Category Archives: Evolution

The Design Argument

The fifth of Kreeft & Tacelli’s 20 arguments for the existence of God is the Design Argument. This is perhaps the most important argument in the whole collection. It’s the one that seems the most obviously valid to most theists and the most obviously invalid to most atheists, who consider it to have been definitively debunked by Darwin.

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Summary of the argument

  1. The universe shows a remarkable amount of intelligible order.
  2. Either this order came about by chance, or it was designed by something intelligent.
  3. Chance is not a credible explanation because “we can understand chance only against a background of order.” Darwin’s theory of the nonrandom survival of random variation also assumes the prior existence of intelligible order (“The survival of the fittest presupposes the arrival of the fit”) and can therefore not explain it.
  4. Therefore, the universe was designed by something intelligent.
  5. In order to have designed the entire universe, the designers must exist outside the universe and be non-physical in nature. It is therefore natural to identify them — or, rather, “him” — with God.

The intelligent design (ID) hypothesis is usually presented as a stripped-down version of creationism, an alternative to Darwin’s theory of the origin of species. However, while K & T appear to be evolution skeptics themselves (they cite Michael Denton and Phillip E. Johnson with approval), they maintain that the Design Argument would still be just as valid and convincing if the Darwinian hypothesis were true. In my critical comments below, I will therefore assume biological orthodoxy: that all organisms arose from a common ancestor via descent with modification driven primarily by natural selection.

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Chance and design do not exhaust the possibilities.

Why does my reflection look like my face? Should we ascribe the correspondence to chance or design? (Note that I am not asking about the origin of the reflective surface, which could just as well be a naturally occurring puddle as an intelligently designed mirror, but about the reflection itself.) We unhesitatingly ascribe the resemblance between Arrangement in Grey and Black No. 1 and Anna Whistler to design, and my reflection resembles my face far more exactly than any portrait resembles its subject — so should we infer that there is some unseen intelligent agent busily designing all the reflections we see? After all, the only other option — that the incredibly detailed, point-by-point correspondence between my face and my reflection is just a coincidence — is even more absurd.

Clearly this is a false dichotomy, and the true explanation for the correspondence is what we might call blind regularity. (Another term which suggests itself, necessity, carries too much philosophical baggage to be suitable here.)

A detailed discussion of chance, regularity, and design is beyond the scope of this post (as I realized after typing out a very long tangent on the subject, which I decided not to include). The point I want to make is just that “chance,” as it is used in this argument, doesn’t really mean chance; it covers anything that isn’t intelligent design, including mindless adherence to the laws of physics. The dichotomy K & T are advocating would force us to say either that the sun always rises in the east and never in the west just “by chance” — an absurdly improbable coincidence — or else that it is guided in its path by an intelligent agent — Phoebus in his chariot, essentially. The parody theory of “Intelligent Falling” comes to mind.

So, wherever K & T write “chance,” read “unintelligent forces” — not necessarily chance as that word is ordinarily understood.

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What Darwinism presupposes — and what it doesn’t

“The survival of the fittest presupposes the arrival of the fit” sounds right at first but is actually a misrepresentation of Darwin’s theory. K & T write:

If the Darwinian theory has shown anything, it has shown, in a general way, how species may have descended from others through random mutation; and how survival of these species can be accounted for by natural selection—by the fitness of some species to survive in their environment.

This makes it sound as if natural selection plays no role in the actual origin of new species but serves only to explain why some species, after having come into existence by pure chance, continue to survive. This is obviously not what Darwin had in mind when he wrote On the Origin of Species by Means of Natural Selection. Although it is true that natural selection is a wholly negative process, weeding out some of what comes into being by random mutation, it nevertheless plays a creative role. Without natural selection, new “fit” species would never come into existence in the first place because every random change for the better would be canceled out by thousands of random changes for the worse. Natural selection functions as a ratchet, preserving only the good changes and allowing them to accumulate in a way which would never otherwise be possible. Or, to vary the metaphor, random mutation would never serve up anything other than a structureless hunk of marble were it not for natural selection chipping away everything that doesn’t look like David.

