Quantum Mechanics and Inclusive Materialism

Abstract

Since its inception, the intricate mathematical formalism of quantum mechanics has empowered physicists to describe and predict specific physical events known as quantum processes. However, this success in probabilistic predictions has been accompanied by a profound challenge in the ontological interpretation of the theory. This interpretative complexity stems from two key aspects. Firstly, quantum mechanics is a fundamental theory that, so far, is not derivable from any more basic scientific theory. Secondly, it delves into a realm of invisible phenomena that often contradicts our intuitive and commonsensical notions of matter and causality. Despite its notorious difficulties of interpretation, the most widely accepted set of views of quantum phenomena has been known as the Copenhagen interpretation since the beginning of quantum mechanics. According to these views, the correct ontological interpretation of quantum mechanics is incompatible with ontological realism in general and with philosophical materialism in particular. Anti-realist and anti-materialist interpretations of quantum matter have survived until today. This paper discusses these perspectives, arguing that materialistic interpretations of quantum mechanics are compatible with its mathematical formalism, while anti-realist and anti-materialist views are based on wrong philosophical assumptions. However, although physicalism provides a better explanation for quantum phenomena than idealism, its downward reductionism prevents it from accounting for more complex forms of matter, such as biological or sociocultural systems. Thus, the paper argues that neither physicalism nor idealism can explain the universe. I propose then a non-reductionistic form of materialism called inclusive materialism. The conclusion is that the acknowledgment of the qualitative irreducibility of ontological emergent levels above the purely physical one does not deny philosophical materialism but enriches it.

1. Introduction

Since its inception, quantum mechanics has captured the imagination of philosophers, theologians, scientists, artists, and ordinary people. The common belief that the foundation of the universe, the deepest layer of reality, exhibits not just paradoxical but strange, almost magical features has led to fascinating scientific and philosophical theorizing. However, it has also resulted in the proliferation of pseudo-science, pseudo-philosophy, and pseudo-techniques (such as quantum shamans and quantum amulets!). Every year, the amount of pseudo-scientific and pseudo-philosophical literature that claims to be supported on quantum mechanics grows. It is difficult to find a metaphysical or even mythological assertion that has not attempted to be supported by quantum mechanics, from God, free will, and the multiverse to the existence of disembodied consciousness, the non-existence of independent reality, and even pure magic in the form of human entanglement and the like. The widespread acceptance of “quantum” nonsense has even permeated supposedly reputable academic journals, as demonstrated by the so-called Sokal hoax a few years ago [1].

In this paper, I will argue against these kinds of interpretations and defend the following points:

(1)

Every science, including quantum mechanics, is based on certain philosophical assumptions. Incorrect assumptions can lead scientific investigations to dead ends or incorrect interpretations.

(2)

A materialistic interpretation of quantum mechanics is far more coherent and compatible with the data and theory than idealistic, spiritualist, and theistic interpretations. According to anti-materialist interpretations, quantum phenomena:

(a)

Require consciousness to behave in specific ways.

(b)

Their stochastic nature demonstrates that ontological determinism does not apply at the quantum level.

(c)

Can exist in multiple states simultaneously, as shown by the wave–particle duality and superposition of states, which violates the principles of identity and contradiction.

(d)

Can interact with each other simultaneously regardless of the distance through quantum entanglement.

(e)

Only exist through fundamental physical constants such as the Planck constant (ℎ), which are fine-tuned for life. A slight change in these constants would make life impossible, which suggests the existence of a Great Designer behind the scenes of the material world.

I will critique each of these points in this paper.

(3)

Despite challenging idealistic and theistic interpretations of quantum mechanics, I also criticize reductionistic materialistic approaches for their inability to explain the emergent complexity and qualitative irreducibility of supra-quantum ontological levels in the universe. In other words, I defend not materialism in general but a very particular type of philosophical materialism that I will call inclusive materialism or non-flat materialism in the absence of a better name.

2. Quantum Mechanics and the Foundation of Reality

Quantum mechanics is the scientific study of the behavior of matter (and energy as a property of matter), mainly at the atomic and subatomic levels, but also for some macroscopic phenomena such as superconductivity and superfluidity. In this paper, I will refer to “quantum matter” as the physical systems and processes studied by quantum mechanics 1.

It is important to note that our understanding of quantum mechanics is limited. There are reasons to suppose that we cannot fully understand or explain quantum matter. Spacetime and quantum matter may be emergent realities that arise from more fundamental unknown entities [2,3,4,5,6,7]. Despite this uncertainty, quantum matter remains, along with spacetime, the most universal and general kind of matter we know so far. Another important consideration is that the name of quantum mechanics is misleading because quantum entities do not behave like punctate corpuscles with fixed positions and trajectories (except in idealized approximations). Therefore, quantum entities differ greatly from those studied in macrophysical mechanics [8,9,10,11].

While works of art, philosophical systems, religious beliefs, and social acts have unique characteristics that cannot be reduced to quantum matter, they are still dependent on it in complex ways. Sociocultural systems require humans or other similarly complex entities, which are themselves composed of biological systems made up of molecules, atoms, quarks, and leptons—all properties or perturbations of quantum fields. Therefore, while these entities are qualitatively different from quantum matter, they are still composed of it and cannot exist without it. In other words, quantum fields are the most fundamental feature of known reality.

The theory of quantum mechanics was developed by renowned scientists such as Max Planck, Albert Einstein, Louis de Broglie, and Niels Bohr. It reached its mature form in the 1920s and 1930s with the contributions of Werner Heisenberg, Max Born, Pascual Jordan, Erwin Schrödinger, Paul Dirac, and Wolfgang Pauli. Quantum mechanics has been a highly successful theory, but its interpretation has been a topic of heated debates due to its diverse and often contradictory nature. While most quantum physicists utilize the mathematical framework of the theory to make predictions, some physicists and philosophers aim to understand the epistemological and ontological nature of the entities studied. These attempts to understand the theory beyond pragmatic probabilistic predictions have led to various divergent interpretations. Quantum mechanics deals with strange phenomena that violate our common-sense understanding of nature, matter, and causality. Although the theory’s developers gave divergent ontological interpretations to its mathematical formalism, most of them were incompatible with a materialist ontology. Gustavo E. Romero [7] has studied the Copenhagen Interpretation’s idealistic flavor very well. Bohr, the leading advocate of the Copenhagen Interpretation, claimed that reality was not a property of the referents of quantum theory: “an independent reality, in the ordinary physical sense, can neither be ascribed to the phenomena nor to the agencies of observation” [12]. Heisenberg held that materialism was untenable: “The ontology of materialism rested upon the illusion that the kind of existence, the direct ‘actuality’ of the world around us, can be extrapolated into the atomic range. This extrapolation is impossible, however” [13]. Wolfgang Pauli interpreted the universe through the lens of Jungian mysticism [14]. Eugene Wigner, another notable quantum physicist, maintained that consciousness was a necessary element for the quantum theory: “It is not possible to formulate the laws of quantum mechanics in a fully consistent way without reference to the consciousness” [15].

Despite these anti-materialist interpretations of quantum phenomena, some early quantum mechanics developers held realist interpretations. Among them, Albert Einstein stands out. He fought against the idealistic and “spooky” interpretation of several quantum phenomena, but his classic interpretation of quantum phenomena was discarded by most of the quantum scientific community.

