argues that the arrow of time is not merely emergent from statistical mechanics or boundary conditions but represents a fundamental feature of physical reality. This temporal asymmetry breaks the symmetry assumptions underlying mechanistic determinism.

The irreversible flow of time suggests that the future is fundamentally different from the past, that the future represents genuine possibilities rather than predetermined outcomes. This temporal asymmetry provides conceptual space for agency to operate in determining which possibilities become actualized.

The Second Law of thermodynamics describes irreversible increases in entropy, representing a clear temporal asymmetry in physical processes. Gisin argues that this thermodynamic irreversibility reflects deeper features of time and causation that cannot be reduced to mechanical interactions.

Thermodynamic processes involve information growth, the creation of new degrees of freedom and correlations that were not present in initial conditions. This information growth suggests that physical processes are genuinely creative rather than merely rearranging pre-existing elements.

The irreversible character of information growth means that the future cannot be fully predicted from the past because genuinely new information is created through physical processes. This creativity provides a natural context for understanding agency and free will.

Gisin holds that time in general relativity and cosmology has a global structure that differs fundamentally from the local time of special relativity or classical mechanics. The expanding universe provides a cosmic temporal framework that distinguishes past from future at fundamental levels.

The cosmological arrow of time suggests that temporal asymmetry is built into the fabric of spacetime rather than emerging from local physical processes. This global temporal structure provides a framework within which agency and creativity can operate.

The expansion of the universe also creates new space and possibilities over time, suggesting that the future literally contains more possibilities than the past. This expanding possibility space provides room for genuine choice and agency.

Gisin’s arguments provide support for libertarian incompatibilist rather than compatibilist approaches to free will. Compatibilists attempt to reconcile free will with determinism by redefining freedom in terms of acting according to one’s desires without external coercion. Libertarian incompatibilists insist that genuine freedom requires genuine alternatives and the ability to influence the future in ways not fully determined by the past.

The causal non-closure of physics provides conceptual space for libertarian free will by creating genuine gaps in causal chains where agency can operate. These gaps are not violations of physical laws but natural features of a fundamentally nondeterministic universe.

Gisin’s approach avoids both supernatural dualism and reductive materialism by locating agency within the natural causal gaps that exist due to quantum indeterminacy, chaotic dynamics, and temporal asymmetry. Agency operates through rather than against natural processes.

The non-closure of physics allows for forms of agent causation whereby rational human animals can influence physical events without violating conservation laws or other physical constraints. Agent causation operates through the natural quantum indeterminacies present in physical systems.

Mental states and processes can influence physical events by biasing probabilities or selecting among available possibilities rather than creating energy or momentum ex nihilo. This form of mental causation respects physical constraints while allowing for genuine efficacy.

Agent causation may operate through quantum mechanical measurement processes, chaotic amplification of small influences, or other natural mechanisms that allow mental processes to influence physical events. The key insight is that these influences work with, rather than against, natural processes.

Gisin claims that consciousness may play a fundamental role in quantum measurement by actualizing quantum potentialities. This does not require consciousness to have non-physical properties, but instead says that conscious processes have natural capacities to resolve quantum indeterminacies.

The relationship between consciousness and quantum measurement provides a model for understanding how mental processes can influence physical events without supernatural intervention. Conscious observation naturally selects among available quantum possibilities.

This quantum-mechanical account of mental causation avoids the problems of dualistic interaction while preserving the causal efficacy of consciousness. Mental processes operate through natural quantum mechanical processes rather than transcending them.

Gisin’s arguments challenge reductionist explanations that attempt to understand complex systems entirely in terms of their simpler components. The non-closure of physics suggests that complex systems may exhibit irreducible properties that cannot be predicted from knowledge of their parts.

The presence of computational irreducibility, quantum holism, and temporal asymmetry means that higher-level properties may be genuinely emergent rather than merely apparent. This emergence is not mysterious but instead reflects the fundamental indeterminacy present in physical systems.

Anti-reductionist emergence provides conceptual space for understanding consciousness, agency, and other complex phenomena without requiring supernatural explanations. These phenomena emerge naturally from the non-mechanistic features of physical reality.

