Donald Hoffman: Reality is an Illusion - How Evolution Hid the Truth | Lex Fridman Podcast

updated 29 Aug 2023

Donald Hoffman is a distinguished cognitive psychologist and professor of cognitive science at the University of California, Irvine. He is recognized for his groundbreaking ideas about the nature of consciousness and reality. Hoffman's research challenges conventional beliefs, proposing that our perception of reality is shaped by a "user interface" that hides the true nature of the world. His work has led to intriguing discussions about the fundamental nature of consciousness and its role in shaping our experiences.

Donald Hoffman: Reality is an Illusion - How Evolution Hid the Truth | Lex Fridman Podcast #293

The Case Against Reality

  1. The Case Against Reality: Donald Hoffman argues that what we perceive with our senses is not a true representation or even an abstraction of objective reality. He claims that our perceptions are completely detached from objective reality.

  2. Evolution and Sensory Systems: Hoffman's argument is based on the theorem of evolution by natural selection. He and his team asked whether natural selection would shape sensory systems to perceive true properties of objective reality. Surprisingly, they found that the probability of this is precisely zero for any generic structure of reality.

  3. Purpose of Perception: According to Hoffman, our sensory systems have evolved not to perceive the truth of reality, but rather to guide adaptive behavior. The focus is on perceiving what's necessary for survival and reproduction, rather than revealing the objective truth.

  4. Fitness vs. Truth: The evolutionary process does not prioritize truth; it prioritizes fitness. This means that adaptive behavior and reproductive success are more important than having an accurate perception of reality. Fitness does not necessarily have to be connected to truth.

  5. Mathematical Basis: Hoffman's argument is grounded in mathematical theories such as evolutionary game theory, evolutionary graph theory, and genetic algorithms. He presents several theorems and proofs to support his claim that the relationship between perception and reality is detached.

  6. Exception for Probability Measures: One exception to the detachment of perception from reality is related to probability measures. For scientific theories to be meaningful, there needs to be a measurable map between reality and our perceptions. However, this map could collapse information and be complex, but it still needs to preserve sigma algebras.

  7. Relationship Between Perception and Reality: Hoffman emphasizes that the mapping between our perceptions and objective reality is not one of direct correspondence. Instead, our perceptions guide adaptive behavior and can hide the complexity of reality, much like a user interface hides the intricate workings of a computer.

  8. Physicists' Perspective: Hoffman draws parallels between his ideas and developments in physics. Physicists are increasingly considering that space-time might not be fundamental, which challenges our traditional understanding of reality. These new discoveries from physics and evolution have emerged in the last two decades and are changing the way we think about reality.


  1. Space-Time is Doomed:

  2. Evolutionary Interface:

  3. Detachment from Objective Reality:

  4. Physics Beyond Space-Time:

  5. Interface and Reality Mapping:

  6. Role of Reductionism:

  7. Implications for Consciousness:

  8. Limits of Scientific Theories:

  9. Evolutionary Psychology and Financial Systems:

  10. Job Security for Scientists:


  1. Reductionism and Space-Time: Reductionism, the approach of explaining complex phenomena by breaking them down into simpler parts, is questioned in the context of space-time. Reductionism assumes that understanding smaller components will lead to understanding the whole. However, space-time itself might not be a fundamental concept, and theories might emerge beyond it.

  2. Scientific Explanation vs. Reductionist Explanation: Scientific explanations involve understanding and formulating principles, not necessarily breaking down to smaller components. Einstein's theories, such as special relativity and gravity, introduced concepts that were not derived from smaller-scale components but were based on deep principles.

  3. Exploring Beyond Space-Time: To advance beyond the theories of space-time, researchers need to think outside the space-time framework. This might involve seeking new models, such as cellular automata, which could provide insights into the nature of reality that space-time theories cannot.

  4. Nature of Dynamics and Causality: Going beyond space-time might require redefining concepts like dynamics and causality. The nature of these concepts could differ in a framework that transcends space-time.