So Darwinism does not presuppose the arrival of the fit; it is a true theory of the origin — not just the survival — of species. It explains a great deal of the apparent design in nature. However, it does presuppose the existence of DNA or something like it — bodies capable of creating copies of themselves with not-quite-perfect fidelity. That alone implies a pretty impressive level of intelligible order, perhaps enough to motivate the ID hypothesis even without the help of eyes and hearts and brains and all the other things for which natural selection is an adequate explanation.

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Everything, including design, presupposes order.

Obviously the Darwinian theory itself cannot explain the origin of all the intelligible order in the universe, since it presupposes the existence of self-replicating structures.

Even more obviously, intelligent design cannot explain the origin of all the intelligible order in the universe, since it presupposes the existence of intelligent designers.

However, evolution and design do show us broadly what kinds of explanations of intelligible order are possible.

Watches, and the watchmakers who make them, show us that it is possible in principle for intelligible order to be the creation of an intelligent designer. Of course it’s not possible that life and the universe were designed by, say, George-Emile Eberhard — but perhaps by something like Eberhard, by some as-yet unknown intelligent agent.

Likewise, living organisms, and the Darwinian mechanism that makes them, show us that it is possible in principle for intelligible order to arise from a combination of random chance and blind regularity. Of course it’s not possible that life and the universe were created by natural selection as we know it — but perhaps by something like that, by some as-yet unknown unintelligent process.

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Unfortunately, neither evolution nor design can offer a real answer to the ultimate question of why there is order rather than no-order. This is probably just as unanswerable as Leibniz’s “Why is there something rather than nothing?” Any conceivable answer to Leibniz’s question would itself be a “something” in need of explanation — and in the same way, any conceivable explanation of the origin or order would imply a mechanism of cause-and-effect, and thus some underlying order.

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Design is an empirical question, not a philosophical deduction.

None of this means that there is anything illegitimate about the design hypothesis. Obviously, intelligent design is the correct explanation for the existence of a great many things — watches and computers and motorcycles and so on — and there’s no a priori reason why it couldn’t be the correct explanation for the existence of life or even of the entire known universe. Evolutionists who dismiss ID as unacceptable even in principle because it presupposes a creator and thus explains “exactly nothing” (Dawkins) are going much too far. Evolution may be more elegant and philosophically satisfying than ID because it explains more complex things in terms of simpler ones rather than vice versa, but none of that changes the fact that ID undeniably is the correct explanation for many things, and therefore cannot legitimately be ruled “meaningless” or “unscientific” or otherwise intellectually non-kosher.

However, creationists who assume that ID is the only possible explanation for complexity or intelligible order are also going too far. Design is a legitimate hypothesis — but that’s all it is. Like any other hypothesis, it must stand or fall on empirical grounds. “Order, therefore design” is not good enough because (1) design cannot logically be the source of all order, since it presupposes order; and (2) we have in Darwinian evolution an actual example of order arising without design, showing that this is possible in practice as well as in theory.

Proponents of ID often try to use Sherlock Holmes’ maxim from “The Adventure of the Blanched Soldier” — that once you have eliminated the impossible, whatever remains, however improbable, must be the truth — in an invalid manner. The argument goes something like this:

  1. X must have come into being either through intelligent design or through unintelligent processes (“chance”).
  2. No known unintelligent process can adequately explain X.
  3. Therefore, even in the absence of any positive evidence of design, we can conclude that X was designed.

This is invalid because there are actually four possibilities. X could be the work of (1) a known intelligent agent, such as Eberhard or some other human being; (2) an unknown intelligent agent, such as the “designer(s)” postulated by ID proponents; (3) a known unintelligent process, such as Darwinian evolution; or (4) an unknown unintelligent process. Of course no one takes the first possibility seriously where life or the universe is concerned; however, it’s hard to see why the fourth should be excluded from consideration. A more logically valid form of the above argument would be

  1. X must have come into being either through intelligent design or through unintelligent processes.
  2. No known agent or process — intelligent or unintelligent — can adequately explain X.
  3. Therefore, the cause of X is unknown and could be either intelligent or unintelligent in nature.
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Filed under Evolution, God, Philosophy

When did dogs figure out pointing?

