# Consciousness (Christof Koch)
* On the one hand is the brain, the most complex object in the known universe, a material thing subject to the laws of physics. On the other hand is the world of awareness, of the sights and sounds of life, of fear and anger, of lust, love, and ennui. (p. 1)
* In philosophy, the difficulty of explaining why somebody can feel anything is often referred to as the Hard Problem. The term was coined by the philosopher David Chalmers. He made his reputation in the early 1990s by a closely argued chain of reasoning, leading him to conclude that conscious experience does not follow from the physical laws that rule the universe. (p. 3)
* The ever-increasing complexity of organisms, evident in the fossil record, is a consequence of the unrelenting competition for survival that propels evolution. (p. 7)
* These two frameworks, one divine and one secular, one for Sunday and one for the rest of the week, did not intersect. The church provided meaning by placing my puny life in the context of the vastness of God’s creation and his Son’s sacrifice for humankind. Science explained facts about the actual universe I found myself in and how it came to be. (p. 12)
* Humanity is not condemned to wander forever in an epistemological fog, knowing only the surface appearance of things but never their true nature. We can see something; and the longer we gaze, the better we comprehend. (p. 12)
* Many scholars consider this gap between the mechanisms of the brain and the consciousness it exudes to be unbridgeable. (p. 26)
* Despite the hectoring of deconstructionist, “critical” scholars and sociologists, science remains humanity’s most reliable, cumulative, and objective method for comprehending reality. It is far from fail-safe; it is beset with plenty of erroneous conclusions, setbacks, frauds, power struggles among its practitioners, and other human foibles. But it is far better than any alternative in its ability to understand, predict, and manipulate reality. Because science is so good at figuring out the world around us, it should also help us to explain the world within us. (p. 27)
* Qualia are the raw feelings, the elements that make up any one conscious experience. (p. 27)
* I believe that qualia are properties of the natural world. They do not have a divine or supernatural origin. Rather, they are the consequences of unknown laws that I would like to uncover. (p. 28)
* Some scholars deny that consciousness has any causal role. They accept the reality of consciousness but argue that subjective feelings have no function—they are froth on the ocean of existence, without consequence to the world. The technical term is epiphenomenal. (p. 31)
* Defining what, exactly, constitutes jazz is notoriously difficult. Hence the saying, “Man, if you gotta ask, you’re never gonna know.” The same holds true for consciousness. (p. 32)
* Consider a related but simpler problem: explaining to a person blind from birth what color is. Defining the percept of red is impossible without referring to other red objects. (p. 32)
* A habitual misperception is that science first rigorously defines the phenomena it studies, then uncovers the principles that govern them. Historically, progress in science is made without precise, axiomatic formulations. (p. 33)
* A commonsense definition equates consciousness with our inner, mental life. Consciousness begins when we wake up in the morning and continues throughout the day until we fall into a dreamless sleep. Consciousness is present when we dream but is exiled during deep sleep, anesthesia, and coma. And it is permanently gone in death. (p. 33)
* A behavioral definition of consciousness is a checklist of actions or behaviors that would certify as conscious any organism that could do one or more of them. (p. 33)
* A neuronal definition of consciousness specifies the minimal physiologic mechanisms required for any one conscious sensation. (p. 34)
* If these three definitions don’t nail the problem, ask a philosopher. She’ll give you a fourth definition, “consciousness is what it is like to feel something.” (p. 34)
* Although consciousness is fully compatible with the laws of physics, it is not feasible to predict or understand consciousness from these laws alone. (p. 35)
* Our brain is big, but other creatures—elephants, dolphins, and whales—have bigger ones. (p. 35)
* Homo sapiens is part of an evolutionary continuum, not a unique organism that dropped, fully sentient, from the sky. (p. 36)
* It is possible that consciousness is common to all multicellular animals. (p. 36)
* The repertoire of conscious states must somehow diminish with the diminishing complexity of an organism’s nervous system. (p. 36)
* Self-consciousness is part and parcel of consciousness. It is a special form of awareness that is not concerned with the external world, but is directed at internal states, reflections about them, and reflections upon such reflections. This recursiveness makes it a peculiarly powerful mode of thinking. (p. 38)
