Daniel C. Dennett

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.

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.

The earth has grown a nervous system, and it's us.

[I]t makes little difference where we draw the line between the pruning and shaping [of behavior] by natural selection which is genetically transmitted to offspring (the wiring you are born with), and the pruning and shaping that later takes place in the individual (the rewiring you end up with, as a result of experience or training). nature and nurture blend seamlessly together.

I was once interviewed in Italy and the headline of the interview the next day was wonderful. I saved this for my collection it was... "YES we have a soul but it's made of lots of tiny robots" and I thought that's exactly right. Yes we have a soul, but it's mechanical. But it's still a soul, it still does the work that the soul was supposed to do. It is the seat of reason. It is the seat of moral responsibility. It's why we are appropriate objects of punishment when we do evil things, why we deserve the praise when we do good things. It's just not a mysterious lump of wonder stuff... that will out live us.

[I]f you want to reason about faith, and offer a reasoned (and reason-responsive) defense of faith as an extra category of belief worthy of special consideration, I'm eager to [participate]. I certainly grant the existence of the phenomenon of faith; what I want to see is a reasoned ground for taking faith as a way of getting to the truth, and not, say, just as a way people comfort themselves and each other (a worthy function that I do take seriously). But you must not expect me to go along with your defense of faith as a path to truth if at any point you appeal to the very dispensation you are supposedly trying to justify. Before you appeal to faith when reason has you backed into a corner, think about whether you really want to abandon reason when reason is on your side. You are sightseeing with a loved one in a foreign land, and your loved one is brutally murdered in front of your eyes. At the trial it turns out that in this land friends of the accused may be called as witnesses for the defense, testifying about their faith in his innocence. You watch the parade of his moist-eyed friends, obviously sincere, proudly proclaiming their undying faith in the innocence of the man you saw commit the terrible deed. The judge listens intently and respectfully, obviously more moved by this outpouring than by all the evidence presented by the prosecution. Is this not a nightmare? Would you be willing to live in such a land? Or would you be willing to be operated on by a surgeon you tells you that whenever a little voice in him tells him to disregard his medical training, he listens to the little voice? I know it passes in polite company to let people have it both ways, and under most circumstances I wholeheartedly cooperate with this benign agreement. But we're seriously trying to get at the truth here, and if you think that this common but unspoken understanding about faith is anything better than socially useful obfuscation to avoid mutual embarrassment and loss of face, you have either seen much more deeply into the issue that any philosopher ever has (for none has ever come up with a good defense of this) or you are kidding yourself.

Evolution is all about processes that almost never happen. Every birth in every lineage is a potential speciation event, but speciation almost never happens, not once in a million births. Mutation in DNA almost never happens -- not once in a trillion copyings -- but evolution depends on it. Take the set of infrequent accidents -- things that almost never happen -- and sort them into the happy accidents, the neutral accidents, and the fatal accidents; amplify the effects of the happy accidents -- which happens automatically when you have replication and competition -- and you get evolution.

The trouble with the canons of scientific evidence [...] is that they virtually rule out the description of anything but oft-repeated, oft-observed, stereotypic behavior of a species, and this is just the sort of behavior that reveals no particular intelligence at all - all this behavior can be more or less plausibly explained as the effects of some humdrum combination of "instinct" or tropism and conditioned response. It is the novel bits of behavior, the acts that couldn't plausibly be accounted for in terms of prior conditioning or training or habit, that speak eloquently of intelligence; but if their very novelty and unrepeatability make them anecdotal and hence inadmissible evidence, how can one proceed to develop the cognitive case for the intelligence of one's target species?

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!"

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.)*

Do I worship modern medicine? Is science my religion? Not at all; there is no aspect of modern medicine or science that I would exempt from the most rigorous scrutiny, and I can readily identify a host of serious problems that still need to be fixed. That's easy to do, of course, because the worlds of medicine and science are already engaged in the most obsessive, intensive, and humble self-assessments yet known to human institutions, and they regularly make public the results of their self-examinations. Moreover, this open-ended rational criticism, imperfect as it is, is the secret of the astounding success of these human enterprises. There are measurable improvements every day.

Experience teaches...that there is no such thing as a thought experiment so clearly presented that no philosopher can misinterpret it...

Unpredictability is in general a fine protective feature, which should never be squandered but always spent wisely. There is much to be gained from communication if it is craftily doled out - enough truth to keep one's credibility high but enough falsehood to keep one's options open. (This is the first point of wisdom in the game of poker: he who never bluffs never wins; he who always bluffs always loses.)

There is a familiar trio of reactions by scientists to a purportedly radical hypothesis: (a) "You must be out of your mind!", (b) "What else is new? Everybody knows that!", and, later - if the hypothesis is still standing - (c) "Hmm. You *might* be on to something!" Sometimes these phases take years to unfold, one after another, but I have seen all three emerge in near synchrony in the course of a half-hour's heated discussion following a conference paper.

Remember Marxism? It used to be a sour sort of fun to tease Marxists about the contradictions in some of their pet ideas. The revolution of the proletariat was inevitable, good Marxists believed, but if so, why were they so eager to enlist us in their cause? If it was going to happen anyway, it was going to happen with or without our help. But of course the inevitability that Marxists believe in is one that depends on the growth of the movement and all its political action. There were Marxists working very hard to bring about the revolution, and it was comforting to them to believe that their success was guaranteed in the long run. And some of them, the only ones that were really dangerous, believed so firmly in the rightness of their cause that they believed it was permissible to lie and deceive in order to further it. They even taught this to their children, from infancy. These are the "red-diaper babies," children of hardline members of the Communist Party of America, and some of them can still be found infecting the atmosphere of political action in left-wing circles, to the extreme frustration and annoyance of honest socialists and others on the left.

We live in a world that is subjectively open. And we are designed by evolution to be "informavores," epistemically hungry seekers of information, in an endless quest to improve our purchase on the world.

Much of the controversy and anxiety that has enveloped Darwin's idea ... can be understood as a series of failed campaigns to contain Darwin;s idea within some acceptably "safe" and merely partial revolution. Cede some or all of modern biology to Darwin, perhaps, but hold the line there! Keep Darwinian thinking out of cosmology, out of psychology, out of human culture, out of ethics, politics, and religion! In these campaigns, many battles have been won by the forces of containment: flawed applications of Darwin's idea have been exposed and discredited, beaten back by the champions of the pre-Darwinian tradition. But new waves of Darwinian thinking keep coming.

Political correctness, in the extreme versions worthy of the name, is antithetical to almost all surprising advances in thought. We might call it eumemics, since it is, like the extreme eugenics of Social Darwinists, an attempt to impose myopically derived standards of safety and goodness on the bounty of nature. Few today - but there are a few - would brand all genetic counseling, all genetic policies, with the condemnatory title of eugenics.

People ache to believe that we human beings are vastly different from all other species - and they are right! We are different. We are the only species that has an extra medium of design preservation and design communication: culture. ... We have language, the primary medium of culture... In a few short millennia - a mere instant in biological time - we have already used our new exploration vehicles to transform not only our planet but the very process of design development that created us.

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.