The Knowledge Newsletter

In chapter 2, Dennett addresses what he sees as the fundamental “dangerous idea” that Darwin had, namely, speciation through natural selection. He has a very useful section at the beginning on the difference between accidental and essential properties and between real essences and nominal essences. Pre-Darwin, the world was “carved up at the joints” and biological entities were divided up based on what was seen as real essences: essential properties that defined a thing such that absent those properties, the thing ceased to be what it is. Darwin overthrew this type of essentialism. Terms like “natural kinds”– where this term described silos of living things which are not interrelated with each other–no longer described the biological world.

Dennett then goes on to describe natural selection as an algorithmic process by which change occurs in living organisms by a regular, repeated, chance-driven process that always works. Natural selection is essentially a set of algorithms that sort, winnow, and build things (52) but which have no goal or purpose behind them. Dennett makes some effort to present the idea that what seems like complex results can be achieved through very simple steps using algorithms. Natural selection, then, provided Darwin with his mechanism for the diversity which his research produced.

There are a lot of interesting and curious ideas presented in this chapter. Dennett continues to promote the idea that Darwin’s idea is beyond dispute.

“But the fact of speciation itself is incontestable, as Darwin showed, building an irresistible case out of literally hundreds of carefully studied and closely argued instances.” (44)

“To put it bluntly but fairly, anyone today who doubts that the variety of life on this planet was produced by a process of evolution is simply ignorant–inexcusably ignorant, in a world where three out of four people have learned to read and write.” (46)

“It is reasonable to believe that an idea that was ultimately false would surely have succumbed by now to an unremitting campaign of attacks.” (47)

Certainly, this is the point of my research: to see whether the evidence is convincing. But I wonder at the outset if this is just partisan rhetoric or if evolution by natural selection is as conclusive as say the earth going around the sun. My hope is that the rest of Dennett’s book will help provide this strong case he says exists.

Another curiosity in this chapter is that Dennett seems convinced that Darwin made the case for speciation through evolution and for natural selection. The single book The Origin of Species seems to have been sufficient to establish the fact of evolution by natural selection even if it was greatly insufficient to establish the mechanism by which this natural selection occurs. It is striking that one book was able to make a case for an hypothesis that would seem to require evidence from many fields that were not in existence at Darwin’s time. Evolution by natural selection is not a theory like e=mc2 or the existence of the double-helix. It seems to me that evolution by natural selection involves a set of inferences from a tremendous amount of data. Yet Dennett doesn’t say that Darwin set the foundation for this research so that evolution by natural selection could be established but says that Darwin established it with the research that he did.

Perhaps the fact that I find this striking betrays some of my biases and some of the misconceptions that I need to overcome. I have a certain set of expectations about what a theory like evolution would need in order to be “proved.” If those expectations are incorrect, I’m hoping that people like Dennett and others I read will help dispel or modify them.

Interestingly, Dennett says that Darwin didn’t really explain the origin of species. In fact, Dennett seems to say, no one has yet explained it. “Controversy about the mechanisms and principles of speciation still persists, so in one sense neither Darwin nor any subsequent Darwinian has explained the origin of species.” (44) I’m not sure what Dennett means by this.

Algorithms and Natural Selection

This section, it seems to me, is important as a foundation for natural selection and Dennett does his readers a great service by laying it out so plainly. What’s important for my research is that this section doesn’t contain much if any scientific evidence for natural selection as it lays out a philosophical foundation for how natural selection might work. Part of my research goal is to become exposed to the physical evidence for evolution and juxtapose it against the mechanistic models that are more philosophical in nature. Another question I want answered is whether the models are entailed by the physical evidence or if the models are primary and the evidence fits the models (or is made to fit the models).

The model of algorithms that Dennett proposes has three main features.

1. Substrate neutrality. The algorithm is logical in nature, not tied to any particular material per se.

2. Underlying mindlessness. Dennett is unclear here. The feature is described as “mindlessness” but the description is about the process of an algorithm using small, incremental, and fundamentally simple steps to produce very complex results. Of course, this says nothing about mindlessness. That something is simple doesn’t say anything about it not requiring specific and perhaps irreducible features of mind namely intention, goal-directed behavior, persistence, and the like. But I think Dennett’s point is that an algorithm can build on itself to produce complex results from very modest and simple processes. Perhaps a better title for this feature would be “underlying simplicity.”

3. Guaranteed results. An algorithm always produces the same result every time it is executed.

Dennett then formulates Darwin’s fundamental idea thusly: Life on Earth has been generated over billions of years in a single branching tree–the Tree of Life–by one algorithmic process or another.

