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The Four Realms of Existence: A New Theory of Being Human
One of the world’s leading experts on mind and brain takes us on an expedition that reveals a new view of what makes us who we are.
Humans have long thought of their bodies and minds as separate spheres of existence. The body is physical―the source of aches and pains. But the mind is mental; it perceives, remembers, believes, feels, and imagines. Although modern science has largely eliminated this mind-body dualism, people still tend to imagine their minds as separate from their physical being. Even in research, the notion of the “self” as somehow distinct from the rest of the organism persists.
Joseph LeDoux argues that we have hit an epistemological wall―that ideas like the self are increasingly barriers to discovery and understanding. He offers a new framework of who we are, theorizing four realms of existence―bodily, neural, cognitive, and conscious.
The biological realm makes life possible. Hence, every living thing exists biologically. Animals, uniquely, supplement biological existence with a nervous system. This neural component enables them to control their bodies with speed and precision unseen in other forms of life. Some animals with nervous systems possess a cognitive realm, which allows the creation of internal representations of the world around them. These mental models are used to control a wide range of behaviors. Finally, the conscious realm allows its possessors to have inner experiences of, and thoughts about, the world.
Together, LeDoux shows, these four realms make humans who and what we are. They cooperate continuously and underlie our capacity to live and experience ourselves as beings with a past, present, and future. The result, LeDoux shows, is not a self but an “ensemble of being” that subsumes our entire human existence, both as individuals and as a species.
Humans have long thought of their bodies and minds as separate spheres of existence. The body is physical―the source of aches and pains. But the mind is mental; it perceives, remembers, believes, feels, and imagines. Although modern science has largely eliminated this mind-body dualism, people still tend to imagine their minds as separate from their physical being. Even in research, the notion of the “self” as somehow distinct from the rest of the organism persists.
Joseph LeDoux argues that we have hit an epistemological wall―that ideas like the self are increasingly barriers to discovery and understanding. He offers a new framework of who we are, theorizing four realms of existence―bodily, neural, cognitive, and conscious.
The biological realm makes life possible. Hence, every living thing exists biologically. Animals, uniquely, supplement biological existence with a nervous system. This neural component enables them to control their bodies with speed and precision unseen in other forms of life. Some animals with nervous systems possess a cognitive realm, which allows the creation of internal representations of the world around them. These mental models are used to control a wide range of behaviors. Finally, the conscious realm allows its possessors to have inner experiences of, and thoughts about, the world.
Together, LeDoux shows, these four realms make humans who and what we are. They cooperate continuously and underlie our capacity to live and experience ourselves as beings with a past, present, and future. The result, LeDoux shows, is not a self but an “ensemble of being” that subsumes our entire human existence, both as individuals and as a species.
368 pages, Hardcover
Published October 24, 2023
53 people are currently reading
585 people want to read
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Displaying 1 - 28 of 28 reviews
November 23, 2023
Joseph E. LeDoux’s extremely ambitious (and ultimately successful) effort to answer the RIDICULOUSLY complex questions (a) what is consciousness? (b) how does it arise?
One of my favorite truisms is: for every ridiculously complex question there is a simple explanation that is totally fucking wrong. I don’t think many people will accuse LeDoux of offering an overly simplistic explanation here.
In essence, LeDoux proposes a RIDICULOUSLY (appropriately) complex multi level explanatory framework, whereby consciousness emerges from biological, neurological and cognitive substrates. A more detailed summary is WAY beyond my ability, and way outside the scope of this review.
I actually gave it a shot and then I thought better of it.
The best I can currently offer is a recommendation to read it. And a warning to the would be reader that LeDoux is not a super user friendly writer, and this is not a super fun/casual read. But it is RIDICULOUSLY interesting and rewarding if you’re willing to slog through some rather complicated and dense material.
5/5 stars ⭐️
One of my favorite truisms is: for every ridiculously complex question there is a simple explanation that is totally fucking wrong. I don’t think many people will accuse LeDoux of offering an overly simplistic explanation here.
In essence, LeDoux proposes a RIDICULOUSLY (appropriately) complex multi level explanatory framework, whereby consciousness emerges from biological, neurological and cognitive substrates. A more detailed summary is WAY beyond my ability, and way outside the scope of this review.
I actually gave it a shot and then I thought better of it.
The best I can currently offer is a recommendation to read it. And a warning to the would be reader that LeDoux is not a super user friendly writer, and this is not a super fun/casual read. But it is RIDICULOUSLY interesting and rewarding if you’re willing to slog through some rather complicated and dense material.
5/5 stars ⭐️
April 13, 2024
"The Four Realms of Existence: A New Theory of Being Human" (2023) não passa de um amontoado de ideias do autor, misturadas com ideias de outros autores, sobre as quais LeDoux foi refletindo enquanto estava preso em casa durante a pandemia COVID-19. Falta-lhe uma ideia, uma estrutura capaz de construir e entregar essa nova ideia, falta muita edição e reescrita.