Quantum mechanics deals with specific physical systems called quantum systems. Some of their properties, such as spin or entanglement, cannot be found in any macroscopic entity or process in the universe. The states of a quantum system are represented by a mathematical function ψ(x) ∈ H called a wave function. Here, x represents the position of a point in Euclidean 3-dimensional space, and H stands for a Hilbert space. The wave function is a mathematical tool used to describe the quantum state of an isolated quantum system.

I will now briefly analyze some popular anti-materialistic interpretations of quantum mechanics. My main point is that approaches to quantum mechanics that are idealistic, “spooky”, or theological are baseless interpretations. On the other hand, philosophical materialism is a much better fit for quantum mechanics.

3. Are Quantum Systems Indeterministic?

With very few exceptions, throughout history, one of the key aspects of philosophical materialism has been ontological determinism [16]. This concept asserts that all events in the universe are governed by causation and can be rationally explained without any supernatural intervention. An example of this deterministic materialism can be found in the works of the Stoics, Spinoza, Baron d’Holbach, and Laplace. However, quantum physics has challenged this notion by demonstrating that, at the quantum level, there are phenomena, such as the decay of a muon, that do not have a cause. Furthermore, identical initial states of a quantum system, even with infinitely precise data according to the Laplacian ideal, can end randomly in different final states [17]. This ontological chance has nothing to do with sensitivity to the initial conditions and is therefore unrelated to chaos in its physical sense [11]. Many scholars have interpreted the stochastic nature of quantum matter as evidence of ontological indeterminism. This has been a source of criticism in the 20th century, particularly from Einstein, who was skeptical of the strange, seemingly “spooky” actions that occur at a distance in quantum mechanics.

The principle of sufficient reason and causality has been a fundamental tool for human beings to understand and explain natural phenomena. However, the discovery of certain quantum phenomena, such as electrons jumping to different orbitals and muons decaying, challenges our understanding of causation. Epistemologically, quantum mechanics has often been interpreted as indeterministic as it relies on probabilities to predict the behavior of quantum systems. These probabilities describe the likelihood of a quantum system transitioning from one state to another.

The Copenhagen interpretation of quantum mechanics explicitly supports ontological indeterminism due to the metaphysical randomness at the quantum level. However, as Gustavo E. Romero [7] has noted, the linearity of the dynamical equations of quantum mechanics implies that the theory is entirely deterministic. Therefore, the state of a non-interacting quantum system is wholly determined at any point in spacetime based on its initial conditions. But what occurs when a quantum system interacts with other physical realities of its environment? Although determined, quantum phenomena exhibit some properties that are not predetermined by their immediate past and environment. For instance, in scattering experiments, where particles are directed at a target with the same speed and direction, they can end up in different places, and physicists calculate the probability of this happening. Another example is an electron moving in a magnetic field, which can end up with its spin parallel or antiparallel to the external field with equal probabilities.

This indicates that quantum systems do not follow pre-determinism (i.e., classic Laplacian determinism), and there is space for contingency at the quantum level. However, it is essential to distinguish between pre-determinism and determinism in general. Predeterminism (or fatalism) asserts that contingency is an illusion, as everything happening in the universe is the inevitable outcome of previous conditions [18]. Quantum systems, like any other kind of material system, are deterministic but not pre-deterministic because their behavior, to begin with, is determined by the laws of physics. Determinism in general is about ontological legality, i.e., phenomena obeying laws [19]. Every quantum phenomenon is deterministic in a general sense because it is legal, that is, it obeys physical laws, such as the principle of energy conservation.

The ontological legality of quantum matter is unambiguously defined by physical laws that link quantum states to other quantum states, although not in a predetermined way when the quantum system interacts with other physical realities. There is no univocal legal connection between the initial and final states of a quantum system in many circumstances. For instance, when an excited atom emits energy, an atomic nucleus disintegrates, or when measuring a quantum property to obtain an eigenvalue [11]. But the stochastic nature of some quantum phenomena is legal and just demonstrates that predeterminism does not apply at the quantum level.

There are reasons to think that predeterminism does not work even at the macroscopic level. The macroscopic future could be partially open. The idea that everything is predetermined since eternity or the beginning of time, as the Stoics, Spinoza, d’Holbach, or Einstein believed, is more of a metaphysical speculation, a consequence of extrapolating a simplistic understanding of causality to the whole universe than a rigorous scientific or ontological claim [20]. Is there any scientific evidence to support the idea that the physical conditions of the Planck era, for example, predetermined events such as the assassination of Julius Caesar, the French Revolution, or me writing this paper? In both the microscopic and macroscopic scenarios, this partial contingency would be legal, i.e., deterministic.

To sum up, whether contingency is real or an illusion, as Spinoza or Einstein claimed, the ontology of the universe is deterministic as long as it is legal.

4. Is the Wave–Particle Duality a Violation of the Principle of Identity?

The ontological problem of identity in quantum objects has been a heated subject in the philosophy of quantum mechanics [21,22,23,24,25,26,27,28]. Specifically, the concept of wave–particle duality in quantum mechanics has been a hard nut to crack and, understandably, has received divergent interpretations in various ways. Quantum entities like light and electrons can display either particle-like or wave-like properties depending on the experimental conditions. In the 19th and early 20th centuries, scientists discovered that light behaves like a wave, but later experiments showed that it also has particle-like characteristics. Similarly, electrons were initially believed to act only as particles, but later experiments revealed their wavelike properties. The term “duality” was introduced to describe these seemingly contradictory behaviors.

Is the phenomenon of wave–particle duality proof that the logical principles of identity and no contradiction are invalid? The answer is no. Here, as with other important critiques of non-materialist interpretations of quantum mechanics, I follow Romero’s argumentation. The classic concept of wave–particle duality needs to be corrected. Quantum systems are not waves or particles but unique entities that cannot be classified as either. These systems can exhibit wave-like behavior under certain conditions and classical particle-like behavior under others, but the safest assumption according to our current knowledge is that they are essentially fields that exist throughout spacetime. The particles we observe are merely excitations of these fields. Therefore, subatomic entities, rather than vague objects [23,29], are sui generis entities that do not behave like classical particles or waves but rather display their sui generis properties [7].

Quantum field theory is a robust and reliable theory that has an exceptional ability to make accurate scientific predictions. It provides a unified view of all interactions except for gravity. In this theory, each field is considered an extended entity in spacetime. Although this is a topic of much debate, there are compelling scientific reasons to posit that particles are not elementary objects but rather excitations of the corresponding quantum field [30]. Quantum field theory studies particles as excited states of their underlying quantum fields, which are therefore more fundamental than the particles. For this theory, the most essential property of matter is energy, understood as the ontological feature of changing and producing changes. The energy density of the quantum field is well-defined in all reference frames and cannot be affected by a change of frame. More specifically, the invariants of the energy tensor associated with the field are conserved, although the specific components of the tensor in each reference system are not. This means that the fundamental components in the theory are the quantum fields 2 [31]. Since these fields are independent of subjects, mutable, interact with each other, and follow the fundamental laws of physics, such as the principle of energy conservation, we refer to them as material. Finally, the spacetime over which these fields exist is material as well because it also has energy, albeit with non-local distribution. And, in the ontology I follow, to have energy is the essential property of being material. Therefore, at the quantum level, there are two kinds of matter: fields and spacetime. Whether these two types of matter can be interconverted or studied as emergent phenomena of a prior reality is yet to be determined. As for now, scientific evidence suggests that spacetime is a more fundamental entity than quantum fields. Quantum fields require spacetime to exist, but the reverse does not seem to be true [5,6,7,32].