  5. Understanding the Mind and Reality: The discussion delves into understanding consciousness, perception, and how the human mind attempts to grasp reality. The limitations of understanding microprocessors through neuroscience are highlighted, suggesting that similar limitations might apply to understanding the mind and reality.

  6. Depth of Understanding and Infinite Exploration: The concept of reaching the "bottom" of understanding reality is challenged. It's proposed that as we delve deeper into understanding, we might find that there's always another layer to explore. This endless exploration could be a fundamental aspect of our pursuit of knowledge.

  7. Concept of Reality and Intuition: The idea that the human mind might be capable of intuiting deeper truths about reality is discussed. This could involve reaching a level of understanding that transcends the limitations of language and concepts.

  8. Limitations of Scientific Pursuit: The possibility that scientific exploration might reach a point where it becomes less fruitful is considered. As we understand the limitations of our understanding, our focus might shift from exploration to appreciating the present moment and experiences.

  9. Impact of Theories Beyond Space-Time: Theories that go beyond space-time might open up new possibilities for exploration and discovery. For instance, the ability to bypass space-time for travel could revolutionize our approach to space exploration.

  10. Balancing Being and Exploration: The idea that a balance between non-conceptual being and exploration could drive scientific progress is proposed. Insights obtained from non-conceptual states might be integrated into conceptual frameworks to advance understanding.

Overall, the discussion challenges conventional views of reductionism, space-time, and scientific exploration, while emphasizing the potential for a deeper understanding of reality and the balance between exploration and being.

Evolutionary Game Theory

  1. Evolutionary Game Theory: The discussion begins with a focus on evolutionary game theory, which explores how organisms' behavior and strategies evolve over time in response to competition and cooperation. This theory provides a framework for understanding how different strategies can emerge and persist within a population based on fitness payoffs.

  2. Deviation from Reality: One of the central themes is the idea that our perceptions and sensory systems may not accurately represent the true nature of reality. The conversation raises questions about when and how humans, and other organisms, may deviate from perceiving reality as it is. The discussion explores whether this deviation is more pronounced in simpler organisms or if it occurs as intelligence and consciousness evolve.

  3. Interface and Perception: The participants discuss the concept of the interface between individuals and reality. They suggest that our perception of reality is akin to an interface that simplifies complex information into a usable form. This interface may not represent reality faithfully but is instead tailored to provide information that is relevant to survival and reproduction.

  4. Role of Fitness Functions: Hoffman explains that evolutionary game theory assumes the existence of fitness payoffs as a tool to study how strategies evolve. However, he acknowledges that the origin of fitness functions and the deeper mechanisms behind them remain open questions.

  5. Limits of Models: The conversation touches on the limitations of models and simulations, especially in the context of game theory and economics. It's discussed how oversimplifications in models can lead to flawed conclusions, emphasizing the importance of critical evaluation and openness to refining theories.

  6. Consciousness and Reality: The participants explore the connection between consciousness and reality. Hoffman presents a hypothesis that our perception of the world is an interface that doesn't necessarily reflect the underlying reality accurately. He suggests that even seemingly inanimate objects could potentially possess some form of consciousness or deeper reality beyond our current interface.

  7. Living vs. Non-Living: The distinction between living and non-living entities is explored as an important factor in evolution. The emergence of life and death, along with the ability to adapt and evolve, is seen as a significant component of natural selection.

  8. Complexity and Portals: The discussion delves into the idea that more complex organisms might create better "portals" to understanding each other's consciousness. More complex organisms may possess the ability to create more accurate models of other individuals' experiences and thoughts, leading to a deeper level of communication.

  9. Communication and Cooperation: The participants discuss communication and cooperation among organisms. They mention signaling games and language evolution as areas where game theory can help explain how individuals coordinate and communicate effectively.

  10. Deeper Reality: Hoffman introduces the concept of a "deeper reality" that underlies our perceptual interface. This idea suggests that the true nature of reality might be different from what our senses perceive, and that our current interface is just a simplified representation.

