The nature of consciousness represents perhaps the most profound existential enigma. Its significance to our lived experience is undeniable; yet, a definitive understanding remains elusive, with no widespread consensus among experts.
A significant hurdle to progress often lies in the tendency for specialists to become entrenched in singular theoretical frameworks, inadvertently overlooking alternative explanations that could prove fruitful. My approach, however, embraces the vast spectrum of consciousness theories spanning science, philosophy, and religion, provided they are grounded in rigorous argumentation. Over many years, this has allowed me to navigate and meticulously map over 350 distinct theories, charting them onto a comprehensive “landscape” that I aim to guide you through.
From strict materialism, which posits only physical states as real, to idealism, which asserts the primacy of mental states, and all the nuanced positions in between, the scope of this exploration quickly reveals the magnitude of what is at stake. The chosen perspective on consciousness fundamentally shapes one’s core beliefs about the world. This includes foundational views on the existence of free will, the possibility of an afterlife, and the potential for artificial intelligence to achieve genuine awareness.
Navigating the Diverse Terrain of Conscious Thought
The act of mapping this intellectual territory inspires awe, not only at the sheer volume of proposed theories but also at the astonishingly varied scales and contexts in which the phenomenon of consciousness is theorized to manifest. Neuroscientists frequently presume that experience arises from the intricate firing of neurons within the brain. However, numerous alternative theories exist, some positing consciousness as a fundamental aspect of reality, while others suggest that the physical world itself is merely an illusion. At the most granular level, questions arise: does consciousness emerge with the collapse of quantum wavefunctions into concrete reality? Conversely, on the grandest cosmic scales, is the universe itself imbued with some form of consciousness?
Defining the Core Question: What is Consciousness?
To begin to grasp the essence of consciousness, it is crucial to delineate the specific inquiry being posed. As artificial intelligence pioneer Marvin Minsky observed, “consciousness” is often a “suitcase term”—a repository for a multitude of related yet distinct concepts like perception, attention, wakefulness, memory, emotion, and intelligence. My own focus bypasses these. Instead, I am concerned with “phenomenal consciousness”: the subjective, internal sense of “what it’s like” to experience something, the private qualitative feelings. This encompasses the visual impression of a newborn daughter swaddled in blankets, the auditory experience of Mahler’s Second Symphony, or the olfactory sensation of garlic sautéing in olive oil. These interior subjective experiences are known as “qualia,” and they lie at the heart of the current conundrum.
My personal engagement with this profound question began in adolescence, culminating in doctoral research in brain science at UCLA during the mid-1960s. At that time, the genesis of consciousness was not a widely recognized or approachable area of scientific inquiry. More recently, through my role as creator and host of the public television series and digital platform Closer to Truth, I have had the privilege of discussing consciousness with over 200 leading scientists and philosophers across nearly three decades.
This extensive engagement has driven my endeavor to represent the full scope of human discovery, contemplation, and imagination concerning consciousness within this conceptual landscape. In an open-source, peer-reviewed publication last year, I compiled established theories alongside less recognized ones that exhibit originality, rationality, coherence, and – admittedly – a unique appeal. In collaboration with physicist and neuroscientist Àlex Gómez-Marín, digital strategist D.J. Smith, information designer Deniz Cem Önduygu, and editors Sean Slocum and Sandra Derksen, this initiative subsequently evolved into an interactive, comprehensive online resource: The Landscape of Consciousness. While some of the hundreds of theories we have gathered might appear unconventional, all underscore humanity’s persistent drive to comprehend the mind and apprehend reality. My hope is that, whatever its true nature, consciousness finds its place somewhere, somehow, someway within this conceptual map (refer to the Landscape of Consciousness map).
Fundamental Divisions: Dualism vs. Monism
The prevailing assertion among most neuroscientists is that consciousness is an exclusive product of the brain, emerging from the complex interplay of neural impulses and neurochemical activity. Yet, even as our understanding of brain biology expands, a persistent question remains: can physical states ever fully account for mental states? Philosopher David Chalmers famously termed this the “hard problem” of consciousness. Its obstinacy leads us to pivotal bifurcations within the theoretical landscape.