5. Is Consciousness Required for the Collapse of the Wave Function?

Scientists use the wave function to describe different properties of an isolated quantum system. The wave function, as a mathematical description of the quantum state of an isolated quantum system, is an epistemological artifact, not an ontological entity or process. Therefore, it should not be confused with the quantum system itself. The quantum state after a measurement is in an eigenstate corresponding to that measurement and the value measured. The collapse of the wave function occurs when a quantum system interacts with its physical environment, causing a superposition of multiple states to be reduced to a single eigenstate. Such an interaction is known as an “observation”. This observation links the wave function to classical “observables” such as position and momentum and is the essence of a measurement in quantum mechanics. Collapse and development are two ways quantum systems evolve over time. Collapse is a sudden and random change in state, while evolution is governed by the Schrödinger equation.

Despite its inner variants, the Copenhagen Interpretation of quantum mechanics implies ontological idealism by suggesting an inseparable connection between quantum mechanics and consciousness. This interpretation argues that consciousness causes the collapse of the state function. Another renowned quantum physicist, Eugene Wigner, believed that consciousness is an essential element of the theory and that it is impossible to formulate the laws of quantum mechanics without referencing consciousness. However, this interpretation is not a direct result of the theory itself. Neither quantum theory includes any variables that indicate mental properties, nor have any experiments confirmed that conscious experience is needed for any quantum phenomenon to occur [7,33,34].

Moving away from the idealistic flavor of the Copenhagen Interpretation, many physicists consider the wave function nowadays as the decoherence resulting from the interaction between a quantum system and its macrophysical environment, which need not be manned by a conscious experimentalist: state-function collapse is a purely physical process in which conscious life is not necessary. Disembodied minds cannot act upon microphysical systems, nor upon any other reality because they are just a contradictory fantasy! Mental processes are an emergent activity of some biological systems equipped with nervous systems. To begin with, a disembodied mind interacting with physical systems would violate the principle of energy conservation (for ontological arguments against the spiritualist hypostatization of the mind, see: Bueno [2], Bunge [19], Pérez-Jara [35].

To put it simply, the idealistic interpretation of the collapse of the wave function is the result of the confusion between a conscious observation and the interaction with an impersonal macrophysical environment.

6. Nonlocality and Quantum Entanglement: Spooky Action at a Distance?

Nonlocality is another quantum phenomenon that poses a constant headache for those who interpret quantum mechanics from a materialist perspective. The concept of locality is fundamental in physics and can be defined in various ways, such as by referencing Lorentz invariance or the principle that no signal can exceed the speed of light. Underlying the different definitions of locality is the assumption that action at a distance is impossible and that an object is affected only by its immediate surroundings. Thus, for one physical object to influence another, it must either directly contact it or indirectly through a series of other intermediate events. For instance, for a wave or particle to exert an influence, it must travel through the space between the two points, carrying the influence with it. A theory that abides by this principle is known as a “local theory”.

Action at a distance was the most challenging aspect of Newtonian mechanics, apart from Newton’s speculations about the role of God in the universe. However, Newton did not deny the possibility of unknown mechanisms explaining the apparent action at a distance between gravitating masses. He just stated that he did not hypothesize about them, saying, “hypotheses non fingo”.

In Newton’s words:

I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction.

[36].

After Newton introduced his theory of mechanics, Coulomb’s law seemed to have the same problem of action at a distance, which is one of the most recognizable features of magic. However, the development of field theories in physics during the 19th and early 20th centuries broke the spell of action at a distance. Despite this, the existence of quantum fields in quantum mechanics has not dispelled the phenomenon of nonlocality. Quantum nonlocality has been experimentally verified under various physical assumptions. It refers to the phenomenon where the measurement statistics of a multipartite quantum system do not allow for an interpretation compatible with local realism [37].

Quantum objects exhibit non-local features, which means they are correlated regardless of distance. The most notable example is quantum entanglement, a complex phenomenon that involves a mysterious connection between two quantum objects, regardless of the distance between them. This connection allows any changes to occur in one object to instantaneously affect the other. Despite being initially dismissed by Einstein as “spooky action at a distance”, the phenomenon of entanglement has since been proven as a real and fundamental aspect of quantum mechanics.

In 1935, Schrödinger introduced the term “entanglement” to describe a unique aspect of quantum mechanics that differentiates it from classical physics. This was in response to a renowned paper by Einstein, Boris Podolsky, and Nathan Rosen that claimed quantum physics was incomplete and required local hidden variables to avoid “spooky” interpretations of quantum phenomena.

The EPR argument deals with the idea that reality is made up of objects with physical properties, which interact locally with each other and can be discovered through scientific measurement [38]. This is how most people naturally see the world. Einstein’s theory of relativity also aligns with this understanding and states that nothing can affect anything else faster than the speed of light. However, the EPR argument argued that quantum physics, in its current state, cannot be reconciled with these concepts and therefore cannot support a theory that is compatible with both locality and realism. In other words, quantum physics was incomplete. Einstein suggested that scientists should look for a “deeper” theory of local reality to complete quantum physics. In 1964, physicist John S. Bell presented a theorem that challenged the EPR argument. Bell [39] also proposed an experiment that could demonstrate the non-local character of quantum mechanics. The first experiment based on Bell’s proposal was conducted by John Clauser and Stuart Freedman in 1972. This experiment was later improved and refined by Alain Aspect and Anton Zeilinger, which demonstrated the violation of Bell’s inequalities using distant detectors with photons [40]. Since then, many similar experiments, known as Bell tests, have been performed multiple times, consistently corroborating Bell’s theory [41]. The Kochen–Specker theorem complemented Bell’s theorem. While Bell’s theorem established nonlocality as a feature of any hidden variable theory that recovers the predictions of quantum mechanics, the Kochen–Specker theorem established contextuality as an inevitable feature of such theories [42].

Causality is a relation among events, not among things [6,17,43,44]. Causality occurs when an event in thing A triggers an event in thing B. The critical point is that causality implies a transfer of energy through the change in the state of a particular entity, which is not the case with quantum entanglement. Quantum entanglement is about correlations, not causal influence. Therefore, although it is a surprising and fascinating feature of matter that cannot be found at the macroscopic level, there is nothing “spooky” or magical about it [7,34,40,45]. It would be indeed spooky or magical if it implied a transfer of energy at a distance. However, when we determine the state of one component of the entangled system, the state of the other component does not change, meaning that no work is exerted on the second component, and no energy transfer occurs. The state of the second component does not go from state s1 to state s2; there is simply a specification of the system’s state [7].

Once an entangled state is formed, the system remains intertwined regardless of the spatial separation of the components. When we specify the state of the first component of an entangled pair, the state of the second component is also specified according to the system’s initial conditions. Once an interaction disrupts the entanglement, the components become separated, and correlations no longer exist. In this view, there is no action of one system component upon the other, only non-local correlations. Information cannot be transmitted faster than light through entanglement because any transmission requires a signal that should move at the speed of light. Every step in the process of quantum entanglement is compatible with ontological realism, which means a universe composed of physical systems and processes independent from human subjects 3 [46].

