Dennett’s somewhat dangerous idea

The philosopher Daniel Dennett has recently published a memoir and in a review Matthew Lau accuses him of pursuing a ‘dead end social Darwinism’. He says that Dennett has defended the idea of ‘adaptationism’, the view “that all features of an organism must be adapted for some good purpose.” This has been rejected by other scholars of evolution like Stephen Jay Gould and Richard Lewontin who argue that some features did not come into being to serve a specific purpose but were instead accidental byproducts of the evolutionary process. Those two authors gave the image of the spandrels in cathedrals.

In architecture, spandrels are a structural byproduct resulting from the placement a dome on top of four rounded arches. The spandrels fill in the empty space where the arch stops touching the top of the dome, stabilizing the overall structure. In finished cathedrals they are frequently painted and otherwise beautifully ornamented, as in the four famed spandrels of the Cathedral of San Marcos in Venice, Italy, that depict the four biblical rivers (Tigris, Euphrates, Indue, and Nile).

For Gould and Lewontin, if we adopt the adaptationist perspective, we might mistakenly assume the San Marcos spandrels were initially formed to be part of the cathedral’s artwork and miss their origin as necessary structural byproducts.

Lau says that Dennett waged a war against Gould and Lewontin on this issue.

Working within the tradition of analytic philosophy of mind, a strain of thought which developed within the English academy, Dennett has maintained several positions that might strike many outside of the discipline as counterintuitive. Chief amongst these is his denial of the relevance of subjective experience — or “qualia,” as philosophers are fond of calling it — in the study of consciousness, a view which came to prominence mid-century largely thanks to the Oxford don Gilbert Ryle.

More controversially, perhaps, he has denied that Darwin’s theory of natural selection is incompatible with the premodern notion that nature can be understood to have purposes or ends. For Dennett, evolution by natural selection does not abandon what Aristotle called final causes, as Darwin explicitly said it had. Dennett simply replaces the higher intelligence of God, the traditional final cause, with the principle of natural selection.

Accordingly, critics have charged him with “ultra-Darwinism” and “Darwinian fundamentalism.” Dennett’s own description is more accurate. Without irony, he has likened his Darwinism to the adaptationist determinism of Professor Pangloss in Voltaire’s satirical novel Candide. Like Pangloss, Dennett thinks “things cannot be other than what they are.”

The series of events that led Dennett to adopt his extreme and idiosyncratic version of Darwinism as a broad defense of Panglossian adaptationist thinking are alluded to several times in his memoir, but never sketched with full clarity.

Lau says that the political implications of Dennett’s ideas are quite reactionary.

There is also a political dimension to the appeal of Pangloss-style reasoning for Dennett and other contemporary social Darwinists. Pangloss excels at justifying the status quo.

In the larger political and social context of the 1980s and ’90s, when Dennett began his feud with Gould and Lewontin, the US working class was drowning and adaptationism was the underlying assumption of two popular science trends — “sociobiology” and “evolutionary psychology” — that said we should let them sink. Both sociobiology and evolutionary psychology sought to rebrand Darwinism as a defense of the idea of an innate violent, competitive human nature and intrinsic, immutable, “natural” differences between sexual and even racial groups.

Both did as much as any intellectual movement to create the current political climate where government cuts to basic necessities proceed as a matter of course. Adaptationism, Gould’s argued in The Mismeasure of Man, his classic refutation of the view that biology was destiny, helped foster “a historical moment of unprecedented ungenerosity, when a mood for slashing social programs can be so abetted by an argument that beneficiaries cannot be aided due to inborn cognitive limits expressed as low IQ scores.”

I am by no means in a position to judge the merits of adaptationism. I did read two of Dennett’s books Darwin’s Dangerous Idea and Consciousness Explained many years ago and they did not strike me as having the strong social Darwinist themes that Lau claims he espouses. It may be that the negative social Darwinist ideology that Lau points to is itself somewhat like a spandrel, something that Dennett did not consciously espouse but instead came about as a result of his advocacy of adaptationism.

In each of thee two Dennett books that I read, I found one key idea that stayed with me.

In Darwin’s Dangerous Idea it was his use of the metaphor of a ‘universal acid’ to describe the theory of natural selection. By this he meant a powerful acid that is able to eat through the material of any vessel and thus cannot be limited or contained. The implication is that all efforts to limit the scope of evolutionary theory in order to preserve some special place that evolution cannot explain, such as human beings or the mind, are doomed to fail. There is thus no room for any supernatural explanation for any feature of life. This is consistent with Dennett’s own atheist views.

In Consciousness Explained, what struck me was his explanation that the mind is constantly creating multiple drafts of explanations for our experiences and that what we call our ‘memory’ of events is the draft that, for whatever reason, was finally settled on. When we are awake and conscious, what we experience via the senses places strong constraints on the freedom of the mind to create scenarios. But when we are asleep and those senses (especially the powerful visual one) go dormant, then the mind runs free to manufacture all kinds of drafts, which explains why our dreams can be so bizarre.