LeDoux limita-se a juntar tudo num novo envelope a que dá o nome de Quatro Reinos da Existência divididos entre Biológico, Neurobiológico, Cognitivo e Consciente. Não se percebe o que são esses reinos, nem porquê estes quarto e não apenas 3, nomeadamente na relação entre o cognitivo e o consciente, mas não só. Mais à frente resolve pegar no modelo sistema dual da cognição, definido por Daniel Kahneman, para o repropor como sistema trial, acrescentando-lhe os reinos Neurobiológico e Consciente ao cognitivo, deixando de fora o biológico!
Mas tudo isto não me chocaria, dado todo o trabalho prévio de LeDoux, o enorme reconhecimento que granjeou ao longo de décadas de investigação. O que me chocou foi ver no meio de toda esta proposta a manutenção da ideia estapafúrdia de que os animais não possuem emoções.
Assumir que tudo aquilo que definimos como emoção nos animais é mera projeção antropomórfica é arredar todo o racional evolucionário da equação. Ou seja, os animais, nomeadamente mamíferos, não são de uma linhagem biológica estranha à nossa, não vieram de outro planeta. Por isso brincam, guerreiam, caminham, correm, bocejam, pensam e planeiam. Dizer que não sentem emoção porque não podem expressar, em palavras, o que sentem é refutar a base da formação da vida na Terra.
https://narrativax.blogspot.com/2024/...
LeDoux limita-se a juntar tudo num novo envelope a que dá o nome de Quatro Reinos da Existência divididos entre Biológico, Neurobiológico, Cognitivo e Consciente. Não se percebe o que são esses reinos, nem porquê estes quarto e não apenas 3, nomeadamente na relação entre o cognitivo e o consciente, mas não só. Mais à frente resolve pegar no modelo sistema dual da cognição, definido por Daniel Kahneman, para o repropor como sistema trial, acrescentando-lhe os reinos Neurobiológico e Consciente ao cognitivo, deixando de fora o biológico!
Mas tudo isto não me chocaria, dado todo o trabalho prévio de LeDoux, o enorme reconhecimento que granjeou ao longo de décadas de investigação. O que me chocou foi ver no meio de toda esta proposta a manutenção da ideia estapafúrdia de que os animais não possuem emoções.
Assumir que tudo aquilo que definimos como emoção nos animais é mera projeção antropomórfica é arredar todo o racional evolucionário da equação. Ou seja, os animais, nomeadamente mamíferos, não são de uma linhagem biológica estranha à nossa, não vieram de outro planeta. Por isso brincam, guerreiam, caminham, correm, bocejam, pensam e planeiam. Dizer que não sentem emoção porque não podem expressar, em palavras, o que sentem é refutar a base da formação da vida na Terra.
https://narrativax.blogspot.com/2024/...
March 28, 2024
This book promised so much, and delivered so little.
Purporting to be a 'new theory of being human', the reader instead is treated to a poorly edited, unsatisfactory, and meandering survey of various existing and past theories, clumsily put together and with no consistency in terms of tone, content, or readership.
It was an exasperating and ultimately fruitless effort to plow through this tome in search of some new insights - all that is said here can be found much more accessibly in various other writers' work.
Joe LeDoux is undoubtedly an academic heavyweight in the field, as evidenced by his stellar career and numerous publications over the years. However, this late effort to synthesize the findings of his decades of pioneering work reads more like a lumpy collection of scattered afterthoughts, optimistically bound together by his phantasmic 'new theory'. Spoiler alert: there is no new theory, except to delineate existing research areas into the scientifically meaningless term of 'realms': Biological; Neurobiological; Cognitive; and Conscious. This supposedly earth-shattering revelation is little more than a taxonomical conjuring trick, one which neither opens up new avenues of research for the scientist nor elucidates the miasma of biology and consciousness for the lay reader.
The prose is dense, tonally deaf, imprecise, and confusing. Some areas receive endless minute detail (lists of brain areas that span pages) without giving any insight, while others are brushed patronizingly aside in a paragraph or two. Homely anecdotes and name-dropping frequently intrude when a thought or argument should be developed instead. A lot of time is wasted high-handedly batting away already debunked earlier scientific theories, such as vitalism, rather than explaining the state of the field at present. There are inconclusive, underdeveloped forays into multiple disciplines: philosophy, evolutionary theory, psychology, and cybernetics all receive a reductionist swatting from LeDoux, without contributing anything to his central claim. He relishes in vanquishing outdated paper tigers and straw men in self-satisfied glee, as if that itself is an academic achievement.
Harvard University Press, shamefully, seem to have hand-waved this frothy, incoherent text through with little or no editing, presumably due to LeDoux's status - multiple typos, grammatical mistakes, and repetitions have made it through to the final hardcover edition.