The initial crucial distinction lies in whether a theory is dualist or monist. Dualism, a concept largely avoided by contemporary physical scientists, proposes that the mental and the physical are two fundamentally distinct substances, neither reducible to the other. Traditional Abrahamic religions, for example, posit the existence of a “soul” alongside the physical body or brain. In contrast, monism contends that reality, in all its diverse manifestations, is ultimately composed of a single fundamental essence. Philosopher Bertrand Russell suggested that a unified set of properties underlies both consciousness and the fundamental constituents of the physical world.
Monistic Frameworks: Materialism and Idealism
Two prominent forms of monism occupy opposite ends of this theoretical spectrum. Materialism maintains that only entities governed by the laws of physics are real, thus requiring mental states to be entirely explained by physical processes. Conversely, idealism asserts that the mental is primary, with the physical world being derived from it. Under this view, physical reality could be understood as a manifestation of a universal mind. For instance, many Hindu traditions consider consciousness as the ultimate reality, and the physical world as a mere illusion.
Positioned somewhere between materialism, dualism, and idealism is panpsychism, the notion that the fundamental constituents of the physical world—whether fields or particles—are imbued with a form of awareness or proto-consciousness.
Conformist and Non-Conformist Physical Theories
A second critical division separating these categories of consciousness theories concerns their adherence to or departure from established physical laws and neurobiological principles. Theories that align with the classical understanding of physics and neuroscience often view the brain as operating akin to a computer, with consciousness emerging from complex feedback loops among neurons. These are considered conformist theories. In contrast, non-conformist theories, such as those positing information as a fundamental property of reality, operate beyond the conventional frameworks of scientific inquiry into consciousness. Giulio Tononi’s integrated information theory, for example, regards information as an intrinsic aspect of existence and equates consciousness with the causal power structure inherent within that information.
This analytical approach has enabled the categorization of the consciousness landscape into 10 broad domains, generally arranged from the most physicalist to the most non-physicalist. At one extreme, another category encompasses theories influenced by parapsychological phenomena, including near-death experiences, and altered states of consciousness, such as those induced by meditation or psychedelics. I lay no claim to a definitive or superior perspective on these categorizations; alternative organizational schemes are plausible, and the precise placement of certain theories remains a subject of ongoing discussion.
Nevertheless, these categories provide a foundational structure for further exploration. At the subsequent branching point, we can inquire: is consciousness fundamental and primordial, or is it an incidental byproduct derived from another source?
The Primordial or Derivative Nature of Consciousness
If consciousness is deemed fundamental and primordial, it cannot be entirely reduced to deeper explanatory levels. While partial explanations might be possible, certain aspects of our subjective experience would inherently resist modeling through biology, chemistry, or physics alone. All dualist, panpsychist, and idealist theories share the premise that while we can investigate the biological correlates of consciousness by studying the brain, this approach will never yield a complete understanding. In essence, there are inherent limitations to what the scientific method can reveal.
Conversely, if consciousness is considered accidental and derivative, the path forward suggests further distinctions. Is consciousness real, or is it an elaborate illusion? Though counterintuitive, arguments are made suggesting that consciousness is a cognitive trick. If this is the case, the consciousness conundrum effectively dissolves, or at least diminishes in significance. Philosopher Keith Frankish’s concept of “illusionism,” for instance, posits that our subjective experience of qualia is not what it appears to be; qualia are not intrinsic, fundamental features of the mind but rather brain-generated impressions.
Furthermore, if consciousness is real yet not fundamental, it is most likely emergent. Emergence describes the phenomenon wherein higher-level properties of a system, such as consciousness, arise from the complex interactions of its lower-level components. Water, for example, is wet, but individual water molecules are not. The process by which numerous water molecules combine to achieve wetness can be modeled, characterizing this as “weak” emergence, which remains amenable to complete scientific explanation. Typically, materialist theories of consciousness tend towards weak emergence. On the other hand, if consciousness is “strongly emergent”—as opposed to weakly emergent—it would invariably elude reductive physical explanation. Many theories falling into this category are classified as “non-reductive physicalism.”