In summary, action at a distance does not exist in quantum mechanics, and scientists and philosophers who state otherwise confuse correlation with causal action. Quantum entanglement is a legal phenomenon that does not challenge a materialist view of reality 4 [47,48].

7. Do We Need God to Explain the Apparently Fine-Tuned Universe We Live in?

So far, I have analyzed how the main features of quantum matter are fully compatible with a materialist worldview, from stochastic processes to quantum entanglement. Idealistic and spooky views of quantum mechanics stem from incorrect philosophical assumptions, such as confusing disembodied minds with purely physical interactions or correlations with causation. While the previous sections are directly related to quantum mechanics, this section addresses an essential ontological problem that is partly intertwined with quantum mechanics and partly associated with other areas of physics. However, its importance is crucial for discussing idealistic or materialistic interpretations of quantum phenomena. This final challenge to materialism with regard to the interpretation of quantum mechanics is God. There has been a recent increase in theistic interpretations of physics that combine quantum mechanics with cosmology. These interpretations suggest that certain essential constants in the universe are finely tuned to allow life’s existence as we know it. Some of these constants are not related to quantum mechanics (such as the gravitational constant (G)), while others are, such as Planck’s constant (ℎ) and the electron charge. According to the hypothesis of the “fine-tuned universe”, these constants have specific values that allow for life to exist. If they were slightly different, life would be impossible. This suggests that they have been calculated by an immaterial mind which has designed the universe.

The argument that we can only explain the universe’s physical constants by a theistic interpretation is flawed for several reasons. First, it treats constants as variables. Second, this argument falls into a vicious circle of explanation. Third, it treats God as a non-omnipotent demiurge. Finally, it presupposes the ontological possibility of the ontotheological God, i.e., a disembodied absolute and immutable consciousness that exists beyond spacetime.

To hold that cosmic constants are variables and, therefore, could be otherwise is a begging of the following question: what happens if cosmic constants are brute facts or can only take a very limited number of values? To calculate the probabilities of life in the universe by assuming that cosmic constants can take all kinds of values is a baseless thought experiment. On the other hand, explaining human life and intelligence for the design of a God who is considered the plenitude of life and intelligence is a vicious circle. It means explaining A (life and conscious experience) by A (a mysterious entity bestowed with life and conscious experience). These vicious circles are unfortunately common in the history of Western metaphysics, at least since Plato attempted to explain the universe’s morphologies through the Forms contained in the ideal world. Thus, material trees are explained by the ideal Form of a tree, which is obviously a pseudoexplanation. My argument is that something very similar happens when theists attempt to explain human beings through an anthropomorphic God [35,49]

Finally, to treat God as a being submitted to the laws of physics contradicts the very concept of an all-powerful God. A real omnipotent God can violate any natural law, not just exceptionally by miracles, but by creating life in any possible cosmic context without having to calculate cosmic constants/variables [49]. This argument, in my opinion, is more powerful than claiming that we know, thanks to computer models, that life is also possible if we change all the constants of the universe at the same time and in the same proportion. While these models are very interesting, they do not question God’s omnipotence or the ontological possibility of an immaterial God.

There are powerful arguments to hold that a disembodied, infinite, absolute, and immutable consciousness (essential features of the ontotheological God) is a contradictory mosaic of concepts, i.e., a pseudo-idea. Baron d’Holbach convincingly argued in his work The System of Nature that the concept of the supreme God in Abrahamic religions is like a “patchwork” made up of pieces that do not fit together [50]. However, within the atheistic community, from Bertrand Russell to Richard Dawkins, via Anthony Flew and Mario Bunge, the most common position has been the notion that God is a possible entity but non-existent, like unicorns or other mythological creatures.

Only a minority of philosophical atheists have considered the idea that the supreme God cannot exist [51]. This minority tradition, in my opinion, is the most powerful one, and it is the one I follow. To put it in a nutshell, the constituent aspects of conscious experience, such as memories, desires, emotions, impulses, perceptions, and reasoning, inherently involve space, time, and bodily interactions. An immutable consciousness would not be able to engage in basic features of agency, such as making plans, processing information, or interacting with the external world. A perfect entity would not possess will because it would lack any needs or deficiencies. An infinitely expansive mind would essentially encompass the entire world, leading to pantheism. Such an infinite mind would render intentionality impossible. Omniscience is not compatible with the structural unpredictability shown by chaotic systems. Omnipotence and omniscience cannot coexist, as God would not be able to create unknowable realities. Omnibenevolence is not consistent with unnecessary suffering in the animal kingdom. In short, there are many contradictions to the Abrahamic idea of God. For further in-depth discussions on these topics, see Pérez-Jara [52], Bueno [53], and Romero et al. [16].

Sometimes, to avoid the ontological contradictions that the traditional God leads to, some authors use the design argument in an apparently less metaphysical way, appealing to aliens from another universe that created ours. This creation can be physical or a computer-generated artificial simulation in which we are trapped. These arguments are gratuitous and fall into a vicious circle like the theological one: to explain life through (an imaginary) life. To sum up, there is no evidence whatsoever in the cosmic constants of the universe at the quantum level to suggest that an immaterial mind has designed them. Furthermore, explaining life in general and human life in particular through an immaterial consciousness outside space and time that has meticulously calculated cosmic dimensions such as the Planck constant is not only gratuitous metaphysical speculation; it is also contradictory with the theological framework that bestows God with omnipotence and, therefore, the power to create life in any cosmic scenario, whatever the cosmic constants are.

8. Towards a Supra-Physical Understanding of the Universe

Although the sections above only provide a summary, their intention is to demonstrate that the peculiar characteristics of quantum matter do not pose a threat to a comprehensive materialistic perspective of reality, i.e., a perspective that rejects immaterial minds, God, or magic. However, an ontology must be consistent with all aspects of reality, not just one dimension of it. Philosophical materialism is often criticized for its inability to account for dimensions of reality that are not physical, such as mental processes or conceptual artifacts. In other words, there is a question about what happens beyond quantum matter and macrophysical matter. If physicalism cannot explain ontological systems and processes above the physical level, then rejecting idealistic, spiritualistic, and theological interpretations of physical matter may not be sufficient. Materialism should also be discarded. In this section, I will reject this claim.

Although materialism is a central concept in metaphysics and ontology, there is no universal agreement on the definition of matter. This term has varied interpretations, and philosophers have no consensus about whether the meaning of matter can be expanded beyond the physical [2,19]. Throughout history, our understanding of matter has been tied to some supposedly universal properties, including corporeity, mass, impenetrability, passivity, negativity, locality, and continuity. Though several philosophers and scientists have challenged some of these properties in the past, the discoveries of electromagnetic waves in the 19th century and quantum mechanics in the early 20th century brought about a radical revolution that fundamentally changed our views of matter. Despite this revolution, certain essential features of matter have remained, such as mutability and plurality, along with laws like the principle of conservation of energy and the importance of physical matter as the ontological foundation of chemical, biological, and mental processes. These features stand in opposition to traditional idealism and spiritualism, which hypostatize mental and social phenomena.