The non-closure of physics supports holistic and systems approaches that accept the irreducible properties of wholes. Quantum entanglement provides a paradigm case of a holistic phenomenon that cannot be understood solely in terms of independent parts.

Systems approaches that adopt circular causality, feedback, and self-organization align naturally with Gisin’s non-mechanistic vision. These approaches recognize that systems can exhibit properties that transcend the sum of their parts.

The holistic character of non-mechanistic systems provides natural contexts for understanding consciousness, life, and agency as emergent but irreducible features of complex physical systems.

Gisin’s position on temporal asymmetry and the flow of time aligns with process philosophy traditions that stress becoming over being. The non-closure of physics supports views that treat change and creativity as fundamental rather than derivative features of reality.

Process approaches that accept the primacy of events, relations, and temporal development, provide philosophical frameworks compatible with Gisin’s physics. These approaches treat substance and mechanism as abstractions from more fundamental processes.

The compatibility between non-closed physics and process philosophy suggests possibilities for developing naturalistic metaphysics that preserve agency and creativity while remaining consistent with scientific understanding.

Critics often argue that quantum randomness cannot ground free will because random events are not under the control of agents. If quantum indeterminacy is genuinely random, how can it provide the basis for responsible agency?

Gisin’s response is that genuine agency requires more than randomness, but also more than determinism. Agency operates through biasing probabilities and selecting among available possibilities rather than determining outcomes with certainty. This probabilistic control is sufficient for responsibility and meaningful choice.

The quantum measurement process provides a model for how conscious agents might influence probabilities without determining outcomes. Consciousness can bias quantum measurements toward preferred outcomes while respecting the irreducible probabilistic character of quantum mechanics.

Another objection argues that if physics is not causally closed, then successful prediction should be impossible. Yet physics has been remarkably successful at predicting natural phenomena, thereby indicating that causal closure must be approximately correct.

Gisin argues that predictive success in physics depends on studying systems in controlled laboratory conditions that minimize the influence of causal gaps. Many physical systems exhibit predictable behavior over limited time scales even if they are not perfectly deterministic.

Moreover, the success of statistical mechanics and thermodynamics shows that predictable macroscopic behavior can emerge from indeterministic microscopic processes. Causal non-closure is compatible with reliable statistical predictions.

Some critics worry that denying causal closure opens the door to supernatural explanations and undermines scientific naturalism. If physical events are not fully determined by physical causes, does this require non-physical influences?

Gisin’s approach remains fully naturalistic by locating causal gaps within physics itself rather than appealing to supernatural intervention. The indeterminacies that prevent causal closure are natural features of quantum mechanics, chaos theory, and thermodynamics.

Agency operates through natural processes rather than transcending them. Mental causation works by influencing probabilities and actualizing possibilities that are already present in physical systems. This preserves naturalism while allowing for genuine agency.

Gisin’s experimental work on Bell inequality violations provides empirical support for quantum non-locality and the breakdown of local realism. These experiments demonstrate that nature violates the assumptions underlying mechanistic causation.

The violation of Bell inequalities in carefully controlled experiments shows that quantum mechanical predictions are correct and that local realistic theories cannot account for all natural phenomena. This provides direct empirical evidence against the mechanistic worldview.

Ongoing experiments with quantum entanglement, quantum teleportation, and quantum communication continue to confirm the non-local and indeterministic character of quantum mechanics, thereby supporting Gisin’s anti-mechanistic conclusions.

Research on chaotic systems provides empirical evidence for the limits of predictability in classical mechanics. Studies of weather systems, population dynamics, and other chaotic phenomena demonstrate the rapid growth of uncertainties that make long-term prediction impossible.

The discovery of strange attractors, fractal structures, and other complex dynamical phenomena shows that even simple deterministic equations can produce unpredictable behavior. This supports Gisin’s arguments about the limits of mechanistic explanation.

Computer simulations of chaotic systems reveal the sensitivity to finite precision arithmetic and computational limitations, supporting Gisin’s arguments about the role of rational approximations in physical description.