Cosmic Consciousness and the Universe’s Self-Awareness
Could there exist a middle ground, where consciousness was not fundamental initially but, upon evolving and emerging, becomes an inevitable aspect of the universe, rather than a mere cosmic accident? Some theories propose that the universe possesses an inherent tendency towards self-awareness. Physicist Paul Davies, for example, suggests that quantum mechanics, wherein observers appear to distill current reality from a multitude of past possibilities, offers a potential mechanism. This idea, building on the work of physicist John Wheeler, posits that if consciousness eventually pervades the entire universe, future observers could influence past events, extending back to the Big Bang, thus bestowing consciousness with genuine cosmic significance. However, many theories embracing this radical concept extend beyond purely physical explanations. Theologian and paleontologist Teilhard de Chardin, for instance, envisioned the evolution of consciousness as a foundational element of a grand cosmic system.
Some of these concepts may sound extraordinary, and many are not amenable to experimental verification. Nevertheless, they remain coherent theories, supported by some thinkers and at least considered plausible by others. The sheer diversity of these perspectives becomes evident when mapping the 350-plus theories from the most materialist to the most idealist, and across the vast scales where consciousness is theorized to exist—as illustrated on the Landscape of Consciousness website.
Despite this breadth, materialism, which rigorously adheres to the scientific method, constitutes the most extensive category, encompassing nearly half of the over 350 theories within 12 distinct subcategories. This prevalence is unsurprising, as there are more avenues for formulating consciousness through physical models than through non-physical ones. The necessity for innovation is particularly pronounced within materialist theories seeking to address the enduring challenge of how the brain generates subjective experience. One neurobiological theory suggests that a mental state becomes conscious when it secures competitive access to a global workspace within the brain, which then disseminates this state to other brain regions. In contrast, electromagnetic field theories propose that consciousness is either identical to or derived from patterns of electrical currents coursing through the brain.
The Landscape of Consciousness is not merely a collection for casual observation of this bewildering array of theories; it serves as a conceptual laboratory for investigating profound questions about existence itself.
Can Artificial Intelligence Achieve Consciousness?
Consider the fervent debate surrounding the potential for artificial intelligence (AI) to attain consciousness (AIC). This question cannot be meaningfully understood, let alone resolved, without first clarifying the theoretical framework or category of consciousness being assumed. Moreover, given the considerable difficulty in devising a definitive test that distinguishes genuine AI awareness from mere simulation, assessing the plausibility of AIC through these different theoretical lenses is particularly insightful.
The majority of AI experts operate within a materialist framework, typically subscribing to computational functionalism. This view posits that the brain and its outputs, including consciousness, are inherently computational. Consequently, if the underlying function is accurately replicated, the output—consciousness—will also be reproduced, irrespective of whether this occurs within biological neurons or silicon-based computer chips. Other materialist perspectives, however, place a premium on biological life itself. Embodied and enactive theories, for instance, propose that mind arises from the dynamic interplay between the brain, the body, and the surrounding environment. In this context, the engagement of physical life forms with their surroundings becomes the crucial element for the emergence of consciousness.
Ultimately, from a materialist standpoint, the outcome concerning AIC remains consistent: it is considered inevitable. The primary discrepancies lie in the specific pathways involved and the projected timelines. If computational functionalism holds true, the challenge is identifying the relevant functions, suggesting a shorter timeframe. If biological life is deemed a prerequisite, then the artificial creation and manipulation of life forms become necessary, extending the timeline considerably.