Overall, the discussion covers a range of thought-provoking topics related to perception, evolution, consciousness, and the nature of reality, inviting listeners to contemplate the complexities and mysteries of these subjects.

Conciousness Part I

  1. The Nature of Consciousness: The conversation begins with a focus on consciousness, exploring its role in human experience and the challenges in understanding it.

  2. Mainstream Approaches to Consciousness: The prevailing view in mainstream science is that consciousness arises from complex arrangements of matter, such as neurons. Various theories attempt to explain how certain functional properties of matter could lead to conscious experiences. These theories range from quantum collapse in microtubules to integrated information theory.

  3. Fundamental Assumptions: Hoffman challenges the assumptions underlying these mainstream theories. He suggests that spacetime and matter are not fundamental, as most theories assume. Instead, he proposes that consciousness is fundamental, and our understanding of spacetime and matter arises from consciousness rather than the other way around.

  4. Space-Time's Non-Fundamentality: Hoffman compares the historical shift from earth-air-fire-water to the discovery of fundamental particles and proposes that spacetime itself is not fundamental. He states that space-time is a data structure that consciousness generates and projects into.

  5. Conscious Agent Networks: Hoffman presents the idea of conscious agent networks. He defines conscious agents as generators of conscious experiences and suggests that interactions between these agents lead to the emergence of space-time and the physical world. These agents interact probabilistically, creating a network-like structure of experiences.

  6. Resolution of the Hard Problem: Hoffman's approach offers a different perspective on the hard problem of consciousness. Rather than trying to explain conscious experiences arising from physical processes, he aims to explain physical processes and space-time emerging from conscious experiences.

  7. Variety of Consciousnesses: Hoffman suggests that there is an infinite variety of consciousnesses, and human consciousness is just a small fraction of this diversity. Different consciousnesses might experience reality in entirely unique ways, beyond human comprehension.

  8. Explaining Phenomena: Hoffman acknowledges that his current approach doesn't explain why certain conscious experiences are pleasurable or meaningful, such as why chocolate tastes delicious. He suggests that while his theory has limitations, it provides a framework that allows for these types of questions to be explored in the future.

  9. Non-Fundamental Properties: Hoffman distinguishes his perspective from Max Tegmark's idea of a mathematical multiverse. He asserts that consciousness is more fundamental than mathematics and is responsible for generating mathematical structures and physical realities.

  10. Ongoing Research: Hoffman acknowledges that his theory still has gaps and limitations, but he is working on developing a framework to demonstrate how conscious agent networks could lead to the emergence of space-time, physical objects, and other phenomena.

Overall, the discussion revolves around a paradigm shift in understanding consciousness and the fundamental nature of reality, with conscious experiences as the foundational element.

Conciousness Part II

  1. Consciousness and Formless Reality: The conversation starts with the distinction between consciousness without form and the various forms that consciousness takes for different experiences. The concept of probability space is introduced as a way to represent conscious experiences.

  2. Probability Space and Dynamics: Hoffman uses the analogy of writing down a probability space for conscious experiences, similar to writing down a probability space for the outcomes of flipping a coin. He describes consciousness as a dynamic process where experiences appear and disappear, akin to the appearance and disappearance of outcomes in a probability space.

  3. Interpreting Fundamental Probability Space: The conversation shifts to interpreting the fundamental probability space of consciousness. Hoffman discusses the challenges of understanding the dynamics of consciousness and how experiences arise from this fundamental space.

  4. Mechanism and Hard Problem: The concept of a mechanism for consciousness and the "hard problem" are discussed. Hoffman suggests that if consciousness is fundamental, it might not be about finding a mechanism for it but understanding its inherent nature.

  5. Solving the Hard Problem: Hoffman proposes a solution to the hard problem by considering networks of conscious agents. He suggests that rather than explaining how brains create consciousness, we should explore how networks of conscious agents create what we perceive as brains.

  6. Limitations of Theory: While Hoffman's "conscious agent theory" offers insights, he acknowledges that it might be just a starting point (1.0 theory) and that more complex theories could emerge in the future, like category theory or topoi theory. He also questions whether the ultimate nature of how formless consciousness gives rise to form can ever be fully resolved.

