On Intelligence” fulfills Jeff Hawkins‘ dream to encapsulate a basic theory of intelligence in a straightforward plainly written book. Written with science writer Sandra Blakeslee, “On Intelligence” combines Mr Hawkins’ motivational autobiography, a review of natural and artificial intelligence, and a philosophical discussion delivered in a no-nonsense, unembellished, yet stimulating narrative.

At its core, “On Intelligence” postulates that all higher cognitive functions are built on a single relatively simple algorithm replicated across the neocortex. This hypothetic “basic cortical algorithm” is described as a predictive autoassociative hierarchical network. Left to its own devices, such a neural network should spontaneously generate stable invariant representations of regularities in the environment giving birth to perception, behavior, thoughts, consciousness, and imagination. If we could only mimic Nature and build such a network in silicon, we should be able to make computers that learn, think, and imagine. Mr Hawkins admits that most of these ideas are not original and his contribution is to organize them into a coherent hypothetical framework.

How credible is Mr Hawkins’ hypothesis? How do we know the brain does this? How do we know that such an artificial model would exhibit animal-like intelligence? Mr Hawkins’ answer is: be optimistic — we are way overdue for some kind of a general theory of the brain. In a break from scientific form, Mr Hawkins does not seek out contradictory evidence. The autobiographical sections carry an air of a quixotic struggle against the errors and prejudices of the scientific and corporate establishments of the past and present, who lack the audacity to imagine that a comprehensive theory of intelligence could be within reach. In its more technical sections, the book identifies specific cortical structures responsible for these computations in rather computational than biological terms. No experimental evidence and no working computer models are described or reviewed critically. Instead, the key premises derive from introspection and personal interviews with authorities on the subject, e.g. “I had spoken to several … experts and asked them to explain…” Mr Hawkins mixes experimentally supported findings with speculation and swiftly decides standing controversies without identifying them as such, leaving a casual reader with an exaggerated impression of how much is understood about cognition. In this way, the book often reads rather like marketing material for a specific approach than a thoroughly researched thesis presenting latest scientific findings.

Every neuroscientist strives to intuit a fundamental principle behind the ocean of facts about the nervous system and every computer scientists dreams of creating systems that could develop intelligence. Yet Nature is slow to give up its recipes. By helping envision what the answers could be, “On Intelligence” stands to inspire the budding scientist and engineer with the confidence to probe into the most daunting natural phenomenon that is intelligence. And it is for its enthusiasm and inspiration that “On Intelligence” earns my four stars.


Francis Crick was being coy when he titled his book “The astonishing hypothesis”: that all cognitive processes, including consciousness, are the product of neurons is much more than a hypothesis — it is a mature theory and a subject of active multidisciplinary investigation. The popularization of this insight may meet similar resistance as Darwin’s theory (although it may simply be lumped together with ‘Darwinism’). The view of consciousness as interaction of several mechanisms (or as Dan Dennett calls it, “a bag of tricks”) disagrees with the common sense notion of self as indivisible whole, the starting point in philosophical search (Cogito ergo sum). Therefore, all interesting philosophy of the next decades will be informed by recent experimental findings in neuroscience. Many authors are attempting to popularize the notions of neuronal nature of self. Others are taking advantage of the confusion to push a pet speculation or dogma.

Below I have compiled this chart with several books I have read that address questions of consciousness in intriguing ways. I rated these books based on how much new knowledge or insight they seemed to provide and whether these insights came by way of empirical findings or unfounded speculation. Click to enlarge.

Luckily, many popularizers of scientific understanding of mind and consciousness have made public presentations that are now available online. These make good previews of the contents of their books, and, if you have a couple of hours, getting to know these people will be time well spent.

Daniel Dennett:

Lectures on consciousness:

Jeff Hawkins, “On intelligence”

Christof Koch, “The Quest for Consciousness”

“How Round Is Your Circle” by John Bryant and Chris Sanguin has been delighting my mathematical senses for two nights straight with a collection of counterintuitive, paradoxical, and insightful geometrical toys. Try this: What three-dimensional shape has the same width in all directions (other than a sphere)? My most mathematically-minded friends could not believe that such a thing could exist. Turns out there are many of them.

The authors have created a website illustrating some of the objects from the book, but the book has many more.

There seems to be a category of problems that most people get wrong when they first hear or see them. It takes a second deeper look to get the right answer. Here are a few examples that come to mind:

  1. When the Space Shuttle transfers from a higher orbit into a lower orbit, it fires its engines in reverse to slow down twice on opposite sides of the planet. Will the shuttle be moving faster or slower at the end of the maneuver? (faster)
  2. During descent, commercial airplanes often raise spoilers on top of their wings to increase drag and reduce lift so that they can steepen their approach. Will the airplane slow down or speed up as the result? (speed up)
  3. As the ice melts in Antarctica and Greenland, ocean levels rise across the globe. Will the average ocean depth increase or decrease as the ocean levels rise? (probably decrease)

To illustrate this last problem, can you imagine a bowl that has the following wonderful property: as you add more soup to it, the average depth of the soup in the bowl stays constant? Magic? Not really? I have just whipped up just such a bowl in Matlab:

Once you fill the initial cylindrical portion with water, adding more water will leave the average water depth in the bowl the same: h0. The Great Salt Lake probably has this property: as it gets more water, it gets shallower (on average).