When it comes to the question of free will, Dennett belongs to the camp of those materialists known as ‘compatibilists’, who think that even though we are material entities with no non-material mind, yet we do have free will. I find his views on this to be incoherent. In an online debate with another philosopher Greg Caruso (that I wrote about here) Dennett defended his view but I thought that Caruso did a good job of exposing its weaknesses.


  1. garnetstar says

    I will just say, everyone knows that natural selection isn’t the only method of evolution, one other being genetic drift, which is random. With randomness, certainly things could be different than what they are, and not everything is an adaptation.

    This is a fundamental flaw in the basic premises of evolutionary psychology, that everything now seen is an adaptation that was optimized by natural selection.

    So, Dennett must know this, but chooses to ignore it, because it contradicts the theory that he *wants* to be true?

  2. says

    For Dennett, evolution by natural selection does not abandon what Aristotle called final causes, as Darwin explicitly said it had. Dennett simply replaces the higher intelligence of God, the traditional final cause, with the principle of natural selection.

    This is utter nonsense. God is believed to be a sentient being who consciously conceives of objectives and does things in pursuit of such objectives. Whatever such a God has decided to achieve is, by definition, the “final cause.” Natural selection, however, is not a sentient being at all, therefore it doesn’t consciously conceive of objectives; therefore there it has no “final cause” to replace the will of a god.

    And besides, all that “final cause” rhetoric is already discredited, having been used by pompous bigots to rationalize their hatred of LGBT+ people.

    So it kinda looks like Dennett is the last of the “Four Horsemen” to ride off a cliff and discredit himself with already-discredited backward reasoning. Those “New Atheists” got old pretty quick, didn’t they?

  3. Pierce R. Butler says

    Dennett did score a solid hit against Gould by revealing architectural history showing that spandrels had fit into original designs from way back, which at least demolished the analogy, if not the core point.

    He also, as the backlash against the “four horsemen” got rolling, emitted a shallow and uninformed slap against “radical feminism” -- and then (probably advised by his colleagues at Tufts University) alone among the four had the sense to shut up.

  4. file thirteen says

    @gartnerstar #1:

    Genetic drift is the random change of genes between generations, without which there would be no evolution, offspring being effectively clones of their parents. But it’s not a competitor to natural selection. Natural selection is the fundamental driver for all types of evolution, not just that of life, and I can’t imagine a changing universe without it applying. It would be like a universe without arithmetic.

  5. file thirteen says

    @garnetstar #1:

    On reflection, I might have misunderstood you. I agree that not every change needs to be adaptive. In addition, natural selection is only optimal in an unchanging environment. As the environment changes, natural selection’s pull swings in wildly different directions. Some previously near-irrelevant genes become heavily selected for (or against), some no longer matter much.

  6. Rob Grigjanis says

    file thirteen @5:

    Genetic drift is the random change of genes between generations, without which there would be no evolution

    What about mutation?

  7. file thirteen says


    Mutation is the individual process, genetic drift the result over populations, so part and parcel or have I misunderstood (again)?

  8. Holms says

    Pretty much. Mutation is the spontaneous change of any DNA sequence, while genetic drift is the spread of genetic sequences through a population attributable to chance alone.

  9. another stewart says

    Natural selection is the name we give to the process that causes changes in gene pools through differential reproductive success causally correlated with genotype, and to the result of that process. Genetic drift is the name we give to the process that causes changes in gene pools through differential reproductive success NOT causally correlated with genotype, and to the result of that process. (Natural selection dominates for large population sizes and strong selection coefficients, and genetic drift for small population sizes and weak selection coefficients.)
    How finely you slice up evolutionary processes is a matter of taste, but commonly 4 categories are used; the other two being mutation and gene flow. Any one of these can result in evolution, at least on the small scale. What is more of an open question is whether in principal any could be excluded, and a comparable long term result obtained. In the long run mutation is needed as as source of variation. (In its absence the pool of variation the enables gene flow would be exhausted.) Natural selection is need as the filtering capabilities of genetic drift are limited. Introgression of various forms is observed to be an important process in evolution (especially in plants), so it seems unlikely that we could do without gene flow. It’s the necessity of genetic drift that I find less clear cut -- does it potentiate the other processes by providing a more varied substrate for the other processes to act upon.
    You can have genetic drift without mutation (and gene flow); the effect would be that in the absence of frequency dependent selection, or temporally and spatially varying selection, the population would end up with fixed homozygous alleles at all loci, i.e. all individuals genetically identical.
    It’s not clear to me what genetic drift is intended to reference in 5 above, but I suspect it is not the usual conception. It could be mutation; it could be recombination (chromosome assortment and crossing over); it could be something else. One could conceive of recombination as a source of variation, placing it with mutation and geneflow, or if you take a genocentric view as differential replication of genes, placing it with genetic drift; regardless it is not the whole of genetic drift. (Note that evolution works just fine in asexually reproducing species, where, apart from mutations, offspring are genetically identical to parents.)
    In the real world you can’t turn off any of the 4 processes (though gene flow can be rendered negligible) and the result depends on their interactions. But it’s still helpful for the understanding of the overall process to consider what the results of each would be in isolation. (But don’t be like creationists and conclude that because neither the production of variation or the filtering of gene pools on their own is sufficient to account for evolution in the large the combination of the two can’t.)

