Daniel Dennett Quotes

The fundamental core of contemporary Darwinism, the theory of DNA-based reproduction and evolution, is now beyond dispute among scientists. It demonstrates its power every day, contributing crucially to the explanation of planet-sized facts of geology and meteorology, through middle-sized facts of ecology and agronomy, down to the latest microscopic facts of genetic engineering. It unifies all of biology and the history of our planet into a single grand story. Like Gulliver tied down in Lilliput, it is unbudgable, not because of some one or two huge chains of argument that might — hope against hope — have weak links in them, but because it is securely tied by thousands of threads of evidence anchoring it to virtually every other area of human knowledge. New discoveries may conceivably lead to dramatic, even "revolutionary" shifts in the Darwinian theory, but the hope that it will be "refuted" by some shattering breakthrough is about as reasonable as the hope that we will return to a geocentric vision and discard Copernicus.

Biology is Engineering

from Chapter 1, "Is Nothing Sacred", p. 21-22:

But if we ask where precisely in the brain that point of view is located, the simple assumptions that work so well on larger scales of space and time break down. It is now quite clear that there is no single point in the brain where all information funnels in, and this fact has some far from obvious consequences.

Wherever there is a conscious mind, there is a point of view. A conscious mind is an observer, who takes in the information that is available at a particular (roughly) continuous sequence of times and places in the universe. A mind is thus a locus of subjectivity, a thing it is like something to be (Farrell, 1950, Nagel, 1974). What it is like to be that thing is partly determined by what is available to be observed or experienced along the trajectory through space-time of that moving point of view, which for most practical purposes is just that: a point. For instance, the startling dissociation of the sound and appearance of distant fireworks is explained by the different transmission speeds of sound and light, arriving at the observer (at that point) at different times, even though they left the source simultaneously.

I have grown accustomed to the disrespect expressed by some of the participants for their colleagues in the other disciplines. "Why, Dan," ask the people in artificial intelligence, "do you waste your time conferring with those neuroscientists? They wave their hands about 'information processing' and worry about where it happens, and which neurotransmitters are involved, but they haven't a clue about the computational requirements of higher cognitive functions." "Why," ask the neuroscientists, "do you waste your time on the fantasies of artificial intelligence? They just invent whatever machinery they want, and say unpardonably ignorant things about the brain." The cognitive psychologists, meanwhile, are accused of concocting models with neither biological plausibility nor proven computational powers; the anthropologists wouldn't know a model if they saw one, and the philosophers, as we all know, just take in each other's laundry, warning about confusions they themselves have created, in an arena bereft of both data and empirically testable theories. With so many idiots working on the problem, no wonder consciousness is still a mystery. All these charges are true, and more besides, but I have yet to encounter any idiots. Mostly the theorists I have drawn from strike me as very smart people – even brilliant people, with the arrogance and impatience that often comes with brilliance – but with limited perspectives and agendas, trying to make progress on the hard problems by taking whatever shortcuts they can see, while deploring other people's shortcuts. No one can keep all the problems and details clear, including me, and everyone has to mumble, guess and handwave about large parts of the problem.

In a Thumbnail Sketch here is [the Multiple Drafts theory of consciousness] so far: There is no single, definitive "stream of consciousness," because there is no central Headquarters, no Cartesian Theatre where "it all comes together" for the perusal of a Central Meaner. Instead of such a single stream (however wide), there are multiple channels in which specialist circuits try, in parallel pandemoniums, to do their various things, creating Multiple Drafts as they go. Most of these fragmentary drafts of "narrative" play short-lived roles in the modulation of current activity but some get promoted to further functional roles, in swift succession, by the activity of a virtual machine in the brain. The seriality of this machine (its "von Neumannesque" character) is not a "hard-wired" design feature, but rather the upshot of a succession of coalitions of these specialists. The basic specialists are part of our animal heritage. They were not developed to perform peculiarly human actions, such as reading and writing, but ducking, predator-avoiding, face-recognizing, grasping, throwing, berry-picking, and other essential tasks. They are often opportunistically enlisted in new roles, for which their talents may more or less suit them. The result is not bedlam only because the trends that are imposed on all this activity are themselves part of the design. Some of this design is innate, and is shared with other animals. But it is augmented, and sometimes even overwhelmed in importance, by microhabits of thought that are developed in the individual, partly idiosyncratic results of self-exploration and partly the predesigned gifts of culture. Thousands of memes, mostly borne by language, but also by wordless "images" and other data structures, take up residence in an individual brain, shaping its tendencies and thereby turning it into a mind.