In “Transposition,” a sermon delivered during World War II and published in 1949 in Transposition and Other Addresses, C. S. Lewis refers to dogs’ inability to understand pointing.

You will have noticed that dogs cannot understand pointing. You point to a bit of food on the floor; the dog, instead of looking at the floor, sniffs at your finger. A finger is a finger to him, and that is all.

If you’ve ever owned a dog, you will no doubt find this a rather extraordinary thing to say. Dogs obviously understand pointing, even without any training, and it’s quite common to train dogs to respond to pointing as a command (for example, pointing to a doorway to tell the dog to go into the room indicated). No dog I’ve ever met would waste time sniffing my finger when I’d just pointed out a bit of food it could eat. Cats, yes, but certainly not dogs.

However, Lewis had already had no fewer than six dogs by the time “Transposition” was published (details here), so it’s hard to dismiss what he says about them. This isn’t Pliny the Elder we’re dealing with, reporting hearsay about animals he’d had no personal contact with. Lewis knew dogs well and must surely have known from direct experience how they respond to pointing.

Is it possible that Lewis was right, and that dogs have changed in the half-century since he wrote?

We know that dogs’ ability to understand pointing is a relatively recent evolutionary development. According to dog expert Stanley Coren (as quoted in a 2009 Bloomberg article), domestic dogs understand pointing but their wild conspecifics do not.

“Suppose I point at something — the dog recognizes that I’m indicating something in that direction and looks,” Coren said, referring to a 2004 experiment carried out by Harvard anthropologist Brian Hare, which focused on the increase in dog IQ from domestication. “They do this even if they’re eight to ten weeks old, whereas a wolf, reared since puppyhood in a human environment, would look at my hand,” explained Coren.

Is it possible that the change Coren alludes to could have happened within living memory, sometime after the Second World War? It would be interesting to comb old books for references to dogs’ understanding or not understanding pointing and try to infer when the change took place.

I suppose it’s also possible that geography is a factor. Perhaps the North American dogs studied by Hare and Coren have abilities which English dogs do not. (Iain McGilchrist, a Scot, also refers to dogs’ ability to understand pointing, but he seems to be drawing on the same American research as Coren, not on his own experience.) Most of my own experience with dogs has been in America, but I often see stray Taiwan Tugous (a local breed far removed from anything in Europe or America) and should be able to test their responsiveness to pointing.

If you have any direct experience with dogs and pointing, or if you know of any references to it in books, please leave a comment.

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Filed under Dogs, Evolution

The New World is an older country

All the biggest land animals — elephants, rhinos, hippos, giraffes — live in Africa. Asia also has elephants and rhinos, but they are both smaller and less abundant than their African cousins, and no other continent is even a contender in terms of megafauna.

Even if we define megafauna more liberally and look only at abundant species, Africa still wins hands-down. I made a list of wild land mammal species which weigh 100 pounds or more and which are listed as “least concern” on the IUCN Red List. Even though many of Africa’s trademark megabeasts (elephants, rhinos, hippos, gorillas, and lions, among others) are excluded by the latter criterion, Africa still comes out on top. A full 50% of the species on the list (37 out of 74) live only in sub-Saharan Africa. By comparison, Eurasia (including North Africa) has 20 abundant megamammals, the Americas have 17, and Australia has 5. (The total is only 74 because 5 of the species are common to Eurasia and America.) The four heaviest species on the list (giraffe, Cape buffalo, and two species of eland) are all African. If I relaxed the conservation criteria a little, Africa’s dominance would be even more overwhelming.

Africa has not always been so exceptional, though. Until quite recently (geologically speaking), the other continents had significant megafauna of their own. North America in particular was home to several species of elephant, ground sloth, horse, and big cat. In his hunting memoir Green Hills of Africa, Hemingway comments on this and offers an explanation:

Looking at the way the [elephant] tracks graded down through the pleasant forest I thought that we had the mammoths too, a long time ago, and when they travelled through the hills in southern Illinois they made these same tracks. It was just that we were an older country in America and the biggest game was gone.