Dennett’s discussion of how algorithms might work in natural selection is important in that he’s trying to present a foundation for how the process might have worked. Notably, he doesn’t bring in any physical evidence and state that algorithmic processes are demanded by the physical evidence (something I’m hoping he’ll be doing in later chapters). Rather he seems to be summarizing what he believes Darwin proved and concluding that algorithms are the best underlying explanatory model for what Darwin discovered.

Dennett is very clear that the algorithms of natural selection are mindless, goalless, chance processes. This, of course, is key based on a naturalist assumption of the world. Dennett seems to conflate naturalism with Darwinian evolution: the latter does not entail the former. But for Dennett they go hand in hand–not a trivial point.

“Darwin was offering a skeptical world what we might call a get-rich-slow scheme, a scheme for creating Design out of Chaos without the aid of Mind.” (50)

“But a procedure doesn’t fail to be an algorithm just because it is of no conceivable use or value to anyone….Algorithms don’t have to have points or purposes.” (56)

“We can now expose perhaps the most common misunderstanding of Darwinism: the idea that Darwin showed that evolution by natural selection is a procedure for producing Us.” (56, emphasis and capitalization in original)

“Can it [the fancy biosphere] really be the outcome of nothing but a cascade of algorithmic processes feeding on chance? And if so, who designed that cascade? Nobody. It is itself the product of blind, algorithmic process.” (59)

So what Dennett seem to glean from this is that Darwinian natural selection not only describes an algorithmic process for how evolution takes place but also can tell us that this process is not guided by Mind. However, Dennett does little to demonstrate this. In fact, his description of the algorithms of natural selection and how they might work in evolution are not based in physical evidence neither do they seem to demand even prima facie entailments for what is “behind” them. Yet, Dennett seems to think that an algorithmic description of natural selection entails naturalism and, in fact, this was a key driver of Darwin’s idea that makes it dangerous. If Dennett isn’t implying anything as strong as entailment, he certainly sees a strong relation between Darwin’s idea and purposeless processes. I’m not quite sure why. Certainly he hasn’t yet provided any evidence to think that this is the case–in this chapter it’s been mere assertion. My hope is that Dennett will do much more in the rest of his book to support this implication. As it stands now, it is a mere assertion with very little to support it. In fact, based on what Dennett says in this chapter, algorithms make little sense without Mind and, in fact, some of Dennett’s claims seem blatantly contradictory at worse or simply confused or unclear at best.

Natural Selection, Axiology, and Teleology

In his discussion of algorithms, Dennett uses what appears to be some inconsistent language, metaphors, and examples to illustrate the idea. He needs to discuss algorithms particularly with respect to natural selection in terms that do not include even hints of teleology and, it seems to me axiology (it is my view that axiology depends on teleology). He’s already established that Darwin’s dangerous idea implies that purposiveless, mindless, chance forces operating in an algorithmic way developed in small, incremental steps the diverse forms of life we see on earth today. To discuss algorithms consistent with this view then, he needs to avoid language that might imply goals, purpose, value, etc. It seems that Dennett is largely unsuccessful in this chapter to do so.

I understand that in an early chapter like this, Dennett is most likely being a bit loose in his language in order to establish some core ideas. But I do want to track this. If he doesn’t “fix” things, it will hurt his overall argument. I don’t think a consistent theory of evolution will use teleological concepts particularly in it’s more precise descriptions. Here are some examples (among others) of this loose language that Dennett employs.

“But the algorithms that will concern us have nothing particular to do with the number system or other mathematical objects; they are algorithms for sorting, winnowing, and building things.” (52)

“But what, exactly, does this algorithm do? It takes as input a set of competitors and guarantees to terminate by identifying a single winner. But what is a winner? It all depends on the competition.” (53).

“The power of an algorithm to yield something of interest or value is not at all limited to what the algorithm can be mathematically proven to yield in a foolproof way, and this is especially true of evolutionary algorithms.” (57)

“It can be proven mathematically that these rearrangements will tend to get better and better, approaching the optimum or strongest total structure…” (Dennett here is using the example of metal annealing to demonstrate the use of an algorithm. 57,58).