Philosophical materialism has also been defined in several ways and most philosophy dictionaries associate it with its most reductionistic and even eliminative versions. However, if we trace the concept back to ancient Greek philosophers and look at more recent interpretations, we can identify more comprehensive and richer forms of materialism. In the 20th century, non-reductionistic materialisms can be found in Roy Wood Sellars’s “evolutionary naturalism”, Gustavo Bueno’s “philosophical materialism”, and Mario Bunge’s “systemic materialism” (for a comprehensive discussion of non-reductionistic materialisms, see Romero et al. [16]).

In this paper, I follow a general definition of philosophical materialism that I have previously proposed [35,50]: I define philosophical materialism both positively (as matter understood as changeability and plurality) and negatively (as the rejection of disembodied minds and hypostatized ideas). Matter’s changeability implies energy as the most fundamental property known to us, while plurality entails a complex interplay of continuities and discontinuities, in which ontological determinism is an essential feature that dispels supernatural interpretations of natural phenomena —from miracles to magic. Ontological continuity and discontinuity are complementary notions. The interaction of both concepts allows for ontological plurality and connections in the universe. If there were no discontinuities in the universe, radical monism would be accurate, implying that diversity would be an illusion, as believed by philosophies such as Parmenides and the Vedanta thousands of years ago. Conversely, if there were no continuities in the universe, the universe itself would not exist, as there would not be any connections, causation, or interactions [35,54].

Philosophical materialism can be inclusive (i.e., emergentist) or exclusive (reductionistic or eliminativist). Inclusive materialism includes ontological realities (such as mental processes and complex sociocultural phenomena) that reductionistic materialism excludes through elimination or downward reductionism [16,19,50]. Reductionistic materialism can be easily identified with physicalism as the ontology or family of ontologies that claim that everything possible or real is either physical or reducible to physical matter. According to this worldview, the bottom of the universe (i.e., physical matter) is everything there is. However, physicalism’s main ontological claim is supported by a wrong assumption: ontological aggregationism. Ontological aggregationism consists of identifying the ontological nature or essence of something with its components. This implies downward reductionism. Philosophical systems are constructed from abstract representations, which are composed of brain processes, which are in turn composed of molecular processes, which are made of atomic interactions, and so on, down to subatomic particles, which are perturbations of quantum fields. Thus, all entities and processes in the universe, from black holes and galaxies to complex political and social organizations and exquisite forms of art, are made of quantum fields to the best of our knowledge. While this claim is true, it does not support physicalism. The reason is simple: being made of x is not the same as being x.

This is the essential feature behind the idea of emergence: the nature of something is not exhausted by the nature of its components. John Stuart Mill [55] clearly acknowledged this in the 19th century when analyzing chemical examples, such as the standard but mistaken identification between water and H₂O. Water itself is not just H₂O, as ice and steam are also made of H₂O but possess different characteristics. This is not trivial; biological systems (and therefore social and cultural systems) would not exist without water’s qualitative properties. The qualitative properties of things, as complex systems, depend not only on their composition, but also on their structure, mechanisms, and environment [19,43,56,57]. The interaction between these dimensions is what gives rise to qualitative novelties. These qualitative novelties, known as emergent properties, are characteristics of a system that are not present in its individual parts. The universe offers countless examples of emergent properties, such as the brightness of a star (not present in the star’s atoms), the self-repair capability of cells (not present in a cell’s molecules), human agency (not present in human anatomic parts), and many societal features that are not found in the individual members that compose that society.

Works of art, social systems, and living beings are composed of quantum matter, yet they qualitatively transcend the realm of quantum physics. We can say that they are supra-quantum realities due to their emergent properties and the fading of some characteristics that are key at the quantum level. For example, the ontological phenomena of replication and selection are not present at the quantum level; they only emerge at the biological, social, and cultural/artificial levels [44]. Without them, life and sociocultural systems would not exist. Conversely, biological or social entities do not possess spin or the ability to be entangled. When we move to a higher ontological level, new properties emerge, like replication and selection, while others, like spin and entanglement, fade. This ontological interplay of qualitative novelty/vanishing does not follow any known law. It is also important to note that this process of gaining new properties and losing others is not reciprocal. Although emergent complexity usually results in the loss of some specific properties of lower levels, the resulting emergent features are far more diverse and complex than those found in lower levels. Every ontological level gains qualitative density. Thus, even though electrons can cause catastrophic events, their capabilities are still quite limited compared to macro-physical systems such as computers or brains.

We can classify the various emerging material realities into different ontological levels. An ontological level is a collection of entities and processes that share certain properties in common [16,56]. So, for a non-reductionist worldview, we can differentiate between different types of matter based on the emergent level to which they belong. As a result, we can categorize matter into at least five types: physical, chemical, biological, social, and cultural/artificial. The molecular level, to which chemical matter belongs, has qualitative properties that are absent at the purely atomic and subatomic levels. The biological level, to which biotic matter belongs, has qualitative properties that are absent at the chemical level, and so on.

We can also distinguish different kinds of matter within each ontological level. Thus, macroscopic physical matter has qualitative properties that cannot be found at the quantum level, that is, in quantum matter. Interestingly, in the ontological phenomenon of emergence, while some properties from the lower level continue in the higher level (for instance, mass, present in atoms, molecules, cells, individuals, and social systems), other lower properties are lost. Thus, some properties of quantum matter, such as entanglement, are absent at higher ontological levels.

Now, we can better understand how inclusive materialism enriches the interplay of continuities and discontinuities that I have identified as one of matter’s essential features. We can observe ontological discontinuities throughout the universe, both horizontally (i.e., within each level of emergence: discontinuous processes in physical matter, chemical matter, biological matter, and so on) and vertically (i.e., between different levels of emergence: for instance, the irreducibility of biological systems to mere physical processes implies ontological discontinuities). The concept of a system already implies the interplay of continuity and discontinuity; continuity because nothing arises out of nothing, so the emergent properties of a system result from the system’s composition, structure, mechanism, and environment. And discontinuity because the emergent properties of a system are qualitatively irreducible to the parts of the system. And when downward or upward reductionism does not work, it is because there are ontological discontinuities.

It is in the context of emergent ontological levels that I discuss supra-physical matter in this paper. Chemical, biological, social, or artificial objects have physical properties and are made of physical entities and processes. However, because they possess qualitative properties that cannot be reduced to the purely physical level, we can refer to them as supra-physical realities, although they depend on physical matter for existence. This ontological irreducibility has an epistemological correlate: a physicist cannot explain biological processes, let’s say, complex social and cultural interactions. Of course, and similarly, we can also say that social systems are supra-chemical or supra-organic [43]. Since these expressions refer here to ontological levels of emergence, we could also say reciprocally, for instance, that chemical matter is infra-biological or infra-social because chemical processes are below biological and social processes. Even when chemical and biological matter co-evolve (for instance, some chemical compounds only exist thanks to certain biological processes: see Pérez-Jara [44]), the asymmetrical relation between them remains. Therefore, here, “supra” or “infra” do not mean at all more or less real, better or worse, or the like. These expressions refer to the ontological order in a hierarchical, asymmetrical (and therefore non-flat) universe.

Within this general approach, we can establish an ontological law stating that the more complex an object is, the scarcer we find it in the universe. For example, physical objects are more common than chemical objects, and chemical objects are more common than biological objects. Furthermore, biological organisms without mental processes are more common than those that possess them. The price of displaying qualitative ontological novelty is scarcity and growing precarity.