  7. Conversations with Anil Seth: Hoffman mentions discussions with Anil Seth and points out that their ideas about consciousness align quite closely. They talk about consciousness and the self, clarifying that the concept of agency isn't fundamental in Hoffman's theory.

  8. Language and Ambiguity: They discuss the challenges of communicating about consciousness due to the ambiguity of language and the loaded nature of the term. Miscommunication can arise due to the diverse interpretations of consciousness.

  9. Complexity and Evolution: Hoffman introduces the idea that consciousness, even without entropic time, could project itself to form more complex systems and give rise to evolution through projection and interaction. He suggests that the evolution of individual selves and the concept of self could emerge from this projection.

  10. The Search for a Theory of Everything: Hoffman expresses skepticism about the existence of a true theory of everything and suggests that the problem of how the formless gives rise to form might be an unsolvable, primitive question that continuously deepens but never fully resolves.

  11. Challenges to Physicalist Views: The discussion challenges the physicalist view of consciousness, pointing out that despite decades of research, no physicalist theory has provided a specific mechanism or structure that explains conscious experiences.

  12. Stipulating Consciousness: Hoffman proposes that instead of trying to start with physical matter and derive consciousness, it might be more reasonable to stipulate consciousness and explore how the physical world emerges from it.

Overall, the discussion revolves around the deep mysteries of consciousness, the challenges of explaining it within current paradigms, and the potential implications of rethinking the relationship between consciousness and reality.

Visualizing Reality

  1. Visualizing Reality and Limits of Human Perception: The discussion revolves around the limitations of human perception and the quest to visualize reality using tools like mathematics, computers, and the mind. The main question is whether we can overcome these limitations and gain a deeper understanding of reality through visualization.

  2. Incremental Progress in Understanding Reality: The conversation highlights that our understanding of reality has evolved incrementally through history. The development of scientific theories and mathematical equations, such as Faraday's experiments, Maxwell's equations, Planck's quantum theory, and Einstein's relativity, has led to paradigm shifts in our understanding of the physical world.

  3. Challenges of Visualizing Non-Intuitive Concepts: The challenge lies in visualizing concepts that are non-intuitive, such as quantum theory, consciousness, and the nature of reality beyond our ordinary sensory experiences. The conversation explores whether there are ways to bridge this gap and visualize these complex concepts.

  4. Consciousness and Portals: The discussion delves into the relationship between consciousness and physical reality. It introduces the idea of consciousness as a fundamental aspect of reality that creates our perception of the world. The concept of "portals" is used metaphorically to represent the ways through which consciousness interacts with different perspectives and experiences, such as having children and using psychedelics.

  5. Psychedelics and Altered States of Consciousness: The conversation touches on the role of psychedelic substances in altering consciousness and potentially providing glimpses into different dimensions of reality. The idea is that psychedelics might affect the "portals" through which consciousness interfaces with the world, leading to unique experiences.

  6. Theoretical Advances and Paradigm Shifts: The participants express optimism about the potential for theoretical advances in understanding reality. They discuss the excitement of the younger generation of physicists who are exploring concepts beyond space-time, aiming to develop a deeper theory that can explain the origin of the universe, the evolution of space-time, and the emergence of consciousness.

Immanuel Kant

  1. Agreements and Disagreements with Immanuel Kant: The discussion focuses on the ideas of Immanuel Kant, particularly his idealism and his views on the nature of reality. Donald Hoffman acknowledges several points of agreement with Kant's perspective, such as the idea that humans impose structure on nature and that our perception shapes our understanding of reality. However, Hoffman also notes a specific disagreement regarding Kant's assumption of Euclidean space-time being a priori, which he considers false.

  2. Conscious Realism vs. Idealism: Hoffman introduces his own philosophical framework called "conscious realism," which is related to but distinct from idealism. He explains that while his ideas align with some aspects of idealism, he distances himself from the negative connotations associated with anti-science and anti-realism often linked to idealism. He prefers to emphasize the realism inherent in his viewpoint.