Hemingway surprises us a little here, turning our familiar ideas upside down and calling the New World “an older country.” What he presumably means is that humans have been hunting there for a longer time than in Africa and have killed off most of the big game — which is the exact opposite of the truth. Our species evolved in Africa, and the Americas were the very last continents we colonized. So why, if Africa has been subject to human hunting for so much longer than America, does America seem to be “hunted out” while Africa still abounds in big game? Later in Green Hills Hemingway writes:

A continent ages quickly once we come. The natives live in harmony with it. But the foreigner destroys . . . . Our people went to America because that was the place to go then. It had been a good country and we had made a bloody mess of it and I would go, now, somewhere else and as we had always gone. You could always come back. Let the others come to America who did not know that they had come too late. Our people had seen it at its best and fought for it when it was well worth fighting for. Now I would go somewhere else. We always went in the old days and there were still good places to go.

Nothing surprising here, at least at first glance. “The natives live in harmony with it. But the foreigner destroys” sounds like the familiar cliché about how every country was an ecological paradise until the white man showed up and ruined everything — a cliché to which there is admittedly some truth, since whites did in fact decimate the megafauna of both America and Africa. Whites couldn’t have killed off America’s mammoths, though, or her ground sloths and horses and the other Pleistocene megafauna, all of which went extinct millennia before Columbus sailed the ocean blue. If humans are to blame for those extinctions (and circumstantial evidence certainly points to us), the culprits were the Clovis people — Paleo-Indians, the ancestors of “the natives.” They were still “foreigners” when they killed off the mammoths, though, having recently arrived from Siberia. When “natives” and “foreigners” are understood in a general sense, rather than as referring to specific ethnic groups, Hemingway’s point makes sense and is consistent with his earlier reference to America as “an older country” — that is, a country with a longer history of depredation by foreigners — than Africa.

In the big picture, Africa is the only land that can properly be said to have natives, the only place on earth where humans are not an invasive species. Humans and the African megafauna evolved in tandem, adapting to each other; the game animals evolved the instincts they needed to survive in an environment which included human predation, and the humans developed sustainable hunting practices.

In America, on the other hand, the Clovis suddenly showed up in a land whose wildlife had no evolutionary history of living with humans, and the results were disastrous. Over time, the Paleo-Indians learned to live in harmony with their new habitat and became naturalized “natives,” and the surviving megafauna presumably evolved as well, developing an instinctive fear of humans and other adaptations which would help them survive in the new (humanized) America. Millennia later, when the next wave of “foreigners” arrived in the New World, there was to some extent a repeat of the Clovis apocalypse, but on a much smaller scale. After all, the animals had already adapted to living under human predation in a general sense and only had to deal with the somewhat different behavior and technology of the Europeans. Though the Europeans greatly reduced the numbers of several species (bison, wolves, etc.), there were few all-out extinctions. In comparison to the totally foreign Clovis invaders, the Europeans were only somewhat foreign and therefore easier to adapt to — like adapting to a new strain of flu, as opposed to a completely novel pathogen.

It would be hard to overstate the difference between Africa and America in terms of big game. America (North and South) is over twice as large as Sub-Saharan Africa in terms of land area; it includes a wider variety of climates, which should be conducive to the evolution of more species, and it includes the colder climates which Africa lacks and which (based on Bergmann’s rule) should tend to produce physically larger species — and yet Africa has over twice as many abundant species of large mammal as America. Perhaps the reason lies in the fact that Africa, alone among continents, has never been invaded by a truly foreign human population like the Clovis in America, only by foreign strains of a locally evolved species.

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Filed under Animals, Evolution

Nietzsche, Darwin, and man’s Sonderstellung

The following passages are from Walter Kaufmann’s Nietzsche (4th ed.), but they neatly summarize some very common (and, I think, wrong) ideas about the worth of man and the ramifications of evolution. I often encounter similar thinking from people whose thought is otherwise very far from Nietzsche’s.

If the teaching of evolution is correct and man is not essentially different from the apes; if he is, as all appearances seem to indicate, more similar to the monkeys than these are to the “lower” animals; if he is just another of the primates; then it would follow, Nietzsche thinks, that the mass of mankind lack any essential dignity or worth.