Ultimately, the book's promise fails to deliver on almost every front. Even if stripped down to a survey of various theories, it would still be poor resource for anyone trying to understand the field - flimsy in many areas, over-technical in others, unbalanced, reductivist, and scattered. I expected far better.
Purporting to be a 'new theory of being human', the reader instead is treated to a poorly edited, unsatisfactory, and meandering survey of various existing and past theories, clumsily put together and with no consistency in terms of tone, content, or readership.
It was an exasperating and ultimately fruitless effort to plow through this tome in search of some new insights - all that is said here can be found much more accessibly in various other writers' work.
Joe LeDoux is undoubtedly an academic heavyweight in the field, as evidenced by his stellar career and numerous publications over the years. However, this late effort to synthesize the findings of his decades of pioneering work reads more like a lumpy collection of scattered afterthoughts, optimistically bound together by his phantasmic 'new theory'. Spoiler alert: there is no new theory, except to delineate existing research areas into the scientifically meaningless term of 'realms': Biological; Neurobiological; Cognitive; and Conscious. This supposedly earth-shattering revelation is little more than a taxonomical conjuring trick, one which neither opens up new avenues of research for the scientist nor elucidates the miasma of biology and consciousness for the lay reader.
The prose is dense, tonally deaf, imprecise, and confusing. Some areas receive endless minute detail (lists of brain areas that span pages) without giving any insight, while others are brushed patronizingly aside in a paragraph or two. Homely anecdotes and name-dropping frequently intrude when a thought or argument should be developed instead. A lot of time is wasted high-handedly batting away already debunked earlier scientific theories, such as vitalism, rather than explaining the state of the field at present. There are inconclusive, underdeveloped forays into multiple disciplines: philosophy, evolutionary theory, psychology, and cybernetics all receive a reductionist swatting from LeDoux, without contributing anything to his central claim. He relishes in vanquishing outdated paper tigers and straw men in self-satisfied glee, as if that itself is an academic achievement.
Harvard University Press, shamefully, seem to have hand-waved this frothy, incoherent text through with little or no editing, presumably due to LeDoux's status - multiple typos, grammatical mistakes, and repetitions have made it through to the final hardcover edition.
Ultimately, the book's promise fails to deliver on almost every front. Even if stripped down to a survey of various theories, it would still be poor resource for anyone trying to understand the field - flimsy in many areas, over-technical in others, unbalanced, reductivist, and scattered. I expected far better.
December 15, 2024
First off, I don't understand why this is not as popular as some of the other consciousness books. Maybe something to do with publishing, or maybe there's beef, I'm not sure. The author comes across as very erudite, he references a lot of research, and is himself a famous neuroscientist, but also seems to have read every pop sci book in the field (some would scoff at references to pop sci, I think I'm fine with it), and personally knows a lot of the key thinkers in neuroscience (at least the vocal ones). He highlights how important working memory is (possibly) to consciousness, and it should be obvious but I never really thought about it before. I did find much of the book hard going, but that might be due to my own deficiency in working memory. A picture is truly worth 1000 words, the diagrams were extremely helpful, and I wish there were more of them, along with occasional summarization. There's a particular diagram in the last few pages that beautifully sums up the LeDoux's theory on consciousness. The author is a proponent of a form of HOT theory, and I actually haven't read about HOT theory before, so reading through that discussion was informative. I do think the book could have been structured differently. Instead of discussing the more lower level biological portions at length, I wish the author just jumped into the consciousness discussion, and went more in depth with it, especially the anoesis part. I disagree with him about there being something special about human biology that would allow consciousness to arise. I think functional reproduction of biology should suffice, but this is definitely something that can be experimented with, so only time will tell. I now have some cognitive dissonance comparing his theory to the one put forth by Solms in the Hidden Spring. They do have differing definitions of consciousness, however. I like that the author reminded me of there being a difference between an animal behaving like it is conscious vs it actually being conscious, there has been a huge movement nowadays to equate the two things, possibly out of moral obligation. His theory on understanding our brain to help understand animal brains is convincing to me, if we can understand the contribution of each brain portion to our consciousness, we might be able to deduce their contribution to animal cognition/consciousness. I do think Ledoux has a lot of very interesting things to say and this is definitely worth a read if you're into this sort of thing.
June 20, 2025
While this book was a fascinating foray into the conversations and research surrounding our understanding of the human mind, the writing itself was clunky and difficult to understand. Those less familiar with the research will find the content interesting but difficult to comprehend. Those familiar with the content will likely not find any cohesion in the presentation of ideas. Additionally, they might be confused as the book is advertised as a “new theory,” but is merely a collection of various theories across the discipline with a lack-luster conclusion of how the study of consciousness should continue. This book is for those that don’t mind sitting and thinking about how the brain works and do not have extensive knowledge of the mind in the first place. Interesting book- difficult read.