“Here, then, is Darwin’s dangerous idea: the algorithmic level is the level that best accounts for the speed of the antelope, the wing of the eagle, the shape of the orchid, the diversity of species, and the other occasions for wonder in the world of nature.” (59)

Of course, if naturalism is true, then there are no winners or losers in evolutionary process, there are no changes that are more valuable than others, there’s no algorithms that are for any purpose, there’s no sense to be given to notions of “optimal” or “strongest” or any such thing. I suspect that Dennett employs such language (as Dawkins does) simply as a rhetorical device to get some complex ideas across. However, if he doesn’t move away from such language, I think he can easily be accused of being inconsistent with his naturalism. I’ll be anxious to see how if and how he describes evolution without teleology and axiology.

Main takeaway from this chapter is that Dennett sets up a very useful foundation for the mechanism of natural selection. He does not provide much by way of evidence that his idea is true an no evidence that the diversity of life was brought about in the algorithmic way. Again, I hope to discover more along these lines in chapters coming up.

In this chapter Dennett attempts to look at Darwinian evolution through the eyes of what he sees as a persistent explanatory paradigm: the notion of species creation through special design. He does this by very briefly looking at the views of Hume and Locke and showing how though they touched on the abstract possibility of variety through chance and time, they weren’t able to conceptualize the mechanism and so abandoned it. They settled on the conclusion that an intelligent artificer had to create the specificity we see in the world because no unintelligent mechanism for doing so exists.

Dennett seems to have a sub-goal in this chapter of dismantling any vestiges of non-Darwinian explanation but does so mostly through rhetoric as would be expected in an early chapter like this. Little is given evidentially in this introductory chapter but Dennett does lay the rhetoric on thick which creates a certain level of anticipation for what is coming.

With regards to the possibility of Darwinism being wrong he writes, "There are vigorous controversies swirling around in evolutionary theory, but those who feel threatened by Darwinism should not take heart from this fact. Most–if not quite all–of the controversies concern issues that are ‘just science’; no matter which side wins, the outcome will not undo the basic Darwinian idea." (19)

Additionally, he says that the "Darwinian Revolution" will be as much a part of the consciousness of educated people as Copernicus’. "In due course, the Darwinian Revolution will come to occupy a similarly secure and untroubled place in the minds–and hearts–of every educated person on the globe, but today, more than a century after Darwin’s death we still have not come to terms with its mind-boggling implications." (19)

Dennett also uses terms that describe Darwinian evolution (or perhaps more accurately, the neo-Darwinian synthesis) as fairly close to certain.

"The fundamental core of contemporary Darwinism, the theory of DNA-based reproduction and evolution, is now beyond dispute among scientists." (20)

"It took an irresistible parade of hard-won scientific facts to force thinkers to take seriously the weird new outlook that Darwin proposed.  Those who are still ill-acquainted with that beautiful procession can be forgiven their continued allegiance to the pre-Darwinian ideas. And the battle is not yet over; even among scientists, there are pockets of resistance." (21)

"You can either deceive yourself or let others do the dirty work, but there is no intellectually defensible way of rebuilding the might barriers to comprehension that Darwin smashed." (25)

The main takeaway for me from this chapter was that Dennett is essentially setting up his book. There’s very little if anything by way of substantive evidence for evolution and, in fact, interestingly pits Darwinism against theistic special creation for some reason which I find rather odd. I also read the opening chapter to Pinker’s Blank Slate and he did the same thing. A curious way to open philosophy books about Darwinism. But nothing more than a curiosity.

In this series of blogs, I’m going to attempt to lay out what I see as the main arguments of each chapter of Daniel Dennett’s Dariwn’s Dangerous Idea. My goal is to capture how Dennett provides a philosophical justification of Darwinian evolution particularly looking at his theory of agent-less design.

For the last couple of years, as I’ve thought about the public acceptance of Darwinism, I’ve wondered how easy it would be for a non-professional to understand and then rationally accept the main tenets of Darwin’s theory. By Darwinist’s own admission, Darwin’s model seems counter-intuitive in that many biological entities have the appearance of design. Thus, for many, Darwinism has to be learned or has to be accepted on the basis of evidence and argument.

Ostensibly, evidence adequate enough for rational belief exists and arguments both philosophical and scientific are accessible enough that a junior high school student should be able to understand and accept the theory (countering the common sense view that complexity implies agency). One of my goals in this exercise is to test that those claims. Is it possible to boil Dennett’s arguments down enough to create a simple and accessible philosophy of Darwinism that would be understandable and accessible by intelligent students and laymen?

I chose Darwin’s Dangerous Idea (1995, Touchstone) because of it’s importance, because it is presented as a philosophical defense of Darwinism, and because Dennett is such an enjoyable, clear, and thorough writer.