Philosopher
Daniel C. Dennett has long been regarded as one of the top apologists of
materialism, so no doubt his fans must have had high hopes for his
new tome, entitled From Bacteria to Bach and Back: The Evolution of
Minds. But the book fails to give us anything like a coherent
plausible explanation for the origin of human mentality.
The
first part of the book consists largely of Dennett pontificating
about natural selection, which Dennett inaccurately portrays as some
great creative force. What we have are the typical exaggerations and
misstatements of Darwin fanboys on this topic, and they are delivered
most dogmatically, with very little supporting evidence. Dennett
provides no examples of innovative complex macroscopic features of organisms that have
been proven to have originated by natural selection and random
mutations – because no such proof has been produced by
scientists. Contrary to Dennett's assertions, natural selection is merely a kind of pruning effect or filter that gets rid of bad
designs, not something that has any power to produce complex good designs.
Natural selection may describe survival of the fittest, but does not
explain the arrival of the fittest.
The
diagram above tells the true nature of natural selection. It is not
something that explains the appearance of the yellow circles in the
diagram, but merely explains how the red circles got filtered out.
On
page 43, Dennett claims that natural selection is a collection of
algorithms, and on page 384 he claims that “natural selection is a
substrate-neutral family of algorithms.” These claims are false. An
algorithm is a sequential set of steps to follow to achieve a
particular result, being something that is processed by either a mind
or a computer. Natural selection is simply the observational fact of
survival of the fittest, the fact that fit things survive longer and
reproduce more than unfit things. Natural selection is neither an
algorithm nor a collection of algorithms.
The
great question about natural selection is: how could this mere
pruning effect (which is merely a filter) ever explain the
astonishingly complex and coordinated biological complexity we see in
the real world? Dennett doesn't explain this in any substantive way,
although he very clumsily provides a visual to try to warm us up to
the idea that something apparently designed can be produced
naturally. He gives us a Science magazine photo showing some
circles of stones, and discusses a geological theory that supposedly
naturally explains these circles as natural geological effects. The
problem with that, of course, is that the complexity we see in
biological systems is trillions of times more complex (and
gigantically more coordinated) than some little circles of stones.
Later
on Dennett has a chapter with the rather silly title “Brains Made
of Brains.” On page 155 he advances the frequently stated
misconception that the brain is massively parallel. Getting things
all mixed up, he states, “Brains are parallel (they execute many
millions of 'computations' simultaneously, spread over the whole
fabric of the brain); computers are serial (they execute one single
simple command after another, a serial single-file stream of computations that
makes up for its narrowness by its blinding speed).” To the
contrary, human brains do not do many computations simultaneously,
and humans can do only one math computation at a time; conversely you
can buy desktop computers that actually do dual-processing which is
parallel processing.
Sounding
like a real Richard Dawkins fanboy, Dennett goes on to a long
enthusiastic discussion of Dawkins' idea of memes. But such a
discussion is not something that helps at the job of explaining the
appearance of human minds. Memes are ideas, and do nothing to
explain how we have a mind that produces ideas.
Dennett
seems to dodge or largely ignore the main difficulties of explaining
the origin of minds such as ours. One of the principal difficulties
is the fact that according to the prevailing account, in a period of
a few million years hominid ancestors evolved into large-brained
humans; but the population of these hominids was supposedly very
small when this happened, being no greater than 20,000 or so. The
problem is that such a progression would have required many beneficial mutations, and the number of mutations in a population is
proportional to the size of the population; so beneficial random mutations in a small population should be incredibly rare. As discussed in this scientific paper, calculations based on
known mutation rates suggest that a few million years is way, way too
small a time to allow for so many favorable mutations in such a small
population, which we should not have expected to see in even 500
million years of time. This “waiting time” problem is one of the
chief difficulties of explaining the origin of human minds. But
Dennett simply ignores it.
Another
set of difficulties lies in the fact that our minds have quite a few
characteristics that we cannot plausibly explain by appealing to
natural selection. As was pointed out at length in this essay by the co-founder of
the theory of natural selection (Alfred Russel Wallace), the human
mind has many capabilities and abilities that seem to be impossible
to explain by means of natural selection, because they are things
that do not improve an organism's chance of surviving in the wild.