Imagine an extraterrestrial biologist Ph.D. candidate who receives regular samples of Earth’s species. In each shipment, she receives a single living ant. She studies it carefully and thinks she understands it completely: every molecular pathway, every gene, metabolism, and behavior. She dissects the next and receives the next shipment. After several years, she submits her research to her committee and prepares for her career as a myrmecologist. She puzzles over how such a simple creature with only 100,000 neurons, nearly blind, can survive in a world of any complexity. During her doomed defense, her shrewd committee chair asks her, “Have you tried putting a thousand ants together, or a billion?” “Why should I? I know every possible thing about every possible kind of ant on Earth.” “You may learn something new.” Boiling with resentment, she concedes and, after two more arduous years (equalling quite possibly several millennia on Earth) of research and many more ant abductions, she writes a new dissertation titled “Anthills: the organisms we almost missed.”

Emergence describes a common phenomenon taking place at many levels in nature: when simple objects interact in large numbers, they produce new behaviors that defy straightforward inference from the properties of the simple objects. Hegel described emergence in his dialectics as the Law of Transformation: quantitative developments lead to qualitative changes. John Stuart Mill in his System of Logic described the limitations of logic when pressed against emergent processes: one cannot use logic to predict what will happen if many components interact at a larger scale.

Although I don’t claim substantial expertise on epistemology, consilience or unity of all knowledge has always appealed to me. I have never empathized with physicists who disparage biology as a “soft science” that cannot reveal any real laws of nature or biologists who think of anthropology, economics, or sociology as mere philosophy or poetic musings. As for philosophy and poetic musings, I also find a place in the unified fabric of knowledge.

Emergence separates and unites sciences. For a physicist, the entire universe comprises nothing but innumerable elementary particles interacting ceaselessly. Her perfect knowledge of these particles does not mean that she knows anything of chemistry. The laws of chemistry arise as the result of emergence. Biology, in turn, describes the laws of life, which emerge from chemistry. Psychology and cognitive sciences describe laws that emerge from biology. Sociology, economics, political science, and macrohistory again capture regularities that do not directly derive from cognitive sciences, separated from them by emergence.

Separated by emergence, natural phenomena and scientific disciplines may appear convincingly unrelated. Most of us cannot comprehend life as emergence from inorganic chemistry. Most do not accept consciousness as emergence from living cells. Most have a hard time conceiving of society emergence from individual behaviors, preferring to believe in governed or conspiratorial mechanisms. Emergentism seems too difficult for most of us to accept.

“Consilience” by Edward Wilson argues convincingly for unity of natural sciences, social sciences, arts, and philosophy with numerous supporting examples. As a biologist, Wilson views the world from an uncommon intellectual vantage point. Biologists routinely relate their subject back to chemistry and physics and forward to psychology and anthropology. To them, the unity of knowledge becomes experiential.

For a long time, chemists have proudly professed their discipline as the unifying science bringing together biology and physics. As the scientific method proliferates into social sciences, will neuroscience increasingly contribute to the unification of knowledge by joining “sciences of the soul” with biology?

Anthropologist Ernest Becker dedicated his life to validating a simple hypothesis: awareness of one’s death collectively drives a vast majority of social phenomena across all humans societies.

Becker’s lifelong project, the 1974 treatise “The Denial of Death” presented incredibly thorough evidence (psychiatric, sociological, anthropological, and historical) that, in order to function, humans must either deny death or adopt a system of cosmic heroism.

Becker starts from a simple syllogism:

  1. As any higher animal, man possesses powerful innate instincts to preserve his own life
  2. Unlike any other animal, man comes to realize inevitability of his own death
  3. 1 and 2 combine to produce debilitating persistent uniquely human angst that he seeks to relieve

Humans go to great lengths to deny their mortality. In most societies, physiological functions such as excretion and sex have become shameful because they equate us with mortal animals and finite unstable physical matter. I particularly enjoyed the citation of a tribe whose members did not publicly recognize the practice of defecation. They used anal plugs at all times and defecated only in secret. [TODO: look up tribe]. Man must explain his biologically motivated actions in terms of more significant cosmic events to deny death. Romantic love, for example, helps us conceive of sex and procreation as a cosmic force beyond ourselves.