* There is little reason to deny consciousness to animals because they are mute or to premature infants because their brain is not fully developed. (p. 39)
* Emotions are indispensable to a well-balanced and successful life but are not essential for consciousness. (p. 39)
* The question of which brain regions are essential for consciousness is hotly debated. (p. 43)
* Consciousness does not arise from regions but from highly networked neurons within and across regions. (p. 54)
* Clearly, the brain can attend to objects it doesn’t see. (p. 55)
* The two-way dissociations I just discussed, attention without consciousness and consciousness without attention, put paid to the notion that the two are the same. They are not. (p. 57)
* Concept cells demonstrate compellingly that the specificity of conscious experience has a direct counterpart at the cellular level. (p. 66)
* Suppressing knowledge of the certain doom that awaits us all must have been a major factor in the evolution of what Freud calls defense mechanisms (are we the only animals with them? can a chimp suppress or repress?). These are processes by which the brain removes negative feelings, anxiety, guilt, unbidden thoughts, and so on from consciousness. Without such cleansing mechanisms, early humans might have become too transfixed by their ultimate fate to successfully dominate their niche. Perhaps clinical depression amounts to a loss of such defense mechanisms. (p. 76)
* Your interactions are largely governed by forces beyond your ken, by unconscious desires, motivations, and fears. (p. 83)
* Choice blindness is relevant not only to dating but to life in general. You frequently have little idea why you do the things you find yourself doing. Yet the urge to explain is so strong that you make up a story on the spot, justifying your choice, confabulating without realizing it. (p. 87)
* None of the data reviewed here suggests that the unconscious has vast, hitherto untapped powers that can be harnessed to solve your love, family, money, or career problems. Those can only be addressed by thoughtful and disciplined acts and habits cultivated over years, a boring message that few want to hear. (p. 88)
* In a remote corner of the universe, on a small blue planet gravitating around a humdrum sun in the unfashionable, outer districts of the Milky Way, organisms arose from the primordial mud and ooze in an epic struggle for survival that spanned eons. Despite all evidence to the contrary, these bipedal creatures thought of themselves as extraordinarily privileged, as occupying a unique place in a cosmos of a trillion trillion stars. Conceited as they were, they even believed that they, and only they, could escape the iron law of cause and effect that governs everything. They could do this by virtue of something they called free will, which allowed them to do things without any material reason. (p. 91)
* Let me start by offering a definition of free will: You are free if, under identical circumstances, you could have acted otherwise. Identical circumstances refer to not only the same external conditions but also the same brain states. This is the strong, libertarian, or Cartesian position, as it was articulated by Descartes, whom we keep encountering. Will with a capital “W,” the real thing. (p. 92)
* Street gangs inhabit a parallel universe to the privileged and sheltered one in which my family, friends, colleagues, and I live. These worlds, only miles apart, intersect only rarely. (p. 93)
* Yet this Cartesian view of will is the one most regular folks believe in. It is closely linked to the notion of a soul. Hovering above the brain like Nearly Headless Nick, the ghost of Gryffindor House, the soul freely chooses this way or that, making the brain act out its wishes, like the driver who takes a car down this road or that one. (p. 93)
* Compatibilist freedom leaves a residue of unease, a nagging doubt. The absence of overt inner or outer coercion is certainly necessary to be free, but it does not guarantee freedom in the strong sense. If all influences from nature, nurture, and the random factors in your environment are accounted for, is there any room left to maneuver? Aren’t you an utter slave to these constraints? It looks like compatibilism amounts to freedom lite! (p. 95)
* The universe, once set in motion, runs its course inexorably, like a clockwork. To an all-knowing supercomputer, the future is an open book. There is no freedom above and beyond that dictated by the laws of physics. All of your struggles to come to grips with your inner demons, both good and bad, are for naught. The outcome of your future actions was ordained when the universe was wound up at the beginning of time. (p. 96)