As Akins observes, it is not the point of our sensory systems that they should detect "basic" or "natural" properties of the environment, but that they should serve our "narcissistic" purposes in staying alive; nature doesn't build epistemic engines.

Minds are in limited supply, and each mind has a limited capacity for memes, and hence there is considerable competition among memes for entry in as many minds as possible. This competition is the major selective force in the memosphere, and, just as in the biosphere, the challenge has been met with great ingenuity. For instance, whatever virtues (from our perspective) the following memes have, they have in common the property of having phenotypic expressions that tend to make their own replication more likely by disabling or preempting the environmental forces that would tend to extinguish them: the meme for faith, which discourages the exercise of the sort of critical judgment that might decide that the idea of faith was, all things considered a dangerous idea; the meme for tolerance or free speech; the meme of including in a chain letter a warning about the terrible fates of those who have broken the chain in the past; the conspiracy theory meme, which has a built-in response to the objection that there is no good evidence of a conspiracy: "Of course not – that's how powerful the conspiracy is!" Some of these memes are "good" perhaps and others "bad"; what they have in common is a phenotypic effect that systematically tends to disable the selective forces arrayed against them. Other things being equal, population memetics predicts that conspiracy theory memes will persist quite independently of their truth, and the meme for faith is apt to secure its own survival, and that of the religious memes that ride piggyback on it, in even the most rationalistic environments. Indeed, the meme for faith exhibits frequency-dependent fitness: it flourishes best when it is outnumbered by rationalistic memes; in an environment with few skeptics, the meme for faith tends to fade from disuse.

Are zombies possible? They're not just possible, they're actual. We're all zombies.* Nobody is conscious – not in the systematically mysterious way that supports such doctrines as epiphenomenalism. * It would be an act of desperate intellectual dishonesty to quote this assertion out of context!

Up till now [the development of proto-consciousness], we can suppose, nervous systems solved the "Now what do I do?" problem by a relatively simple balancing act between a strictly limited repertoire of actions – if not the famous four F's (fight, flee, feed, or mate), then a modest elaboration of them.

Philosophers' Syndrome: mistaking a failure of the imagination for an insight into necessity.

A neurosurgeon once told me about operating on the brain of a young man with epilepsy. As is customary in this kind of operation, the patient was wide awake, under only local anesthesia, while the surgeon delicately explored his exposed cortex, making sure that the parts tentatively to be removed were not absolutely vital by stimulating them electrically and asking the patient what he experienced. Some stimulations provoked visual flashes or hand-raisings, others a sort of buzzing sensation, but one spot produced a delighted response from the patient: "It's 'Outta Get Me' by Guns N' Roses, my favorite heavy metal [sic] band!" I asked the neurosurgeon if he had asked the patient to sing or hum along with the music, since it would be fascinating to learn how "high fidelity" the provoked memory was. Would it be in exactly the same key and tempo as the record? Such a song (unlike "Silent Night") has one canonical version, so we could simply have superimposed a recording of the patient's humming with the standard record and compare the results. Unfortunately, even though a tape recorder had been running during the operation, the surgeon hadn't asked the patient to sing along. "Why not?" I asked, and he replied: "I hate rock music!" Later in the conversation the neurosurgeon happened to remark that he was going to have to operate again on the same young man, and I expressed the hope that he would just check to see if he could restimulate the rock music, and this time ask the fellow to sing along. "I can't do that," replied the neurosurgeon, "since I cut out that part." "It was part of the epileptic focus?" I asked, and he replied, "No, I already told you – I hate rock music."

I find it breathtaking […] that when musical composition competitions are held, the contestants often do not submit tapes or records (or live performances) of their works they submit written scored, and the judges confidently make their aesthetic judgements on the basis of just reading the scores and hearing the music in their minds. How good are the best musical imaginations? Can a trained musician, swiftly reading a score tell just how that voicing of dissonant oboes and flutes over the massed strings will sound?

The juvenile sea squirt wanders through the sea searching for a suitable rock or hunk of coral to cling to and make its home for life. For this task, it has a rudimentary nervous system. When it finds its spot and takes root, it doesn't need its brain anymore, so it eats it! (It's rather like getting tenure.)* * The analogy between the sea squirt and the associate professor was first pointed out, I think, by the neuroscientist Rodolfo Llinas.