September 12, 2024
Joseph LeDoux's book offers a very interesting approach to understanding human existence by integrating cognitive neuroscience with consciousness and biological and evolutionary aspects. Published by Harvard University Press, the book delves into four interconnected realms:
The Biological Realm: This encompasses essential life processes common to all living beings, including metabolism, reproduction, and genetic transfer, highlighting the universality of biological functions.
The Neurobiological Realm: Focusing on the nervous system, this realm explores the regulation of bodily functions and behaviors through neural networks, including rapid processes sometimes under 50 milliseconds.
The Cognitive Realm: Covering mental processes like thinking, learning, memory, and problem-solving, this sphere investigates the internal mechanisms enabling information processing and knowledge formation.
The Conscious Realm: Concentrating on consciousness and subjective experience, this sphere includes awareness of thoughts, feelings, memories, and experiences, and the creation of new conditions through prospective memories.
LeDoux is providing a nuanced understanding of memory, consciousness, and the diversity of the neural predictive system in the different realms, and, of course, the memory updating system and a bunch of neuroanatomical references. He is not afraid of being “naïve” as when he pedagogically repeats basic concepts and basic memory theories, although he immediately puts them into a context of “the four realms” and the "higher order thinking system". He also challenges traditional views in neuroscience, particularly theories such as Paul MacLean's "Triune Brain," emphasising the dynamic evolution and integration of neural networks.
Importantly, LeDoux reflects on different memory systems and provides detailed insights into how different types of memory work, in particular the Tulving and Baddeley systems. In an evolutionary perspective LeDoux integrates Alan Baddeley's working memory model and Endel Tulving's concepts of anoetic, noetic, and autonoetic consciousness, and his episodic, semantic, and procedural memory system, into the Four Realms model. But he also implicitly delves into a catalogue of other memory systems: prospective, preparatory, reflexive, and automatic memory, all of which operate on different timescales. From my point of view these different timescales are most important in a future perspective for the forthcoming exploration of memory research, and for the potential of quantum memories and attosecond research for understanding quantum states in an upcoming new memory theory. LeDoux is not at all explicit about this at all, but I personally think, that these implications offer important speculative hypotheses about how ultra-fast processes at the molecular and atomic level can potentially reshape our understanding of neural processes and memory formation – even of electromagnetic communication between neurons (not synapses).
LeDoux's work is an integrative and important contribution to the fields of neuroscience, psychology, and philosophy. It offers a comprehensive view of human existence, that challenges conventional wisdom and promotes a holistic understanding of the interplay between biology, neurobiology, cognition, and consciousness.
The Biological Realm: This encompasses essential life processes common to all living beings, including metabolism, reproduction, and genetic transfer, highlighting the universality of biological functions.
The Neurobiological Realm: Focusing on the nervous system, this realm explores the regulation of bodily functions and behaviors through neural networks, including rapid processes sometimes under 50 milliseconds.
The Cognitive Realm: Covering mental processes like thinking, learning, memory, and problem-solving, this sphere investigates the internal mechanisms enabling information processing and knowledge formation.
The Conscious Realm: Concentrating on consciousness and subjective experience, this sphere includes awareness of thoughts, feelings, memories, and experiences, and the creation of new conditions through prospective memories.
LeDoux is providing a nuanced understanding of memory, consciousness, and the diversity of the neural predictive system in the different realms, and, of course, the memory updating system and a bunch of neuroanatomical references. He is not afraid of being “naïve” as when he pedagogically repeats basic concepts and basic memory theories, although he immediately puts them into a context of “the four realms” and the "higher order thinking system". He also challenges traditional views in neuroscience, particularly theories such as Paul MacLean's "Triune Brain," emphasising the dynamic evolution and integration of neural networks.
Importantly, LeDoux reflects on different memory systems and provides detailed insights into how different types of memory work, in particular the Tulving and Baddeley systems. In an evolutionary perspective LeDoux integrates Alan Baddeley's working memory model and Endel Tulving's concepts of anoetic, noetic, and autonoetic consciousness, and his episodic, semantic, and procedural memory system, into the Four Realms model. But he also implicitly delves into a catalogue of other memory systems: prospective, preparatory, reflexive, and automatic memory, all of which operate on different timescales. From my point of view these different timescales are most important in a future perspective for the forthcoming exploration of memory research, and for the potential of quantum memories and attosecond research for understanding quantum states in an upcoming new memory theory. LeDoux is not at all explicit about this at all, but I personally think, that these implications offer important speculative hypotheses about how ultra-fast processes at the molecular and atomic level can potentially reshape our understanding of neural processes and memory formation – even of electromagnetic communication between neurons (not synapses).
LeDoux's work is an integrative and important contribution to the fields of neuroscience, psychology, and philosophy. It offers a comprehensive view of human existence, that challenges conventional wisdom and promotes a holistic understanding of the interplay between biology, neurobiology, cognition, and consciousness.