No quantitative addition, either of more and more human beings or of more and more intelligence (which man is supposed to share with the chimpanzee, though he has more of it), can give man the unique dignity which the Western tradition has generally conceded him. What is worthless to start with, cannot acquire value by multiplication. [p. 150]

Nietzsche agrees with the Christian tradition and such thinkers as Kant and Hegel that the worth of man must consist in a feature he does not share with any other animal. He believes that the worth of man , and thus the value of his life, his creations, and his acts, depends on his Sonderstellung, his unique position, in the cosmos. Darwinism, however, instead of infusing him with optimism, convinces him that empirical facts do not bear out the prevalent view that all men, as such, occupy a unique position in the cosmos. [pp. 151-152]

He accepted Darwin’s doctrine concerning the lack of any cardinal distinction between man and animals as incontrovertible empirical fact and tried to counter this “deadly” gospel with the new, Nietzschean, assertion that man can rise above the beasts. He granted that the factor of intelligence does not distinguish man from all other animals and that most men’s behavior is not essentially different from animal behavior — notions which are basic in much recent psychology. Our skills, crafts, and techniques can only raise us to the level of super-chimpanzees. Nietzsche, however, defied Darwin, as it were, to find even traces of art — which he distinguished from the crafts — or of religion or philosophy among the animals. If a technician is only a super-ape, the same cannot be said of Plato. Some pursuits are supra-animalic, and the man who engages in them is a truly human being and has unique worth. The artist, saint, and philosopher are representatives of true humanity and culture. [p. 175]

This line of reasoning goes wrong from the very beginning, when it assumes that the theory of evolution implies some special similarity between man and the apes — a similarity which we would not have to accept if evolution were not true. Actually, Linnaeus had already classified man as “just another primate” over a century before the Origin of Species. Man’s similarity to the apes is not a conclusion which follows from Darwinism, but rather one of the observable facts for which Darwinism offers an explanation. The striking similarities — and equally striking differences — between man and chimp remain what they have always been: empirical questions of comparative anatomy and psychology, to which the answers are no different after Darwin than they had been before. Disraeli, mistaking an explicandum of a theory for the conclusion of an argument (an error we will revisit below), thought that Darwinism posed the question, “Is man an ape or an angel?” and that creationists were on the side of the angels — but man remains what he is, ape-like in some ways, angelic in others, regardless of what theory we put forth to explain how he got to be that way.

There is a tendency (a fallacious one) to assume that two things which came into being by the same kind of process must therefore have the same basic nature — as Isaiah implies in his mocking description of a carpenter who cuts down a tree, burns some of the wood to cook his dinner, and then makes himself a “god” from the remainder. How absurd to think that the same sort of creative process could yield both firewood and a god! Yet one finds a ready parallel in the opening chapters of Genesis, where a single Creator uses the same raw material (dirt) to create cattle, creeping things, and a man in his own image. In a way Genesis even seems to anticipate Linnaeus, portraying the division between man and beast as less fundamental than that between fish and fowl on the one hand and land animals (including man) on the other. Darwinism doesn’t really change the fundamental picture of man — the highest of animals, but an animal nonetheless — as much as we sometimes like to think it does.

At any rate, it is a fact — irrespective of the truth of Darwin’s theory — that man is one animal species among others and that most of the faculties we think of as distinctly human can also be found, in less developed form, in other species — particularly in our closest relatives, the great apes. For Nietzsche (as interpreted by Kaufmann, anyway; assume this disclaimer throughout), it follows that those faculties — including, most importantly, intelligence — have no value, since “what is worthless to start with, cannot acquire value by multiplication.” But this only makes sense if we start with the assumption that the intelligence of lower animals is literally worthless — not just of little or even negligible value (since small numbers can acquire value by multiplication), but of no value whatsoever. It may be that some people hold this opinion, considering the mind of a dog or horse to be of no more worth than an insensate chunk of stone, but it is, to put it mildly, not exactly self-evident.

