From Bacteria to Bach and Back: The Evolution of Minds

by Daniel C. Dennett

Evolutionary processes brought purposes and reasons into existence the same way they brought color vision (and hence colors) into existence: gradually.

The word “reason” is acceptable in all four questions (at least to my ear—how about yours?), but the answers to (1) and (3) don’t give reasons (there aren’t any reasons); they give causes, or process narratives.

plants don’t have understanding; they’re living robots.

Interestingly, when there isn’t enough stability over time in the selective environment to permit natural selection to “predict” the future accurately (when “selecting” the best designs for the next generation), natural selection does better by leaving the next generation’s design partially unfixed, like a laptop that can be configured in many different ways, depending on the purchaser’s preferences and habits.

costly signaling theory (Zahavi 1975; Fitzgibbon and Fanshawe 1988).

The rule of attribution must be then, if the competence observed can be explained without appeal to comprehension, don’t indulge in extravagant anthropomorphism.

she flies away at the opportune moment, once the predator is some distance from her nest.

Such an experience of an abrupt onset of understanding can easily be misinterpreted as a demonstration that understanding is a kind of experience (as if suddenly learning you were allergic to peanuts would show that allergies are a kind of feeling), and it has led some thinkers to insist that there can be no genuine comprehension without consciousness (Searle [1992] is the most influential).

But the distinction between comprehension and incomprehension is still important, and we can salvage it by the well-tested Darwinian perspective of gradualism: comprehension comes in degrees.

progeny. This is “operant conditioning” and B. F. Skinner, the arch-behaviorist, noted its echo of Darwinian evolution, with the generation and testing occurring in the individual during its lifetime but requiring no more comprehension (mentalism-fie!) than natural selection itself. The capacity to improve one’s design by operant conditioning is clearly a fitness-enhancing trait under many circumstances,

letting “their hypotheses die in their stead” as the philosopher of science Karl Popper once put

The “habit” of “creating forward models” of the world and using them to make decisions and modulate behavior is a fine habit to have, whether or not you understand it.

It is this that ties together economic information in our everyday human lives with biological information and unites them under the umbrella of semantic information.

Semantic information is not always valuable to one who carries it. Not only can a person be burdened with useless facts, but often particular items of information are an emotional burden as well—not that evolution cares about your emotional burdens, so long as you make more offspring than the competition.

getting a benefit without going to the cost of manufacturing poison, and when the mimics outnumber the genuinely poisonous snakes Aesop’s moral takes hold and the deceitful signal loses its potency.

1.Semantic information is valuable—misinformation and disinformation are either pathologies or parasitic perversions of the default cases. 2.The value of semantic information is receiver-relative and not measurable in any nonarbitrary way but can be confirmed by empirical testing. 3.The amount of semantic information carried or contained in any delimited episode or item is also not usefully measurable in units but roughly comparable in local circumstances. 4.Semantic information need not be encoded to be transmitted or saved.

People are often designers, and designing takes time and energy (and a modicum of intelligence unless you are an utter trial-and-error plodder, an R&D method which almost never bears interesting fruit except over evolutionary time).

one of Darwin’s most important contributions to thought was his denial of essentialism,

thing. Darwin showed that different species are historically connected by a chain of variations that differed

In the case of Picasso, a barefaced lie. He often made hundreds of sketches with variations on a theme, nibbling away in Design Space until he found something he thought was a good stopping point for his journey.

as Herbert Simon pointed out many years ago, in his brilliant little book The Sciences of the Artificial (1969), complex evolvable systems (basically all living, evolvable systems) depend on being organized “hierarchically”:

theory into the wrong regions of Design Space for half a century and more. Shannon’s enabling stroke was to abstract the concept of information away from thermodynamics, away from the concept of energy

CAn the information for designing software be modeled as such?