It is essential to clarify that by the term “scarcity”, I am referring to objects or processes and not properties. Physical objects or processes are far more abundant in the universe than sociocultural objects or processes. However, regarding ontological complexity, quantum systems or black holes have fewer properties than sociocultural systems. This leads to another ontological law: the more scarce an object is because of its ontological complexity (let’s say an organism equipped with a complex centralized nervous system), the richer it is in terms of irreducible properties or features.

Like the first abovementioned law, this is not an a priori law; it is a pattern of recurrence we observe while studying the complex interplay between sociocultural, biological, chemical, and physical matter. On the other hand, it is not merely empirical either. Higher emergent complexity requires many precarious conditions. For example, living organisms can emerge in narrow physical and chemical conditions—so narrow that they can quickly disappear. Of course, some physical entities (for instance, some unstable isotopes such as francium) are far more ephemeral than qualitatively far more complex entities (for instance, the city of Rome). But no sociocultural process or entity can aspire to last what many physical entities and processes do. And is this structural asymmetry what the second law refers to?

It is also important to note that there are plenty of more sciences than ontological levels. There are also sciences that study ontological dimensions that exist on different levels. Therefore, economics, sociology, cultural anthropology, political science, archaeology, and social psychology study dimensions of the biological, social, cultural, and artificial levels [58]. The higher an ontological level is, the more important it is to take an interdisciplinary approach, since social systems, for instance, have biological, chemical, and physical dimensions, but pure physical systems do not have social, chemical, or biological aspects. Conversely, less interdisciplinary study is necessary when dealing with lower ontological levels. The physical entities and processes studied by quantum mechanics do not encompass chemical, biological, social, or cultural/artificial dimensions. Just as the study of society and culture requires multiple disciplines, the study of quantum matter only requires quantum mechanics and the mathematical framework that constitutes its formalism.

9. On Vertical Causation as an Essential Feature of a Non-Flat Ontology

Supra-physical realities are not illusions; they are as real as quantum and classic levels of physical matter. It is just the product of a lousy ontology to say, for instance, that societies do not exist because there are only individuals or that individuals are just clouds of atoms. This is most clear when supra-physical realities influence physical realities. However, it may seem challenging to account for downward causation from a materialist ontology.

Quantum matter is postulated as the ontological basement of the universe and for materialistic approaches to reality in general. The interpretation of quantum mechanics that this paper has previously followed implies that quantum systems are objective real entities with specific properties that do not entail any idealistic, theological, or “spooky” approach to reality. Some quantum systems’ properties can be found in supra-quantum matter while others do not—it is the case of non-local correlations pointed out above. However, this is not strange since the interplay of qualitative novelty/fading is a constant in a non-flat ontological understanding of the universe.

A flat ontology is incompatible with the emergent complexity that matter shows in the universe, even at the physical level. Rejecting flat ontologies entails a discussion on vertical causation, i.e., causal relations between processes that belong to different mereological levels of ontological organization. Wholes ontologically constrained by their parts can be found everywhere: physical processes determine chemical reactions, chemical processes determine biological activities, and so on. This is what is known as upward causation. This form of upward causality is essential to understanding what I have called elsewhere “reality muzzle(s)” against the excesses of radical constructivism and relativism [35,59]. Human operations and constructed social and cultural artifacts (including scientific theories and models) are necessarily constrained, at least by physical, chemical, and biological realities. It is true (and this is the seed of truth of radical constructivism and relativism) that our knowledge of the external world is very far from immediate; instead, it is constructed, filtered, and subject to multiple cognitive and ideological distortions. However, no construction is a creation ex nihilo since it operates with previous materials that impose, like a muzzle, their ontological nature on the construction. Thanks to our ontological and epistemological dependence on external material reality, we can know that there are better and more accurate scientific constructions than others to partially know such reality and the place of human beings in it. Otherwise, we soon fast into self-contradictory epistemologies [35,49,60]. The ancient dream for ontological transparency in human knowledge is little more than an epistemological fairy tale. But no less false is the inverse epistemological myth of total ontological opacity [16]. Given the plurality of ontological muzzles, we can talk, at least, about physio-muzzles, chemo-muzzles, bio-muzzles, and socio-muzzles.

Because of its downward reductionism, physicalism fails to explain this ontological complexity. Physicalism is correct in denying non-physical or a-physical realities, such as the ontotheological God, supernatural spirits, or the Platonic heaven, but it fails when it also denies supra-physical realities, for only physical realities genuinely exist. According to the radical reductionistic approach of physicalism, only microscopic physical processes are truly real, and cells, mental processes, societies, or supercomputers would only be particular dynamic configurations of physical substances. Emergent properties of living beings and sociocultural systems would be pseudo-properties or (if the physicalist is generous) “properties by courtesy”, for they are totally reducible to physical processes 5. At most, we could only talk about “weak emergence”. However, radical reductionism is wrong even at the physical level, for condensed matter (such as crystals, superconductors, magnets, and liquids), for instance, have qualitative properties that cannot be reduced entirely to quantum processes [62]. Even in the purely physical domain, we find emergent properties, and therefore qualitative irreducibility. This qualitative irreducibility gains more ontological significance as we transition from the physical realm to other emergent levels, including the chemical, biological, social, and cultural/artificial. Despite its partial virtues, physicalism distorts our understanding of reality and our knowledge of it.

Physicalism entails a flat ontology, although, of course, not every flat ontology is physicalist. In Latour’s Actor-network Theory, for instance, relational assemblages provide the world’s main ontological structure [63]. Physical assemblages are just one kind, among many others, of relational realities. There are no asymmetrical relations between physical assemblages and non-physical physical assemblages. Everything, from ideas, empires, and living beings to black holes and quasars, is at the same ontological level. While this flexible methodology enables Latour and other thinkers to avoid both simplistic materialism and idealism, symmetrical relationism is a dangerous theoretical quicksand [35,60]. To ignore, minimize, or negate the structural and dynamic asymmetries that make up the universe prevents us from comprehending the universe itself. Scientific biological knowledge, for instance, is impossible without recognizing that biological processes imply physical and chemical processes, but not the other way around. Even within the same ontological level, numerous examples of asymmetries, such as dynamical instabilities and many horizontal causal processes, can be observed. In the following paragraphs, I will elaborate on this point.

In the complex theoretical jungle of non-flat ontologies, there seem to be opinions for all tastes: there are authors who hold that only “weak emergence”, but not “strong emergence”, is compatible with vertical causality [64], that “emergence and downward causation do not fit each other” [65], that we should reject the very concept of a layered reality, apparently needed for vertical causation [61], while others defend the possibility of emergence and vertical causation without either distinguishing levels or layers in reality [66], claim ontological emergence without vertical causation [67], or propose a “Relational-Horizontal Ontological Perspective” that would overcome the metaphysical puzzles that downward causation leads to [68,69].

There are better places for a detailed philosophical discussion around the complexities of emergence and non-flat ontologies. Suffice it to say that, in my approach, emergence entails a rejection of both symmetrism and relationism. Against substantialism, relations are key, sure. However, in the ontological phenomenon of emergence, the components of a system, along with its structure, mechanisms, and environment interactions, are all vital to explaining qualitative novelty [6,19,43,57].