May 12, 2024
Un libro excepcional, merece una releída para poder digerir y procesar toda la info
April 25, 2024
Witty, well written. For once a materialistic theory of consciousness. LeDoux is an expert on neuroscience and on consciousness. He provides a journey through the four major ways neurons process information, in less or more complex ways. Many animals are not cognitive; some are and within them some are conscious. When we get to the neural basis for consciousness, it gets difficult and not so well written. But, it is worth going through.
December 22, 2024
A Reasonable Theory of The Self bogged down in Source Material.
The fundamental theory of the Four Realms comes across very clearly in LeDoux’s book. Unfortunately, for the Lay Reader, he spends an inordinate amount of time laying out the context and history of everyone else’s theory and defending his. This may be necessary and appropriate for a pH.D thesis but less necessary for a Popular Science work.
I was hoping for a greater focus on the Fourth Realm, Consciousness. And LeDoux should have handed off the narration to a Professional. His nasal declamatory style wears thin very quickly. Three Stars. ***
The fundamental theory of the Four Realms comes across very clearly in LeDoux’s book. Unfortunately, for the Lay Reader, he spends an inordinate amount of time laying out the context and history of everyone else’s theory and defending his. This may be necessary and appropriate for a pH.D thesis but less necessary for a Popular Science work.
I was hoping for a greater focus on the Fourth Realm, Consciousness. And LeDoux should have handed off the narration to a Professional. His nasal declamatory style wears thin very quickly. Three Stars. ***
July 11, 2024
In this book, LeDoux presents a summary of his ideas about the self, existence, and consciousness who have merged in a general theoretical framework through his research life (i.e., there is a continuous embedding of biological, neurobiological, cognitive, and conscious existence. This interdisciplinary book encompasses several fields, such as neuroscience, psychology, and even philosophy, proposing a general theory that can be worked from all these fields, which is highly appreciated in contemporary research of the brain/mind. As a bit of a downside, this makes some parts of the book a bit too introductory and overextending in some aspects (e.g., phylogeny evolution). However, because of my interdisciplinary background and my subjective necessity of reviving knowledge of my bachelor, I even enjoyed these overextended aspects. Once LeDoux enters to the PFC-related analysis, the book changes entirely and the reader feels like it is then in LeDoux's home. There is some imbalance between the specificity of PFC explanations and the generality of phylogeny and psychology-related studies. In terms of references and authors, LeDoux does an amazing job doing an extensive review of several authors from different fields that are important for the research of self and consciousness.
In summary, even though the ideas of the book could be better summarized and reduce the length of the book by practically half, I think it has great merit to introduce so many interdisciplinary aspects in one and only book which might be incredibly useful for researchers that want to become interdisciplinary themselves. Totally recommended (4.25/5).
In summary, even though the ideas of the book could be better summarized and reduce the length of the book by practically half, I think it has great merit to introduce so many interdisciplinary aspects in one and only book which might be incredibly useful for researchers that want to become interdisciplinary themselves. Totally recommended (4.25/5).
November 13, 2023
In a recent search for answers, "The Four Realms of Existence: A New Theory of Being Human" by Joseph E LeDoux unexpectedly became a significant milestone. Although it didn't entirely provide all of the answers for understanding, it undeniably acted as a catalyst for introspection, steering me along a path of deep internal contemplation.
LeDoux masterfully writes upon the intricate tapestry of life, skillfully guiding readers through the evolutionary journey that has shaped our existence from primordial beginnings to our current complex state. In this regard, his narrative prowess brought to mind the captivating storytelling found in Yuval Noah Harari's "Sapiens: A Brief History of Humankind"; a book that has secured a place among my favorites.
Whilst I found myself struggling to grasp the intricacies of the later sections, where LeDoux delves into the detailed realms of psychology, this did not diminish my overall enjoyment of the book. LeDoux's ability to distill complex concepts and present them in a comprehensible manner is commendable, even when the subject matter delves into the depths of the human psyche.
LeDoux's skillful storytelling and the book's thought-provoking content make it a worthwhile read for anyone intrigued by the mysteries of human existence, even if some of its psychological depths may require a bit of extra contemplation.
LeDoux masterfully writes upon the intricate tapestry of life, skillfully guiding readers through the evolutionary journey that has shaped our existence from primordial beginnings to our current complex state. In this regard, his narrative prowess brought to mind the captivating storytelling found in Yuval Noah Harari's "Sapiens: A Brief History of Humankind"; a book that has secured a place among my favorites.
Whilst I found myself struggling to grasp the intricacies of the later sections, where LeDoux delves into the detailed realms of psychology, this did not diminish my overall enjoyment of the book. LeDoux's ability to distill complex concepts and present them in a comprehensible manner is commendable, even when the subject matter delves into the depths of the human psyche.