Bayesian statistics, then, is a normative discipline, purportedly prescribing the right way to think about probabilities.41 So it is a good candidate for a competence model of the brain: it works as an expectation-generating organ, creating new affordances on the fly.

speculative model of dreams and hallucinations based on analysis by synthesis, arguing that the elaboration of content in these phenomena could be due to nothing more than a “disordered or random or arbitrary round of confirmation and disconfirmation” (p. 12). This has been spectacularly supported and refined by recent work at Google Research (e.g., Mordvintsev, Olah, and Tyka 2015). Today I could simplify my account: in a Bayesian network silence counts as confirmation. Whatever the higher levels guess counts as reality by default in the absence of disconfirmation.

But reasons are things for us. They are the very tools and objects of top-down intelligent design. Where do they come from? How do they get installed in our brains? They come, I am now at last ready to argue in some detail, via cultural evolution, a whole new process of R&D—less than a million years old—that designs, disseminates, and installs thinking tools by the thousands in our brains (and only our brains), turning them into minds—not “minds” or sorta minds but proper minds.

silencing genes while leaving them unchanged is a likely path to the desired results. Then, when descendants of the domesticated animals escape and go feral, all that has to happen, genetically, to restore the wild characteristics that have been suppressed is the removal of the “brackets” that enclose the legacy code, which then springs back into action. This may well explain the strikingly quick reversion to wild traits that occurs in feral lineages.

This strange idea of mindless informational things that provoke coalitions of rebellious neurons to support them, the idea of memes infecting brains, will take several chapters to articulate and defend.44 Here I am pointing out that if anything like that invasion happened, it would no doubt involve a coevolutionary process in which human brains—the only brains so far seriously infected with memes—were selected for handling memes, sheltering them and aiding in their reproduction, in much the way fig trees have coevolved with the parasitic wasps who return the favor by helping pollinate the fig trees.

One of the facts of life, both genetic and cultural, is that options become obligatory. A clever new trick that gives its users a distinct advantage over their peers soon “spreads to fixation,” at which point those who don’t acquire it are doomed.

We are also gradually acquiring theoretical understanding, and genuine comprehension, of the reasons for the features of our communication systems. Those who excel at this research often sell their services as intelligent designers of communication—public speaking coaches, marketing consultants, advertisers—but as we can confirm in other areas of human endeavor—jazz comes particularly to mind—theory is often no match for ear, even when it is good theory.

Turing’s invention of the digital computer can serve as our parade case of top-down intelligent design, and from what we can glean from the records of those heroic years, his path was no beeline to glory, but a meandering exploration of possibilities, sidetracks, false starts, adjusted goals—and plenty of serendipitous help from encounters with other thinkers thinking about other problems.

can’t just download my app to your brain and let it run; control must be accomplished by negotiation, diplomacy, and even, on occasion, pleas, threats, or other emotional nudges. In general I have to secure your attention, your cooperation, even—to some degree—your trust, because you are and ought to be vigilant against possible manipulation by other agents.

Since there is no such thing as “real magic,” whatever trajectory a genius mind manages to pursue must ultimately be accounted for in the cascade of cranes that have been designed and erected over the last few billion years. One way or another, the mind was lifted (by good design) into a region of Design Space from which its further forays were admirably swift and effective.

the discredited mantra from the 1960s: boys and girls are “biologically” the same; all differences are due to socialization and other cultural pressures. That is politically correct nonsense. Male and female brains are not exactly alike. How could they be, given the differences in paternal and maternal biological roles? There are dozens of reliably detectable differences of neuroanatomy, hormonal balance, and other physiological signs, and their genetic sources are not in doubt. Moreover, these physical differences issue in differences in cognitive and emotional competence and style that are statistically significant (see, e.g., Baron-Cohen 2003). But there is plenty of variation between women, and between men, so some women excel at tasks that mostly men excel at, and vice versa. Besides, we’re asking what

Since there can be competence without comprehension, and since comprehension (“real” comprehension) is expensive, Nature makes heavy use of the Need to Know principle, and designs highly successful, adept, even cunning creatures who have no idea what they are doing or why.

defeats. It used to be obvious that the sun circled the earth, after all.

by the ethologist and roboticist David McFarland (1989), “Communication is the only behavior that requires an organism to self-monitor its own control system.”