A deeper problem with this line of reasoning is its sloppy reification of intelligence, which is treated as a sort of homogeneous stuff which can be increased by “quantitative addition.” To say that the key difference between Descartes’s mind and that of a Jack Russell terrier is that one has a greater quantity of something than the other, is shallow to the point of meaninglessness. “Intelligence” is a high-order abstraction concealing fundamental qualitative differences in the ways different minds are structured and in the kinds of cognitive tasks they are able to perform. At a sufficiently high level of abstraction — employing terms like “intelligence,” “complexity,” “value” — virtually any difference can be made to seem merely quantitative. And underlying the whole issue is the unspoken assumption that “merely” quantitative differences are unimportant and really hardly qualify as differences at all — that if man differs from a chimp only quantitatively, then man essentially is a chimp. In fact, the distinction between quantitative differences (which include, let us not forget, the difference between day and night) and qualitative ones is itself quantitative, as should be clear to anyone who is familiar with the periodic table or who has observed that oceans tend to behave rather differently from drops of water.

Nietzsche’s list of what is unique to man — art, religion, and philosophy (but not intelligence or technology) — is arbitrary, an artifact of a decision to classify human activities at one particular level of abstraction rather than another. Kaufmann feels the need for a parenthesis explaining that Nietzsche distinguished the arts from the crafts, an implicit admission that such a distinction is not objectively obvious or inevitable, that others may see a “quantitative” continuum where Nietzsche saw a bright line. Similarly, philosophy could easily be seen as a special case or particularly advanced form of the kind of thinking or reasoning of which many other animals are capable. Even religion seems less qualitatively unique when we consider that other animals are certainly capable of superstition, selfless devotion, and so on.

Every action, considered in its totality, is unique. It can be considered non-unique only if some of the details are abstracted away and it is viewed as a member of a category. Since infinitely many levels of abstractions are possible, and since at a high enough level of abstraction nothing is unique, any binary classification of human activities as “unique” or “not unique” will be arbitrary. Considered in its totality, Titian’s Assumption of the Virgin is unique. Considered more abstractly as an example of representational art, it belongs to a category which includes such non-human productions as Stink Gorilla More. Classed broadly as an artifact, it is not even uniquely mammalian.

But the irrelevance of this whole line of thinking is beginning to become all too obvious. Are we really supposed to believe that the existence of a still life painted by a gorilla has any bearing on the value of the art of Titian? As I wrote in my post on Aristotle, absurd conclusions follow from the assumption (the amazingly common assumption!) that whatever is unique to man is more valuable than what is not. Nietzsche denigrates technology as the domain of mere “super-chimpanzees” — but if we exterminated all the chimps and crows and other tool-making species, or if those species had never evolved in the first place, would the technician then take his place with the artist, saint, and philosopher as a model of true humanitas? To spell the reductio out: Is the existence of chimpanzees the only thing that prevents us from considering Edison the equal of Plato?

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If the insistence on human uniqueness — Sonderstellung — is so obviously absurd, though, why have so many first-class thinkers (Kaufmann mentions Kant, Hegel, and the Christian tradition, and of course there is also Aristotle) taken it for granted? A full answer to that question would require a deeper familiarity with each of those individual thinkers than I can pretend to — but, in broad terms, I can imagine two different ways such an idea could come about.

First, there is Disraeli’s error, that of taking an explanation for an argument and an explicandum for a conclusion. (The ambiguity of the word “therefore” is evidence of how naturally this particular error comes to us.) Philosophers may have begun by assuming that man’s life has far more value and meaning than a beast’s, and the search for an explanation of that unique value — where it comes from and in what it consists — would naturally have led them to the question of which of man’s traits are unique to man — just as someone seeking to understand, say, why the Industrial Revolution began when and where it did, would naturally begin by considering what was distinctive about 18th-century England. Of course, if nothing specially (or “qualitatively”) distinctive were found, no historian would conclude that therefore the Industrial Revolution didn’t happen in England! — but somewhere along the line, the philosophers may have made a corresponding error. Nietzsche, at any rate, certainly seems to have done so. Having already fallen for Disraeli’s error in the original sense, as it applies to evolution, it is perhaps no surprise that when it comes to the question of man’s Sonderstellung, he goes on to make the same mistake.