Neuroscientific research on decision-making and voluntary action provides relevant empirical data for evaluating theories of free will. Studies of brain activity during decision-making reveal complex patterns that may be compatible with Gisin’s anti-mechanistic approach.

Research on quantum effects in biological systems, including possible quantum processes in neural microtubules and other cellular structures, suggests various processes by which quantum indeterminacy might influence brain function.

Studies of top-down causation in neural networks show that higher-level mental processes can influence lower-level neural activity, thus providing evidence for forms of mental causation compatible with Gisin’s framework.

Gisin’s arguments have implications for the philosophy of science, particularly regarding the relationship between mathematical models and physical reality. The problems with real numbers in physics suggest that mathematical formalism may not correspond directly to physical properties.

The focus on computational limitations and algorithmic irreducibility challenges the assumption that better mathematical models necessarily lead to better understanding. Some aspects of physical reality may be irreducibly complex.

The non-closure of physics supports pluralistic approaches to scientific explanation that recognize multiple levels of description and forms of causation. Reductionist unity of science programs need to be reconsidered.

The causal gaps provided by non-closed physics offer new approaches to the mind-body problem that avoid both dualistic interaction and reductive materialism. Mental causation can operate through natural physical processes without being reducible to them.

The concern with temporal asymmetry and the flow of time provides resources for understanding consciousness and subjective experience. The subjective flow of time may reflect objective features of temporal structure.

Non-mechanistic approaches to mind-body interaction support views of consciousness as an irreducible but natural feature of complex physical systems. Consciousness emerges from, but is not reducible to, neural activity.

The defense of libertarian incompatibilist free will has implications for understanding moral responsibility and ethical agency. If agents can genuinely influence the future through free choices, then responsibility attributions are meaningful rather than merely pragmatic.

The probabilistic character of agency suggested by Gisin’s framework allows for degrees of freedom and responsibility that vary with circumstances and individual capacities. This provides resources for nuanced approaches to moral evaluation.

The natural character of agency means that moral responsibility is grounded in objective features of the world rather than merely subjective attitudes or social conventions. Ethics has genuine metaphysical foundations.

Gisin’s arguments for the causal non-closure of physics present a sophisticated framework for defending free will and challenging mechanistic worldviews. His multi-faceted approach draws on quantum mechanics, chaos theory, mathematical logic, and temporal asymmetry to argue that the physical world contains irreducible indeterminacies that prevent complete causal closure.

The strength of Gisin’s position lies in its grounding in established physics rather than speculative metaphysics. The quantum mechanical violation of Bell inequalities, the computational irreducibility of chaotic systems, the problems with real numbers in physical description, and the thermodynamic arrow of time all provide empirical and theoretical support for causal non-closure.

This non-closure creates conceptual space for libertarian free will without requiring supernatural intervention or violation of physical laws. Agency operates through natural indeterminacies by biasing probabilities and actualizing possibilities rather than determining outcomes with certainty. This probabilistic control is sufficient for moral responsibility and meaningful choice.

Gisin’s anti-mechanistic vision has broader implications for philosophy of science, philosophy of mind, and ethics. It entails that reductionist explanations are fundamentally inadequate for understanding complex phenomena like consciousness and agency. Instead, holistic and systems approaches that recognize irreducible emergence will be necessary.

The framework also provides resources for developing naturalistic but non-reductive approaches to consciousness and mental causation. Mental processes can influence physical events through natural mechanisms without being reducible to purely physical processes.

While Gisin’s arguments do face objections and require further development, nevertheless they represent a significant contribution to longstanding debates about determinism, agency, and the nature of physical reality. The combination of rigorous physics and careful philosophical analysis provides a model for addressing these fundamental questions.

The implications of causal non-closure extend beyond professional academic philosophy to practical questions about human agency, moral responsibility, and the nature of rational action. If the physical world is genuinely open to influence by conscious agents, this has profound consequences for how we understand ourselves and our place in nature.

Gisin’s work contributes to a growing body of research that challenges mechanistic reductionism while remaining committed to scientific naturalism. This research suggests possibilities for understanding agency and consciousness as natural but irreducible features of a fundamentally creative and nondeterministic universe.

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