Communication, McFarland claims, is the behavioral innovation which changes all that. Communication requires a central clearing house of sorts in order to buffer the organism from revealing too much about its current state to competitive organisms. As Dawkins and Krebs (1978) showed, in order to understand the evolution of communication we need to see it as grounded in manipulation rather than as purely cooperative behavior. An organism that has no poker face, that “communicates state” directly to all hearers, is a sitting duck, and will soon be extinct (von Neumann and Morgenstern 1944). What must evolve to prevent this exposure is a private, proprietary communication-control buffer that creates opportunities for guided deception—and, coincidentally, opportunities for self-deception (Trivers 1985)—by creating, for the first time in the evolution of nervous systems, explicit and more globally accessible representations of its current state, representations that are detachable from the tasks they represent, so that deceptive behaviors can be formulated and controlled without interfering with the control of other behaviors.

we didn’t have to be able to talk to each other about our current thoughts and projects, and our memories of how things were, and so forth, our brains wouldn’t waste the time, energy, and gray matter on an edited digest of current activities, which is what our stream of consciousness is.

These machines “we inhabit” simplify things for our benefit: “The experience of will, then, is the way our minds portray their operations to us, not their actual operation”

The key insight is that a module “dumbly, obsessively converts thoughts into linguistic form and vice versa” (Jackendoff 1996). Schematically, a conceptualized thought triggers the production of a linguistic representation that approximates the content of that thought, yielding a reflexive blurt.

There are structural, chemical properties of glucose—mimicked in saccharine and other artificial sweeteners—that cause the sweetness response in our nervous systems, but “the intrinsic, subjective sweetness I enjoy” is not an internal recreation or model of these chemical properties, nor is it a very special property in our non-physical minds that we use to decorate the perceptible things out there in the world. It is no property at all; it is a benign illusion. Our brains have tricked us into having the conviction, making the judgment, that there seems to be an intrinsically wonderful but otherwise undescribable property in some edible things: sweetness. We can recognize it, recall it, dream about it, but we can’t describe it; it is ineffable and unanalyzable.

The price you pay for following Searle’s advice is that you get all your phenomena, the events and things that have to be explained by your theory, through a channel designed not for scientific investigation but for handy, quick-and-dirty use in the rough and tumble of time-pressured life. You can learn a lot about how the brain does it—you can learn quite a lot about computers by always insisting on the desktop point of view, after all—but only if you remind yourself that your channel is systematically oversimplified and metaphorical, not literal. That means you must resist the alluring temptation to postulate a panoply of special subjective properties (typically called qualia) to which you (alone) have access.

The traditional view of free will, as a personal power somehow isolated from physical causation, is both incoherent and unnecessary as a grounds for moral responsibility and meaning.

One can get a sense of this by asking yourself: If—because free will is an illusion—no one is ever responsible for what they do, should we abolish yellow and red cards in soccer, the penalty box in ice hockey, and all the other penalty systems in sports?

Among the artifacts we have created is the concept of God, the Intelligent Designer, in our own image. That’s how much we value the intelligent designers in our societies.

perspicuous.

believe it was John Cage who once told me, “When you start working, everybody is in your studio—the past, your friends, enemies, the art world, and above all, your own ideas—all are there. But as you continue painting, they start leaving, one by one, and you are left completely alone. Then, if you’re lucky, even you leave.” (2011, p. 30)

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There is a living to be made catering to the expressed needs of individual meme seekers,

The real danger, I think, is not that machines more intelligent than we are will usurp our role as captains of our destinies, but that we will over-estimate the comprehension of our latest thinking tools, prematurely ceding authority to them far beyond their competence.

prodigious feats while still being a 98-pound weakling; the second makes you strong enough to do great things on your own. Most of the software that has enhanced our cognitive powers has been of the bulldozer variety, from telescopes and microscopes to genome-sequencers and the new products of deep learning. Could there also be Nautilus-type software for bulking up the comprehension powers of individuals?

Who’s working on this?