Becker goes on to explain that more than our finiteness, we fear our insignificance. Therefore, humans have developed systems of heroism (Becker’s term for significance). Such a system of significance must provide two essential elements:

  1. a structure or endeavor that provides a sense perpetuity and/or cosmic significance
  2. a role for the person in which she can apply herself within that system

People may construct such systems deliberately or such systems may emerge and evolve spontaneously over time fueled by common anxieties.

Becker’s well illustrated examples of such systems included pursuit of wealth and consumerism, patriotism, Nazism, Communism, religions, science, art, and political power, among others. Anything that threatens our system of significance we call evil. Cues and emblems associated with our systems of cosmic significance give us a rush of euphoria and we will defend them to the death of others, ourselves, and our loved ones.

A person who does not adopt such a system commonly experiences social death — loss of meaning, feeling, and motivation, or aggression to make oneself meaningful at any cost (e.g. mass shootings).

War and genocide owe their existence to conflicting systems of significance.

A person’s system of significance may become more valuable to him or her than their own life or the lives of countless others. An attempt to deconstruct such a system by argument and reason, no matter how substantial, will meet the most vehement resistance.

Many crusaders for reason such as Sam Harris and Richard Dawkins attempt to convince people by evidence and reason of the deceptions in their faiths in mythological gods. Yet they seem oblivious to the life-sustaining role that these systems play for their adherents. Educators would better serve the public by building up systems of significance that fulfill their two roles while leaving behind violent irrational systems of significance.

To my greatest delight, I recently discovered a documentary (wikipedia) based on Becker’s work. The following preview provides a glimpse:

“Flight from death” succinctly captures the essence of Becker’s work although without the hundreds of examples and references in his books. Even after reading several of Becker’s books (“The Denial of Death”, “Escape from evil”, “The birth and death of meaning”), the movie still made an unexpectedly resonant impression on me.

Both the book and the movie get somewhat dire in the middle. If you realize that constructs that give you a sense of belonging and purpose, do so only to help you subconsciously overcome your sense of insignificance, how should one exist? But the book and the movie both provide an optimistic outlook. Accepting one’s physical nature, vulnerable body, physiology, sexuality, mortality, and finiteness, free from systems of significance that lie and kill, one can find or make more transcendent, genuine, universal, and cognizant life.

Somewhat metaphorically, Ernest Becker died at age 49 just before the publication of “The Denial of Death.” Sam Keen recounts with great emotion and compassion his last interview with the dying philosopher:

Becker’s writings inevitably lead to introspection. Which model do you follow? Do you simply deny death and your insignificance? Or have you adopted or created a system of cosmic significance for yourself? How did you choose your system? How does it motivate you? Does it ever fail to give you meaning?

When two systems interact, they often produce feedback loops.

A feedback loop arises when some property of the first system governs some property of the second system while, at the same time, the second property governs the first property, with some delay. Expressed as numeric values, we can plot these properties as functions of time and even describe them in the form of a differential equation and predict outcomes.

Now imagine that the two systems in question represent two persons in a relationship and the two variables regulating one another represent their emotional states. If we could measure the degree of influence of one partner’s emotions on those of the other, we could express the dynamics of their relationship as a differential equation. If we do so with sufficient accuracy, the differential equation could then predict the couple’s mood and attitude fluctuations toward one another.

Mathematics of marriage: dynamic nonlinear models provides the tools for analysis and prediction of the behavior of such nonlinear dynamic systems.

How can these formulas predict divorce or a similar breakdown of a human relationship?

Catastrophic instability arises from unchecked positive feedback. Despite its rather upbeat name, positive feedback usually spells trouble: it arises when a change in the value of a variable causes further proportional change in the same direction. For example, A experiences anger, which causes B to experience more anger, which causes A to experience more anger yet, and so forth until the system disintegrates. Nuclear fission serves as another example of positive feedback leading to catastrophic meltdowns or explosions.

What does nonlinear mean? In a nonlinear system, a change of the value of a variable will produce different effects depending on the current state of the dependent variable. For example, person B in a good mood might not experience the same jolt of anger in response to A’s angry diatribe as she would when in a neutral mood.

Nonlinear dynamics require more sophisticated mathematical tools than linear systems. Still, they only approximate the full dynamics of a relationship which must have a myriad of nonlinearly dependent variables.

Stranger yet, these variables seem to lie outside of our conscious control or even awareness. In “A General Theory of Love” the authors (three practicing psychotherapists) lay out their understanding of love as stable mutual regulation of limbic systems of mammals. The limbic system of the mammalian brain governs the animal’s emotional states, affect, and motivation. Through mostly nonconscious expressions of emotion, limbic systems of two mammals influence one another. Thus, mammals can often communicate across species thanks to their similar wiring: polar bears play with huskies and your dog understands perfectly how you feel at the end of the day and his elation shines through to your perception at the smallest hint of affection or playfulness.

The authors define love as “finding someone who regulates you well and staying with them.”

These musings don’t qualify as science yet, but they hint at a direction. We can make many falsifiable hypotheses and design specific experiments to test them.