  10. seachange says

    I got accused of “scientism” by philosophers who were using the word like bullies use “you’re stupid” on the playground, and Dennett was the guy they hated. That is to say they didn’t (necessarily) think I was stupid, they were calling me names. Only they were being oh so erudite and sesqipedalian about it. So I read him a lot. At the time he was the only philosopher I could find who remembered that science came from natural philosophy.

    I didn’t get anything like what Lau said from the works of Dennett that I read? Most users of the blictri gavagai colorless green ideas sleep furiously word “qualia” are of the name-calling sort, and who also played philosophical-zombie, trolley-problems, and name-calling games a lot. I did indeed find his ideas useful in taking these guys apart and revealing what useless/harmful gasbags they were.

    PZ has talked about multiple human intelligences and how there is strong scientific evidence for at least fourteen of them. A lawyer in court can try to use language to sway you from prioritizing one module of your brain over another so that similar facts can come out with different results. Dennet (and, apparently Lau) seem to want to remain ignorant of this.

  11. Pierce R. Butler says

    FTR: The Freedom From Religion Foundation’s weekly e-newsletter reports that Daniel Dennett died today at age 82.

  12. Owlmirror says


    It may be that Dennett’s views on evolution is being misrepresented in Lau’s review.

    Lau links to Stephen J Gould’s response in the NYRB. Clicking on Gould’s name shows all of his articles in the NYRB — including one where Dennett responded to Gould’s response.

    Dennett writes:

    Let me say a word about “Darwinian fundamentalism.” Nonsense. I do not espouse the preposterous views Gould attributes to this mythic creed. Gould labors to create a caricature of the “strict” adaptationist, a type that occurs nowhere in nature and is explicitly disavowed, at length, by me (Darwin’s Dangerous Idea, pp. 55, 238-261, 302-305, 326-328, and elsewhere). In fact, the passage from my book which Gould uses to anchor his fantasy is misquoted by him. It is adaptationist thinking, not “adaptation, natural selection’s main consequence,” that I say plays a crucial and ubiquitous role in analysis, and so it does, even though, as I stress again and again, there are plenty of other factors (comets, and other catastrophes, for instance) that may well play the predominant causal role in particular cases. What is amazing is that Gould wrests this quotation from the very section (pp. 238-261) in which I attempt to undo the travesty of Gould’s previous efforts over the years to caricature adaptationist thinking.

    This was not the only exchange involving Dennett in the NYRB — a few years earlier, Gould wrote a critical review of Helena Cronin’s book “The Ant and the Peacock: Altruism and Sexual Selection from Darwin to Today”, and received responses from John Maynard Smith and Daniel Dennett.

    Lau appears to be continuing a tradition of sniping at the author in reviews and similar essays, taking a very pro-Gould and anti-Dennett stance, now that Gould is no longer alive to do so himself. While it may not be entirely unjustified, I would be reluctant to conclude that Dennett believes about evolution what Lau says he does, based solely on Lau’s claims.

    On the other hand, I often find Dennett’s claims confusing. Frex, what is the difference between “adaptionist thinking” and “adaptation”, such that one phrasing is right and the other crucially wrong? It’s certainly not obvious to a casual reader like myself.

    Of course, Dennett is not the only one who has made confused and confusing claims. Can’t we make an effort to be clear?

  13. consciousness razor says

    Owlmirror, #14:

    Of course, Dennett is not the only one who has made confused and confusing claims. Can’t we make an effort to be clear?

    I could try. You know, he at least presented himself as folksy and vernacular, just a mere distributor of brain tools which are meant for public use and working under cover as Santa Claus.

    But then … it’s all Greek for many people, and the focus at least seemed to shift to those in the inner circle more often than necessary. That’s a lot of idle speculation that he nonetheless doesn’t (or does?) want to be totally discredited, at least not before he got a chance to take a swing. Confusing “confusion” and “fusion” is another one that could get out of hand fast. Sometimes confusion is okay though.

    He didn’t think everything is biology. I’m fairly sure of that much. That seems like a shallow way to put it. But how much “race science” do we all need to wade through before we can finally get to the real point…?

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