Qualitative novelty implies asymmetrical relations. Critiques of the “layered” view of reality and the concept of vertical causality make sense for hypostatized views of the universe’s “levels”. But there are ways of understanding the asymmetrical structure of the universe without succumbing to Medusa’s Gaze, i.e., without petrifying any dimension of reality [35,59]. Chemical reactions can have physical effects (for instance, a rise in temperature), biological processes can change chemical compositions, and ideologies and cultural institutions can shape neurobiological processes. Of course, downward causation also happens within ontological levels (i.e., in sub-levels of organization). Macro-social systems shape micro-social systems such as families; families shape individuals; organ systems influence cells; cells determine their DNA sequences, combinations, and orders.

Only if we understand physical, chemical, biological, social, and artificial matter as overlapping strata in which causation closure happens can downward causation seem problematic or even impossible. However, the emergent properties of biotic realities, for instance, do not have absolute autonomy from chemical and physical processes. We can scientifically explain many phenomena without the need to go down to their components —but such phenomena would not exist without them. We can scientifically study economic crises or the behavior of bees and the so-called hive intelligence without analyzing the atoms that compose economic actors or bees.

If taken too seriously, the metaphors of strata, levels, and the layered pie are very misleading–like any other metaphor. For instance, in a mountain, a building, or a pie, the strata, the levels, or the layers have a degree of ontological independence that chemical compounds do not have from physical processes. Some of John Heil’s critiques of the notion of levels in an emergentist ontology come from this misunderstanding [61]. It is possible to consider the asymmetrical nature of physical, chemical, biological, social, and cultural matter without a wrong semantic view. Therefore, it is not true that abandoning the concept of “level” would determine the collapse of the whole emergence project. The notion of “ontological level” is not univocal; there are ways to understand it without falling into hypostatizing metaphysics. Finding a sound metaphor to illustrate the highly complex interplay of continuities, discontinuities, symmetries, and asymmetries that structure reality is complicated. However, along with other philosophers, we can consider an ontological level neither an autonomous thing nor something more or less real than the above or the below level, like in Neoplatonic metaphysics. If we take the ontological irreducibility of many processes in the universe seriously, we can consider an ontological level as a collection of things that share specific properties. Levels of organization, therefore, can be defined concerning a set of common properties [70].

In the ontological phenomenon of emergence, there is discontinuity (in the qualitative “jumps” from physics to society and culture) along with continuity. If emergence only implied discontinuity, we would find ourselves in creationism—and is this confusion, already mentioned, what leads many thinkers towards neophobic, aggregationist ontologies. If emergence only implied continuity, neophobic aggregationism would be right. Reductionism’s falsehood implies discontinuity; creationism’s falsehood implies continuity [35]. Therefore, there is no false dilemma between continuity and discontinuity; radical continuism would erase plurality and qualitative novelty in the universe, so even physicalism accepts horizontal discontinuities. Radical discontinuism, on the other hand, would make the universe impossible, for causality and any other interactions between things would not exist. The dynamic complex interplay of continuities and discontinuities prevents us from hypostatizing any dimension of the universe.

10. Physical Matter Does Not Predetermine What Goes on in the Universe

There is another possible objection to downward causation that we should consider. If we take upward causation for granted and see how physical processes determine, constrain, and muzzle chemical processes—which in turn muzzle biological processes and so on—should we not see supra-physical causal relations as epiphenomenal? If quantum physical processes determine the emergent properties of macrophysical processes and those of chemical, biological, and sociocultural processes, for instance, should we not see supra-physical causality as epiphenomenal, i.e., some kind of fatalistic mirror of physical causality? Some thinkers deny free will upon this base, for instance. According to them, if there is no freedom in the kingdom of physics (stochastic matter in the quantum matter is not “free”), there cannot be freedom in human psychology, for physical processes totally determine it. But this view ignores that some properties remain while others are lost in the organizational mereological complexity of things. Societies influence their members in a similar way as individuals’ actions and thoughts affect the chemical and physical properties of their bodies, i.e., through top-down causation. Furthermore, we know that ontological contingency exists at the known bottom of the universe (i.e., spacetime and quantum matter) due to the stochastic nature of quantum processes [20].

I will call the view that a top organizative level cannot influence its components upward (or down-top) fatalism. We do not need to start with physics to see this approach everywhere. Just let us recall radical biologicism in social science, according to which society and culture are epiphenomenal regarding biology—a view that continues to be pervasive today, from its most radical forms to its milder forms.

The ontological reality of downward causality should not prevent us from seeing that there is a structural asymmetry between upward and downward causation. That means the causal loop between upward and downward causation is not reciprocal. The overwhelming power of upward causation is undeniable. Let us suffice some drastic physical or chemical changes to kill every living being on Earth in the blink of an eye. Life is only possible under very narrow thermal, density, and gravitational conditions. But living beings, even with nuclear technology, do not have a similar power to alter stars, galaxies, or the general nature of the universe. Against the claims of radical social or epistemological constructivism, the forces of nature have a greater influence on us than we have on them (this is what I have called elsewhere reality’s muzzles: see Pérez-Jara [35,44]). But, despite the asymmetry between downward and upward causation, the reality of vertical two-way causation disproves epiphenomenalism, be it in the philosophy of matter (biotic matter as an epiphenomenon of physical matter), the philosophy of mind (mental processes as epiphenomena of electrochemical process in the brain), and the philosophy of culture (culture as an epiphenomenon of social structure or class struggle).

In metaphysics, an epiphenomenon is an effect that does not influence anything. If there were any epiphenomena, and, therefore, they did not interact with anything in the universe, we would never be able to know about them. However, there is undeniable empirical evidence of sociocultural processes influencing biological processes (such as through the Baldwin effect or epigenetic changes), biological processes influencing chemical processes (for instance, through fermentation), and chemical processes influencing physical processes (for example, chemical reactions that raise the temperature of a physical system).

The deniers of downward causation also embrace a self-contradictory epistemology. Knowledge and science entail intentional action, which is only possible if top-down causation is real [71,72]. Even when typing on a computer, they exhibit downward causation as their thoughts affect the flow of electrons on electronic circuits.

11. The Many Faces of Inclusive Materialism

Due to its monism and reductionism, physicalism’s central philosophical tenets seem easy to grasp. In contrast, the inclusive materialism I advocate is more complex. This epistemological complexity reflects reality’s complexity, which physicalism tries to mutilate or oversimplify. A couple of examples will suffice to illustrate this point.

As stated above, a materialistic worldview supported by updated science emphasizes both the emergence and eventual extinction of ontological novelties. We have no reason to believe that sempiternal realities (such as the human soul in Medieval Christianity) can exist. Therefore, we could say that “fading materialism” captures the essence of reality as well as “emergent materialism” since the disappearance of qualitative novelty, in reality, is as essential an ontological feature as the emergence of qualitative novelty. However, for an ontological novelty to fade, it must first exist. Therefore, emergent materialism seems a more useful concept than fading materialism. Although in the discussions about the immortality of the soul or any other element of the universe that someone pretends to hypostatize, fading or extinction materialism could be helpful concepts.

Similarly, and along with other non-reductionistic materialist philosophers, I emphasize the importance of both ontological continuity and ontological discontinuity. Unfortunately, reductionistic approaches tend to overlook discontinuities, which is why I also refer to my philosophical approach as “discontinuous materialism”. This term is meant to highlight the significance of the ontological plurality and novelty made possible by the principle of discontinuity [4,35,44,50,54,73,74].