Indeed, across most theoretical categories of consciousness, AIC can be viewed as a technical challenge of one kind or another, though the inherent complexity is frequently underestimated. For theories grounded in quantum mechanics, AIC also appears highly probable, with the development of quantum computers potentially accelerating the realization of this outcome. Even within panpsychist frameworks, where consciousness is considered an intrinsic aspect of reality’s fabric, AIC is likely. While the precise mechanisms for combining these micro-experiences into macro-minds remain unknown, there is no fundamental principle that should preclude their identification and replication.
The sole significant exception to the general likelihood of AIC arises within dualist theoretical frameworks. The postulation of a radically distinct, non-physical substance would, in almost all cases, present an insurmountable barrier to achieving artificial consciousness, regardless of technological advancement.
The Quest for Virtual Immortality
Similar reasoning applies to the prospect of virtual immortality, which necessitates the creation of a persistent, first-person digital representation of our minds capable of surviving biological death. However, virtual immortality represents a challenge at least one step beyond AI consciousness and appears more remote, primarily due to the significantly more daunting technological mastery required. Virtual immortality involves replicating the unique consciousness of a specific individual, encompassing countless qualities that neuroscientists are only beginning to delineate. In contrast, AIC could manifest in a multitude of forms.
Yet, virtual immortality is not the sole proposed solution to humanity’s enduring aspiration for survival beyond death. It is conceivable that individual consciousness could persist independent of any physical brain or body. According to dualism, some form of life after death is virtually certain, as individual consciousness is considered a non-physical substance that endures. Within idealism, even though reality is fundamentally mental, an individual’s consciousness might not remain static; it could merge or become indistinguishable from a grander cosmic consciousness upon death, or perhaps undergo reincarnation, as suggested by some Eastern traditions. Conversely, materialism renders the natural survival of consciousness post-mortem highly improbable, as it would presumably disintegrate with our biological brains. This stark reality compels some materialists to pursue the goal of virtual immortality.
Thus, while one may select a preferred theoretical framework, it is important to recognize that the implications are not equally optional. Furthermore, the freedom to make such a choice might not be absolute. This is because these theoretical categories also carry significant weight in the contemplation of free will. By “free will,” I refer to the “libertarian” sense in which certain human choices are not predetermined by past states or laws; we genuinely possess the capacity to have acted differently. Materialist theories generally deem this form of free will improbable, citing the predictable nature of physical laws, where every physical effect has a prior physical cause. Free will becomes more plausible within quantum theories of consciousness, as consciousness could potentially harness the vast potential of quantum phenomena, such as superposition and entanglement, which are not yet fully comprehended. And, for those holding an idealist view where the mental influences the physical, physical states cannot constrain mental states, thus affording near certainty of the freedom to chart one’s future course as desired.
My sole request is for the recognition that any accepted theory must align with what philosophers term an “identity theory.” This principle states that if the cause of consciousness is removed, then consciousness itself is also lost—analogous to how removing the “Morning Star” also removes the “Evening Star,” as both refer to Venus. In other words, in every sentient being, a specific entity inherently *is* consciousness.
The Potential of Quantum Computing in Consciousness Research
Hartmut Neven, the director of Google’s Quantum AI lab, has expressed interest in entangling human brains with quantum processors to investigate theories suggesting consciousness involves quantum phenomena.
I have developed a deep appreciation for this expansive array of theories, viewing consciousness as the paramount question of existence, irrespective of its ultimate resolution. If the fundamental nature of reality hinges on the distinction between purely physical and non-physical realms, then consciousness likely plays a decisive role in shaping that reality. Consequently, I maintain an open mind, eschewing restrictive adherence to favored theories or conventional modes of thought.
To be candid, my lifelong inquiry into consciousness has not been solely driven by rigorous science or detached philosophy. Since my teenage years, a less rational, persistent thought has occupied my mind: “Should a being capable of perceiving eternity be denied it?”
However, I do not deceive myself.
The Landscape of Consciousness website offers access to over 350 theories concerning consciousness through five distinct navigational methods: Landscape Grid, Landscape Categories, All Landscape Theories, Landscape Map, and Interactive Visualizations. The Landscape of Consciousness is a perpetually evolving project, a work in progress.