Among these things are aesthetic abilities, insight, curiosity,
philosophical abilities, language abilities, mathematical abilities,
spirituality, and altruism. As argued here, none of these things
would make an organism significantly more likely to survive in the
wild, so we cannot explain them by the idea of natural selection. So
how did we get them? Dennett fails to provide an answer.
In my
essay I referred to in the previous paragraph, I didn't even mention
an additional problem: the difficulty of explaining man's very
long-term memory. Humans have memories that can reliably recall
things that happened 50 years ago, but this is very much a “luxury
feature” exceeding by a factor of 25 what is necessary for
survival. An organism would do just fine in the wild remembering
things for only one or two years, by just remembering all of the
skills and body/location memories it used in the last year or two.
Besides being inexplicable from a Darwinian standpoint, our minds
capable of storing memories for 50 years are inexplicable from a
neurological standpoint. The leading theory of memory involves the
idea that synapses store memories. But that doesn't work, because
(as discussed here) synapses are subject to very rapid molecular turnover and structural
turnover which should make them unsuitable for storing memories for
longer than a year.
As far
as I can see Dennett completely ignores the whole issue of explaining
human memory, not even trying to explain it. He also seems to dodge
or largely ignore the main philosophical issue involved in explaining
human minds – the issue of how it could possibly be that a merely
physical thing could produce the rich mental reality of our
consciousness. Philosophers have long smelled an inherent
implausibility that any merely physical thing (no matter how
complicated its arrangement) could yield the very non-physical thing
we call the human mind. For a physical brain to produce Mind seems
rather like a stone pouring out blood when you squeeze it.
The
only way Dennett seems to handle this issue is through a gigantic
cop-out. His fourteenth chapter is entitled, “Consciousness as an
Evolved User-Illusion.” I won't describe his nonsensical reasoning,
but will merely note that the moment a thinker starts claiming that
consciousness is an illusion, he has revealed the intellectual
bankruptcy and unreasonableness of his assumptions.
In the
last four pages of his book, Dennett provides a grand summary of his
explanation of our minds. The summary is an incoherent mess. It
starts with the last of his numerous appeals to the authority of
Darwin, the type of Darwin showed nature is purposeless talk
that thinkers like Dennett give like some Freudian reverently stating
Freud showed our anxieties are caused by our childhood sex
conflicts. Then Dennett goes on to mention Alan Turing (who helped
get computers started) and Shannon (who made contributions to
information theory). This seems more like name-dropping than
something that helps in explaining our minds. Computers have nothing
to do with explaining the origin of human minds. Giving a final
salute to Dawkins, Dennett also mentions in italics “words
striving to reproduce,” which is a strange personification that
does nothing to clarify the origin of our minds. Then in the book's
second-to-last paragraph he reiterates his cop-out claim that
consciousness is a “user-illusion.”
Of
course, by claiming that consciousness is just an illusion, a writer
has a convenient excuse for failing to explain it, on kind of the
grounds of “there's pretty much nothing there to explain.” It's
convenient Dennett has such an excuse, as his book sheds little
light upon the origin of our minds.
Postscript: Today I am reading Evolution and Ecology: The Pace of Life by Cambridge University biology professor K. D. Bennett. Referring to speciation (the origin of species), this mainstream authority says on page 175, "Natural selection has been shown to have occurred (for example, among populations of Darwin's finches), but there is no evidence that it accumulates over longer periods of time to produce speciation in the Darwinian sense." So why have we been so often told the opposite by Darwin enthusiasts?
Postscript: Today I am reading Evolution and Ecology: The Pace of Life by Cambridge University biology professor K. D. Bennett. Referring to speciation (the origin of species), this mainstream authority says on page 175, "Natural selection has been shown to have occurred (for example, among populations of Darwin's finches), but there is no evidence that it accumulates over longer periods of time to produce speciation in the Darwinian sense." So why have we been so often told the opposite by Darwin enthusiasts?
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