My point with these examples is that expecting a single name to encompass all the fundamental ontological principles of non-reductionistic materialism would be unrealistic. Inclusive materialism can be called “scientific materialism” in contrast to pseudo-philosophical materialisms not informed by updated science. It stands for “systemic materialism”, as opposed to atomistic and holistic materialism, and supports “emergent materialism” instead of neophobic and reductionistic materialism. Furthermore, it advocates for “discontinuous materialism” over radical monist materialism. To sum up, the same philosophical approach can be given different names depending on the context of the discussion.

The problem is when the emphasis is consistently one-sided, such as on discontinuity or emergence. In order to avoid this conundrum, one possible solution I propose is to widen the syntagm of “inclusive materialism” that Mario Bunge [19,43,57] has sometimes used. Bunge talked about inclusive materialism because physicalism excludes the qualitative irreducibility of realities such as biological systems with mental processes and conceptual artifacts via downward reductionism or eliminativism. Following a similar thread, I propose to expand the meaning of inclusive materialism by expanding the features it actually includes: updated scientific knowledge, continuity and discontinuity, novelty and fading, symmetry and asymmetry, upward and downward causation, impermanence (of the universe’s contents), and the relative permanence of some ontological structures and mechanisms. This does not prevent us from using other names (“scientific materialism”, “discontinuous materialism”, “emergentist materialism”, or “systemic materialism”). But it presents inclusive materialism as a well-grounded philosophical approach with several faces—and all of them play an important role in our understanding of the universe.

12. Conclusions

The physicist N. David Mermin [75] once quipped about quantum mechanics, “New interpretations appear every year. None ever disappear”. This statement may seem an exaggeration, but the existing variety of interpretations of quantum mechanics are as striking as their mutual divergences. We can explain this through two main epistemological reasons. So far, quantum mechanics is a fundamental theory that cannot be derived from any more basic scientific theory. On the other hand, quantum mechanics studies invisible phenomena that are so far from our experienced world that contradict our intuitive and macroscopic notions of matter and causality.

Quantum mechanics’ mathematical formalism works as a Rorschach test in which different scientists and philosophers see divergent interpretations. Of course, many quantum scientists bypass the problem of the ontological interpretation of quantum mechanics mathematical formalism just by focusing on using the theory to describe and predict quantum phenomena. Making predictions in the laboratory through the mathematical tools of quantum mechanics is a laudable practical approach. Engaging in speculative philosophical debates seems unnecessary when we have scientific methods at our disposal. However, the reality is that scientists who do not consider the ontological interpretation of quantum mechanics are missing an essential aspect of their work. While they may still describe and predict certain phenomena, the question arises: which phenomena are they actually describing? It is impossible to avoid ontological assumptions when scientists try to understand the nature of what they are studying and predicting. This fact has been acknowledged by many quantum mechanics pioneers and other physicists up to the present day [34,45,76,77].

This paper has explored the main dead ends that idealistic interpretations of quantum phenomena lead to. In contrast to such approaches, I have defended a materialistic interpretation of quantum phenomena. However, common philosophical materialism is a reductionist and exclusive worldview. While it can interpret quantum phenomena more accurately than idealism, it fails to account for other domains of the universe, such as the ontological levels of emergence above physical matter. Even though these domains are made of quantum fields to the best of our knowledge, they cannot be ontologically reduced to them.

An ontological framework must be able to explain all known dimensions of the universe, not exclude some of them via downward reductionism or eliminativism. To overcome the false dilemma between idealism and reductionistic materialism (i.e., physicalism), I have proposed what, inspired by Bunge, I call inclusive materialism. Inclusive materialism is a pluralist and scientifically informed metaphysics that recognizes the ontological significance and qualitative irreducibility of emergent phenomena, such as mental processes and conceptual artifacts, without hypostatizing them as ontological idealisms do.

From this ontological framework, I have defended the ontological interpretation of particles as perturbations of quantum fields. We can better understand quarks, leptons, and other elemental particles as modes of existence of those quantum fields. The mystery surrounding the wave function vanishes when we consider that it is an epistemological artifact, not an ontological entity; the wave function’s ontological reference is a quantum system, which is always independent of any observers and does not violate any of the basic tenets of philosophical materialism—such as energy conservation, mutability, plurality, and the rejection of spiritualism and idealism. The discrete character of quantum fields’ properties does not entail any mystery for inclusive materialism, which emphasizes the rich interplay of discontinuities and continuities, symmetries and asymmetries that structure reality. Analogously, other aspects of quantum mechanics, such as non-local correlations or the stochastic character of quantum phenomena, are incompatible with classical mechanics and 19th-century materialism but not with an updated, scientifically informed philosophical materialism. From a pluralist ontology, it is not a mystery that quantum systems possess properties that are significantly different from other material systems. We can find similar phenomena at any ontological level that asymmetrically structures the universe. Biological systems, for instance, have properties that cannot be found in social systems.

Of course, although from a materialistic interpretation of quantum mechanics, we can avoid the dead ends idealistic and spiritualistic interpretations lead to, there are many open problems to be considered for inclusive materialism. If systems are always composed of parts with a structure and mechanisms, why call elemental particles such as leptons or quarks systems? If the ontological nature of quantum systems is largely unknown, even if we reject local hidden variables, can there be some hidden mechanisms that explain non-local correlations or the stochastic nature of quantum phenomena, or are they “brute facts”, i.e., dimensions of reality’s primordial facticity? Will we ever know if quantum fields are part of reality’s primordial facticity or if they, along with spacetime, can be deduced from more primitive ontological realities?

It is a trope to say that from mental and social processes to invisible matter, most of our ancestors’ classic views of the universe have been shattered to pieces by modern sciences. And, of course, modern sciences, from quantum mechanics to cognitive neuroscience, have shattered many of our traditional, commonsensical views of the human being and nature. However, the damage that science has done to millennial approaches to reality is less radical than many would like to make us believe. Spanish philosopher Jesús Mosterín is wrong when he says that classic philosophical anthropology and ontology are blind because they unknow the theory of evolution or modern physics. Buddha’s ontological critique of substances and his claim that everything is impermanent (i.e., mutable) and co-dependent is today as accurate as thousands of years ago. We could say something similar about many theories from classic philosophers, from Greek thinkers to Spinoza, d’Holbach, or Schopenhauer. Of course, classic philosophical theories must be updated and corrected to align with our current scientific and philosophical knowledge. Nonetheless, we can still learn from them.

However, it is also true that certain scientific theories have (or should have) modified our understanding of the universe forever. Among these sciences, quantum mechanics stands out in our comprehension of what many call the basement of the universe. Downward reductionism always has a seed of truth: everything in the universe is indeed made of physical matter. However, we and our surroundings are not just quantum fields. That claim would imply falling again into the rabbit hole of metaphysical aggregationism. We are made of but are more than quantum fields. This is a millennial wisdom. Aristotle [78] already stated that things are more than the mere aggregate of their parts. Although (as far as we know) quantum matter is the most general ontological dimension of the universe along with spacetime, quantum mechanics only provides a limited understanding of the universe.

To summarize, we live not only in a supra-quantum world but also in a supra-physical world. And this does not deny philosophical materialism but enriches it.