* The butterfly effect does not invalidate the natural law of cause and effect, however. It continues to reign supreme. Planetary physicists aren’t quite sure where Pluto will be eons from now, but they are confident that its orbit will always be completely in thrall to gravity. What breaks down in chaos is not the chain of action and reaction, but predictability. The universe is still a gigantic clockwork, even though we can’t be sure where the minute and hour hands will point a week hence. (p. 98)
* According to the inflation theory of cosmology, these superclusters, the largest structures in the cosmos, were caused by stochastic quantum fluctuations that occurred an instant after the Big Bang, which formed the universe. (p. 99)
* Nervous systems, like anything else, obey the laws of quantum mechanics; yet the collective effect of all these molecules frenetically moving about is to smooth out any quantum indeterminacy, an effect called decoherence. Decoherence implies that the molecules of life can be treated using thoroughly classical, deterministic laws rather than quantum mechanical, probabilistic ones. (p. 101)
* Both quantum mechanics and deterministic chaos lead to unpredictable outcomes. (p. 101)
* Yet indeterminism provides no solace for the true libertarian; it is no substitute for free will. (p. 102)
* The only real possibility for libertarian-style free choice is for the mind to realize one quantum mechanical event rather than another, as dictated by Schrödinger’s equation. (p. 104)
* Laypeople and mystics alike have an inordinate fondness for the hypothesis that the weirdness of quantum mechanics must somehow be responsible for consciousness. (p. 104)
* The brain acts before the mind decides! This was a complete reversal of the deeply held intuition of mental causation—the brain and the body act only after the mind has willed it. (p. 106)
* The timing of the muscle movement and the sensation of willing it more or less coincide, but the actual decision to move occurred earlier, before awareness. (p. 106)
* This is a neglected idea in the free will debate—that the mind–body nexus creates a specific, conscious sensation of voluntary movement, a compelling experience of “I willed this,” or “I am the author of this action.” (p. 107)
* The feeling of agency is no more responsible for the actual decision than thunder for the lightning stroke. (p. 107)
* The feeling of agency is generated by a brain module that assigns authorship to voluntary actions based on simple rules. If you planned to snap your fingers and you look down and see them doing that, the agency module concludes that you initiated the action. (p. 109)
* Why you choose the way you do is largely opaque to you. (p. 111)
* I believe that information theory, properly formulated and refined, is capable of such an enormous feat, analyzing the neuronal wiring diagram of any living creature and predicting the form of consciousness that that organism will experience. It can draw up blueprints for the design of conscious artifacts. And, surprisingly, it provides a grandiose view of the evolution of consciousness in the universe. (p. 115)
* This cornucopia of behavior and the numerous structural and molecular similarities between the canine and the human brain lead me to conclude that dogs have phenomenal feelings. (p. 116)
* This cornucopia of behavior and the numerous structural and molecular similarities between the canine and the human brain lead me to conclude that dogs have phenomenal feelings. Any philosophy or theology that denies sentience to them is seriously deficient. (p. 116)
* In this yet-to-be-defined manner, consciousness is not manifest when a handful of neurons are wired together; it emerges out of large networks of cells. The bigger those assemblies, the larger the repertoire of conscious states available to the network. (p. 117)
* Subjectivity is too radically different from anything physical for it to be an emergent phenomenon. (p. 119)
* I believe that consciousness is a fundamental, an elementary, property of living matter. It can’t be derived from anything else; it is a simple substance, in Leibniz’s words. (p. 119)
* Human consciousness is much more rarified than canine consciousness because the human brain has twenty times more neurons than the brain of a dog and is more heavily networked. (p. 120)
* Functionalism applied to consciousness means that any system whose internal structure is functionally equivalent to that of the human brain possesses the same mind. (p. 120)
* Φ denotes the size of the conscious repertoire associated with any network of causally interacting parts. The more integrated and differentiated the system is, the more conscious it is. (p. 128)
* The theory can be used to build a consciousness-meter. This gadget takes the wiring diagram of any system of interacting components, be it wet biological circuits or those etched in silicon, to assesses the size of that system’s conscious repertoire. (p. 131)