  3. Similarities with Other Philosophers: Hoffman mentions similarities between his ideas and those of other philosophers like George Berkeley and Gottfried Wilhelm Leibniz. He points out that Leibniz, in his monadology, recognized the insolubility of the hard problem of consciousness and proposed non-spatial entities called monads. While Hoffman's approach differs, he sees common ground in the attempt to explain consciousness and its relationship to space and time.

  4. Acknowledgment of Humility and Continuation of Ideas: The conversation reflects humility as Hoffman acknowledges that great thinkers like Leibniz would likely have quickly grasped and expanded upon his ideas if they were present today. He suggests that these historical figures would have built upon his framework and taken it further due to their intellectual genius.

Ephemerality of Life

Main Ideas: 1. Ephemerality of Life and Reality: Donald Hoffman discusses the profound implications of his conscious realism theory on the ephemeral nature of life and reality. He explains that, according to his perspective, objects and perceptions only exist when observed and are constantly being created and discarded in a matter of milliseconds. This realization challenges common notions of possessions and identity and aligns with spiritual traditions that emphasize the impermanence of things.

  1. Radical Restructuring of Thought: Conscious realism leads to a radical restructuring of various aspects of human understanding, including possessions, identity, survival after death, and the nature of consciousness itself. Hoffman asserts that consciousness is not confined within the body, but rather the body and its surroundings are created by consciousness as it observes, challenging traditional views of identity and survival.

  2. Mathematical Model of Consciousness: Hoffman's conscious realism offers a mathematical model for consciousness called conscious agents. He notes that the mathematical structures found in physics, such as permutation matrices, coincide with the patterns in his conscious agent dynamics. He aims to link conscious agents to these structures and connect them to the amplitude in physics, ultimately bridging consciousness, physics, and space-time.

  3. Transformation of Perspectives: The discussion highlights how conscious realism shifts perspectives on subjects like possessions, interactions, and identity. Hoffman suggests that understanding the ephemeral nature of reality can potentially lead to a more compassionate and empathetic society, as it challenges the significance of material possessions and the separateness of individuals.

Simulation Theory

  1. Simulation and Partial Rendering: Donald Hoffman discusses the concept of simulation theory, both in terms of Nick Bostrom's idea of living in a simulation and the idea of partial rendering in simulations. He questions the need for a physicalist framework in simulation theories and explores how efficiently a simulation could create convincing interfaces without rendering everything.

  2. Efficiency of Immersion: The discussion revolves around the idea of efficiently creating immersive experiences. Hoffman highlights that virtual reality systems aim to create immersion experiences with minimal rendering requirements. Researchers are studying how to design systems that achieve immersion by tightly linking perception and action and providing expected perceptions.

  3. Engineering Challenge: Hoffman suggests that achieving immersion is more of an engineering problem than a deep scientific challenge. While it involves scientific principles, the focus is on tricking human perceptions and senses effectively without a need for exhaustive rendering.

  4. Shift in Attention and Experience: The conversation explores the nature of human perception by directing attention forward and backward with closed eyes. Hoffman demonstrates how attention influences experience. When attention is directed backward, people often sense an absence of qualia (sensory experiences) but still feel a sense of being.

  5. Unnoticed Absence: Hoffman and Lex Fridman discuss how people often go through life without realizing the absence of qualia behind them. The idea is that humans are so immersed in their experience that they assume there's something behind them even when there isn't.

  6. Childhood Immersion: The concept of immersion is demonstrated by discussing children's reactions in games like peekaboo. Children are easily immersed in the illusion, just as adults are immersed in their perception of reality.

Difficult Ideas

  1. Personal Struggle with Challenging Ideas: The discussion focuses on Donald Hoffman's personal experience and emotional journey with the challenging ideas he has proposed. These ideas deeply impact him on both an intellectual and emotional level, leading to moments of fear, attachment, and introspection.