LeDoux's skillful storytelling and the book's thought-provoking content make it a worthwhile read for anyone intrigued by the mysteries of human existence, even if some of its psychological depths may require a bit of extra contemplation.
March 25, 2025
Reading level: third year biology undergrad. It's technical but not too technical.
It's deeper writing than "popular science" but not as deep/dry as a textbook.
Scope: Consciousness + sense of time + comparison of flies/primates/humans + what machine learning taught us + the zones of the brain
My learnings:
1. Organisms all have sensory input entering their nervous system. Organisms tell a story to interpret the input. Mammals tell themselves pretty sophisticated stories. Some birds probably beat some mammals in the depth of meaning-making in their stories.
2. No animal seems to have a sense of "future me".
3. Humans have three me's and part of my personality is what story I tell about prior-me, now-me, future me.
4. I can react to stimulus in two ways:
- habits (low energy cost, saves time, saves calories, saves stress)
- modeling, i.e. actively building the model, extending it on-demand to solve questions (slow, emotional toll, caloric toll)
5. Apes and kids can abstract one level, adult sapiens can go five succesive recursive levels: a prisoner thinking about how she will forever in the future regret the thing she did in the past where she didn't anticipate choice A and choice B about her future.
How to read:
I skipped around, read the chapters randomly, I didn't read any chapter straight through.
It's deeper writing than "popular science" but not as deep/dry as a textbook.
Scope: Consciousness + sense of time + comparison of flies/primates/humans + what machine learning taught us + the zones of the brain
My learnings:
1. Organisms all have sensory input entering their nervous system. Organisms tell a story to interpret the input. Mammals tell themselves pretty sophisticated stories. Some birds probably beat some mammals in the depth of meaning-making in their stories.
2. No animal seems to have a sense of "future me".
3. Humans have three me's and part of my personality is what story I tell about prior-me, now-me, future me.
4. I can react to stimulus in two ways:
- habits (low energy cost, saves time, saves calories, saves stress)
- modeling, i.e. actively building the model, extending it on-demand to solve questions (slow, emotional toll, caloric toll)
5. Apes and kids can abstract one level, adult sapiens can go five succesive recursive levels: a prisoner thinking about how she will forever in the future regret the thing she did in the past where she didn't anticipate choice A and choice B about her future.
How to read:
I skipped around, read the chapters randomly, I didn't read any chapter straight through.
February 11, 2026
Another worthy contribution to the consciousness debates.
The thesis is that consciousness depends on non-conscious processing in the brain.
The author argues that biology is the foundation of neural processes which underlie our cognition that enables our consciousness. Hence, the 4 realms:
1. Biological
2. Neurobiological
3. Cognitive
4. Conscious
All these "make us biological beings with nervous systems that can think, plan, and decide, and that can experience our inner thoughts and feelings."
I like the author's more nuanced approach of breaking Daniel Kahneman's System 1/2 into 3 systems.
Some parts of the book can get a bit dry as it dives into the weeds but overall the ideas presented are very interesting.
The thesis is that consciousness depends on non-conscious processing in the brain.
The author argues that biology is the foundation of neural processes which underlie our cognition that enables our consciousness. Hence, the 4 realms:
1. Biological
2. Neurobiological
3. Cognitive
4. Conscious
All these "make us biological beings with nervous systems that can think, plan, and decide, and that can experience our inner thoughts and feelings."
I like the author's more nuanced approach of breaking Daniel Kahneman's System 1/2 into 3 systems.
Some parts of the book can get a bit dry as it dives into the weeds but overall the ideas presented are very interesting.
September 7, 2024
If you are looking for a book to shed a perspective on the distribution component of consciousness, this book does not contribute an interpretation (at least, as far as I understand).
However-- The Four Realms of Existence provides an otherwise great evolutionary background to the participating factors underlying the conscious (the feeling of living a human life) experience itself. The section on working memory and mental models were great to read and understand their integrations.
The book's pace I really enjoyed, and while I noticed the constant name dropping, it wasn't such a detriment but instead more as a, "if I want to read more about XYZ, this is the person to look up."
However-- The Four Realms of Existence provides an otherwise great evolutionary background to the participating factors underlying the conscious (the feeling of living a human life) experience itself. The section on working memory and mental models were great to read and understand their integrations.
The book's pace I really enjoyed, and while I noticed the constant name dropping, it wasn't such a detriment but instead more as a, "if I want to read more about XYZ, this is the person to look up."
November 14, 2023
LeDoux presents a fascinating theory of consciousness, grounded both in cognitive neuroscience and evolutionary neuroscience.LeDoux presents a framework of four "realms": The Biological Realm, The Neurobiological Realm, The Cognitive Realm, and The Conscious Realm. By meticulously defining and categorizing these "realms", he sheds helps us understand what consciousness is and is not, and how it relates to the many other attributes of life, brains, and intelligence itself.