* By postulating that consciousness is a fundamental feature of the universe, rather than emerging out of simpler elements, integrated information theory is an elaborate version of panpsychism. (p. 132)
* Teilhard de Chardin believed that the entire cosmos evolves toward what he terms the Omega point, when the universe becomes aware of itself by maximizing its complexity, its synergy. (p. 133)
* Despite the naysayers, science will ultimately understand consciousness by combining empirical and clinical studies with mathematical theories and, increasingly, the engineering of conscious artifacts. (p. 134)
* Eristic philosophical debates are enjoyable and can even be helpful but they don’t resolve the fundamental issues. (p. 137)
* For now, I ignore niggling debates about the exact definition of consciousness, whether it is an epiphenomenon, helpless to influence the world, or whether my gut is conscious but not telling me so. These issues will eventually all need to be addressed, but worrying about them today will only impede progress. (p. 137)
* If I have learned anything in my lifelong exploration of the mind–body nexus, it is this: Whatever consciousness is—however it relates to the brain—dogs, birds, and legions of other species have it. (p. 151)
* It is easy to see causality flowing from the brain to the mind, but the reverse is difficult. Any mind-to-brain communication has to be compatible with natural laws, in particular with the principle of energy conservation. (p. 151)
* If we honestly seek a single, rational, and intellectually consistent view of the cosmos and everything in it, we must abandon the classical view of the immortal soul. It is a view that is deeply embedded in our culture; it suffuses our songs, novels, movies, great buildings, public discourse, and our myths. (p. 152)
* Science has brought us to the end of our childhood. Growing up is unsettling to many people, and unbearable to a few, but we must learn to see the world as it is and not as we want it to be. Once we free ourselves of magical thinking we have a chance of comprehending how we fit into this unfolding universe. (p. 152)
* The dominant intellectual position of our day and age is physicalism—at rock bottom all is reducible to physics. There is no need to appeal to anything but space, time, matter, and energy. Physicalism—a halftone away from materialism—is attractive because of its metaphysical sparseness. It makes no additional assumptions. (p. 152)
* This book makes the argument that physicalism by itself is too impoverished to explain the origin of mind. In the previous chapter, I sketched an alternative account that augments physicalism. It is a form of property dualism: The theory of integrated information postulates that conscious, phenomenal experience is distinct from its underlying physical carrier. (p. 152)
* But without some carrier, some mechanism, integrated information can’t exist. Put succinctly: no matter, never mind. (p. 153)
* I continue to be amazed by the ability of highly educated and intelligent people to fool themselves. You and I are convinced that our motives are noble, that we are smarter than most, that the opposite sex finds us attractive. (p. 158)
* The books of the Bible were written before the true age and extent of the cosmos were even remotely imagined, before the evolutionary bonds between humans and animals were understood, before the brain was identified as the seat of the mind (neither the Old nor the New Testament mentions the brain a single time). (p. 159)
* For many years I, like the vast majority of people, believed what my parents believed. But that is not a truly informed choice. (p. 159)
* One night, my unconscious rebelled. I woke up, and abstract knowledge had turned to gut-wrenching certainty: I was actually going to die! (p. 161)
* What I took from my readings is that I am less free than I feel I am. Myriad events and predispositions influence me. Yet I can’t hide behind biological urges or anonymous social forces. I must act as if “I” am fully responsible, for otherwise all meaning would be leached from this word and from the notions of good and bad actions. (p. 164)
* This is a perhaps overenthusiastic expression of my position on the question of free will: For better or worse, I am the principal actor of my life. (p. 164)
* I am saddened by the loss of my religious belief, like leaving forever the comfort of my childhood home, suffused with a warm glow and fond memories. I still have feelings of awe when entering a high-vaulted cathedral or listening to Bach’s St. Matthew Passion. Nor can I escape the emotional thrall, the splendor and pageantry, of high Mass. But my loss of faith is an inescapable part of growing up, of maturing and seeing the world as it is. (p. 166)