  2. Attachment to Interface: Hoffman expresses the struggle of reconciling the knowledge that reality is an interface with the deeply ingrained human attachment to physical existence and the material world. He highlights the tension between intellectual understanding and emotional resistance.

  3. Facing Mortality: The conversation delves into the concept of mortality and how facing death, as well as experiencing life-threatening situations, has influenced Hoffman's perspective. The idea of death as a transition from an interface becomes more real and meaningful in light of personal experiences.

  4. Impact on Spirituality and Science: Hoffman discusses how these ideas have led him to explore spiritual traditions more deeply. He acknowledges the value of spiritual insights while still maintaining a scientific perspective. He attempts to integrate scientific understanding with the emotional and experiential aspects of human existence.

  5. Personal Evolution and Transformation: The discussion reveals Hoffman's process of grappling with these ideas, leading to a more profound understanding of himself and his place in the universe. He recognizes the need to bridge the gap between intellectual understanding and emotional acceptance.


Main Ideas: 1. Love and Human Connection: The discussion explores the role of love in the human experience, both in a sexual sense and in a deeper, more profound sense. There's a recognition of love as a fundamental aspect of human connection that goes beyond physical attraction.

  1. Deeper Sense of Love: Hoffman distinguishes between love in the sexual sense and a deeper love that transcends separateness. This deeper love is related to the idea of unity, where individuals are not separate entities but interconnected parts of a larger whole.

  2. Concept of God: The conversation touches on the concept of God as interpreted by various spiritual traditions. Hoffman suggests that God should be understood as the ground of being itself, not as a specific being with distinct attributes. This understanding of God as the essence of consciousness aligns with the idea of interconnectedness.

  3. Unity and Fighting: The discussion highlights how differing concepts of God have often led to conflicts and wars between different religious groups. Hoffman emphasizes that viewing God as the shared ground of being eliminates the need for separation and conflict, as unity becomes the focus.

  4. Intersection of Science and Spirituality: Hoffman notes that his scientific exploration of consciousness aligns with the philosophical and spiritual ideas he discusses. The idea of interconnectedness and a shared ground of being resonates with both scientific and spiritual perspectives.

Advice for Young People

  1. Advice for Young People: Hoffman provides advice to young people, emphasizing that the universe is more fascinating and individuals are more special than they might realize. He encourages them to break away from conventional assumptions, to recognize their potential as creators of reality, and to have an open imagination.

  2. You Are the Creator: Hoffman stresses the idea that individuals are not insignificant in the vastness of the universe. He suggests that every conscious being is essentially the author of space and time, continuously shaping their reality through observation and experience.

  3. Continuous Learning and Innovation: While acknowledging the importance of understanding current knowledge presented in textbooks, Hoffman advises young people to go beyond the existing boundaries. He believes that the limits of progress are only constrained by one's imagination and encourages them to contribute to the creation of new textbooks in the future.

  4. Meaning of Life: The discussion touches on the question of the meaning of life. While this aspect is not elaborated on in the provided text, it suggests that the exploration of consciousness and reality, as discussed earlier, could potentially contribute to a deeper understanding of life's purpose.

Meaning of Life

  1. Exploring the Meaning of Life: The discussion delves into the search for the meaning of life and why consciousness creates complex structures and experiences. Hoffman's hypothesis is that consciousness awakens to itself by knowing what it is not, leading to an evolving understanding of its own nature.

  2. Consciousness and Experience: The conversation explores the question of why consciousness goes beyond mere existence to create complex experiences and forms. The idea is put forth that consciousness immerses itself in experiences and forms, then gradually awakens to escape those forms and limitations.

  3. Waking Up and Knowing What You Are: The idea is presented that consciousness, in order to fully understand itself, needs to both immerse itself in experiences and recognize what it is not. This process of waking up involves realizing that certain experiences and forms are not truly important.

  4. Personal Connection and Appreciation: Lex expresses his admiration and gratitude for Donald Hoffman's insights and contributions, particularly during a difficult time in Hoffman's life. The discussion ends on a note of appreciation for the unique perspectives shared.