It is essential reading for anyone interested in the science of consciousness.
It is essential reading for anyone interested in the science of consciousness.
March 21, 2025
Even having no scientific background, you can sniff a survey and a rushed publication held together by a grand idea, which at closer inspection boils down to taxonomy (with ontological aspirations). Still, it was weirdly engaging, as it must be when you listen to an expert in an area, flirting with the reader focusing on known and bashing debunked theories and covering mostly established ideas and not venturing too far afield. It's worth a quick scan, maybe. Otherwise, I'm on a quest to find a book that actually gives it a go and attempts to expose conciseness machinery 😜
January 12, 2024
An outstanding book on research into consciousness along with LeDoux’s Higher Order Theory that postulates how consciousness is created in our brains. With detailed but clear explanations, diagrams, and extensive citing of other researchers’ work, Le Doug skillfully interconnects the contents of each chapter, by asking and answering key questions, and summarizing key details. I came away finally feeling that I understand what makes me feel like someone.
Read
March 14, 2024I can’t rate because I got lost in all the terms and complexity. It’s definitely not for those with a casual interest in his ideas. The last few chapters are a bit easier to understand but he lost me when discussing animals not having consciousness. Also it’s too bad he didn’t read the audible version himself because he has a nice voice. Strongly did not care for the one used and it made it harder to focus in the content.
January 2, 2025
This book was okay in my opinion. I was a little let down by the lack of anecdotes it made the read dry and not as engaging as I hoped. The author definitely has a strong scientific background. Although having the scientific theories to explain potentially what the realms of existence are is important, it also came off as one dimensional and lacked the personal piece of existence.
xx-dnf-skim-reference
March 23, 2025Might be a perfectly good book, but on skim it has too much in common with (and even mentions!) another book I just finished, Being You: A New Science of Consciousness. March 2025
October 4, 2025
Some interesting content and complete overview of the field but in a dificult idiosyncratic presentation format that straddles the broad audience and academic.
I would hope someone else integrates this work and does a clearer job at communicating what he says.
I particularly miss a list of testable hypotheses and of confurmatuons with current experimental results in one place.
I would hope someone else integrates this work and does a clearer job at communicating what he says.
I particularly miss a list of testable hypotheses and of confurmatuons with current experimental results in one place.
August 26, 2025
I enjoyed this book, despite only understanding about a third of it. If, like me, you have ever wondered how the "I" inside your head came to be "you," this is a book for you. I'm starting it all over again.
December 9, 2023
"Biology is no longer considered the sole basis for sexual identity."
January 18, 2024
I didn't actually finish this one. I couldn't. I didn't like his book the deep history of ourselves so I don't know why I started this one anyway.
May 15, 2024
Amazing book with a premise that's straight forward and understandable.
Read
March 16, 2025Either the present is an illusion or it’s the only thing that’s real
December 29, 2023
RK AUDIBLE DMPL AN ORGANIZED DEFENSE OF REPRESENTATIONAL THEORIES OF MIND. REVIEW REALMS AND BIBLIOGRAPHY IF I USE.
August 12, 2024
Having reread the last chapters several times, which were the most challenging bits of my first reading, I finally feel like having some things to write about this book without, I hope, being easily convicted of being either too enthusiastic or too reserved.
A very long review is in progress.
As a standin:
While LeDoux has been criticized in multiple reviews of being a bit unsure about his audience, I find this book to be immensely educative, even if perhaps didactically not perfectly construed.
LeDoux is clear sighted and one of the world's authorities when it comes to several specific brain circuits, and has established himself over the recent years more and more as someone on the frontiers of emotion and consciousness research.
So he is perfectly placed to give a state of the art overview LeDoux edition.
Further his interest in evolutionary neurobiology allows him to build up the organization step by step from 'simple' organizisms to us humans, adding layers of complexity with the eons.
Principly I believe this how a book of this kind ought to be organized for maximum expressivity and comprehensibility.
His Multi level hierarchical higher order theory of consciousness is nuanced, and while not outright solving the qualia problems, is the finest attempt at pulling consciousness into parts that I have read about. The major quality of it is that it is thoroughly anatomically orientated and gives of the impression of "whatever consciousness is, it works with the anatomical structures LeDoux mentioned very likely in the way LeDoux indicates".
Still, it is a novel theory, and not yet completely fleshed out in every detail, and not in this book anyway.
My biggest criticism is LeDouxs tendency of being too concise. Things are explained in one to five sentences and then just assumed as understood. A decent amount of examples or more piecemeal breakups and repetitions would have made the book around 100 pages longer perhaps, but might have hammered home many points more easily.
The way it has been done, to understand the arguments as a non expert not intimately familiar with the specific terminology of schema, mental models and the like, one has to do exegesis exercises to find the few sentences where LeDoux mentioned precisely what he meant, and sometimes, admittedly this is still not really much to go on.
Maybe this is LeDoux resourcefulness, or simply constraints given by the publisher, but maybe this is also due to the schematic nature of much of the theorizing in the book. Some concepts are relatively vague, in order to be more inclusive I believe, and many relationships aren't yet decisevely understood, and good scientist that LeDoux undoubtedly is, he writes rather less that is nonetheless certain than more that is not.
To boot, here comes my last trouble. While he links many papers he used as additional resources, and sorts them by chapters, a real academic citation as it would have been done in a paper seemed fitting to me, and would have made it easier to use the book for academic purposes. Now to build up on the book, it's a bit of puzzle work, and given the sparse definition of his terms, a direct linkage to the papers where the terms were used in exactly the way he means to use them would have been great, especially since I sense that he could have done it from memory at many parts, freely as he is paraphrasing researchers, papers and their findings.
So, there are formal issues, actually hindering the mainstream appeal, or bluntly, the appeal of this book to a degree, but since the content is so great, and LeDoux is no mean writer, tho digging in is needed, my recommendation is as follows:
If you are interested in the brain, this is a challenging book, but probably a rewarding one.
To get the most use out of the book, I would say you gotta make a good amount of effort
What for? You might find yourself having a cogent model of analyzing the psychology of yourself and others on a general level, as well as a one go ressource for interesting knowledge regarding learning psychology.
As goes the usefulness of his consciousness, and cognition account:
I will try to think more in the way of different abstraction levels of mental models now, but how useful and integrable into every day life it is, I can't say yet. Seeing that I believe it to be true, I think it might proove to be intuitive in some situations tho.
A very long review is in progress.
As a standin:
While LeDoux has been criticized in multiple reviews of being a bit unsure about his audience, I find this book to be immensely educative, even if perhaps didactically not perfectly construed.
LeDoux is clear sighted and one of the world's authorities when it comes to several specific brain circuits, and has established himself over the recent years more and more as someone on the frontiers of emotion and consciousness research.
So he is perfectly placed to give a state of the art overview LeDoux edition.
Further his interest in evolutionary neurobiology allows him to build up the organization step by step from 'simple' organizisms to us humans, adding layers of complexity with the eons.
Principly I believe this how a book of this kind ought to be organized for maximum expressivity and comprehensibility.
His Multi level hierarchical higher order theory of consciousness is nuanced, and while not outright solving the qualia problems, is the finest attempt at pulling consciousness into parts that I have read about. The major quality of it is that it is thoroughly anatomically orientated and gives of the impression of "whatever consciousness is, it works with the anatomical structures LeDoux mentioned very likely in the way LeDoux indicates".
Still, it is a novel theory, and not yet completely fleshed out in every detail, and not in this book anyway.
My biggest criticism is LeDouxs tendency of being too concise. Things are explained in one to five sentences and then just assumed as understood. A decent amount of examples or more piecemeal breakups and repetitions would have made the book around 100 pages longer perhaps, but might have hammered home many points more easily.
The way it has been done, to understand the arguments as a non expert not intimately familiar with the specific terminology of schema, mental models and the like, one has to do exegesis exercises to find the few sentences where LeDoux mentioned precisely what he meant, and sometimes, admittedly this is still not really much to go on.
Maybe this is LeDoux resourcefulness, or simply constraints given by the publisher, but maybe this is also due to the schematic nature of much of the theorizing in the book. Some concepts are relatively vague, in order to be more inclusive I believe, and many relationships aren't yet decisevely understood, and good scientist that LeDoux undoubtedly is, he writes rather less that is nonetheless certain than more that is not.
To boot, here comes my last trouble. While he links many papers he used as additional resources, and sorts them by chapters, a real academic citation as it would have been done in a paper seemed fitting to me, and would have made it easier to use the book for academic purposes. Now to build up on the book, it's a bit of puzzle work, and given the sparse definition of his terms, a direct linkage to the papers where the terms were used in exactly the way he means to use them would have been great, especially since I sense that he could have done it from memory at many parts, freely as he is paraphrasing researchers, papers and their findings.
So, there are formal issues, actually hindering the mainstream appeal, or bluntly, the appeal of this book to a degree, but since the content is so great, and LeDoux is no mean writer, tho digging in is needed, my recommendation is as follows:
If you are interested in the brain, this is a challenging book, but probably a rewarding one.
To get the most use out of the book, I would say you gotta make a good amount of effort
What for? You might find yourself having a cogent model of analyzing the psychology of yourself and others on a general level, as well as a one go ressource for interesting knowledge regarding learning psychology.
As goes the usefulness of his consciousness, and cognition account:
I will try to think more in the way of different abstraction levels of mental models now, but how useful and integrable into every day life it is, I can't say yet. Seeing that I believe it to be true, I think it might proove to be intuitive in some situations tho.
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