Second, there is a sense in which purpose and value really do presuppose uniqueness: Anything which does not perform a unique function is dispensable. If anything X can do, Y can also do — if, that is, every purpose which X serves could be served just as well even if X didn’t exist — then doesn’t it follow that X has no value and no reason for existing? Well . . . an affirmative answer is possible, but it requires so many qualifications and asterisks that one should be very careful about treating it as a generally valid law and applying to recklessly to any situation that comes along. Here are a few of the many caveats to keep in mind:

  • Even the tiniest “quantitative” differences can still be relevant. Precious little distinguishes an HB pencil from an F pencil, for example, or an AA battery from a triple-A  (to say nothing of Thomas Edison and a chimpanzee!), but the two are still not always interchangeable.
  • A non-unique thing can be an essential part of a larger system. For example, neither my left eye nor my right eye is unique, but together they perform a function (binocular vision) which neither could do alone.
  • A non-unique thing can add value in a simple quantitative way. The more bricks you have, the more things you can build.
  • Two things with precisely the same range of  potential functions can still distinguish themselves by performing different actual functions. The fact that I could do any number of different jobs doesn’t make the people who actually do those jobs redundant.
  • Even something which is redundant in every possible way can still have potential value and therefore purpose. The world changes, and what is redundant and useless now may become unique and indispensable in the future. Backup CDs, for example, are created with such contingencies in mind.
  • A corresponding function shouldn’t be mistaken for a redundant one. My eyes don’t make your eyes redundant.

But perhaps the biggest thing to keep in mind is that uniqueness is a property of individuals. Unique means unique, not shared with six billion other people. The concept that “all men, as such [emphasis added!], occupy a unique position in the cosmos” — well, it sounds like something out of Life of Brian. Either uniqueness is important or it is not; the emphasis so many philosophers place on what is “unique to man as such” — that is, that which is common to all the billions of human beings in the world but (and this is deemed important!) not shared by a few thousand chimps — seems completely arbitrary.

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Filed under Evolution, Philosophy

Shaw and Darwin

Bernard Shaw’s preface to Back to Methuselah, “The Infidel Half Century,” is something you don’t see much of these days: a non-creationist attack on Neo-Darwinism.

Back to Methuselah was published in 1921, a good 15 years before the modern synthesis got underway, so “Neo-Darwinism” as Shaw uses the term means something different: not Darwin-plus-Mendel, but Darwin-minus-Lamarck. Unlike Darwin himself, who was willing to grant that Lamarckian processes (the inheritance of acquired characteristics) might play some role, the Neo-Darwinians broke with Lamarck completely and insisted that evolution was driven almost exclusively by what Shaw — not wishing to profane the name of Nature — insists on calling Circumstantial Selection.

It’s not that Shaw doesn’t believe in natural selection — he grants that it occurs and that it influences evolution — but he considers it to be an incidental process. He thinks of natural selection the way a more orthodox evolutionist thinks of genetic drift: It undeniably happens, but it’s not all that important and evolution could go on just fine without it. The real driving force behind evolution is voluntary change.

If you can turn a pedestrian into a cyclist, and a cyclist into a pianist or violinist, without the intervention of Circumstantial [that is, natural] Selection, you can turn an amoeba into a man, or a man into a superman, without it. All of which is rank heresy to the Neo-Darwinian, who imagines that if you stop Circumstantial Selection, you not only stop development but inaugurate a rapid and disastrous degeneration.

Let us fix the Lamarckian evolutionary process well in our minds. You are alive; and you want to be more alive. You want an extension of consciousness and of power. You want, consequently, additional organs, or additional uses of your existing organs: that is, additional habits. You get them because you want them badly enough to keep trying for them until they come. Nobody knows how: nobody knows why: all we know is that the thing actually takes place.

The details of this process are admittedly a little sketchy, even if we take the heritability of acquired characteristics for granted. It’s easy enough to imagine how a giraffe — the canonical example, which Shaw dutifully trots out (“I do not remember how this animal imposed himself illustratively on the Evolution controversy; but there was no getting away from him then; and I am old-fashioned enough to be unable to get away from him now.”) — might want a longer neck, try to get one by stretching, and succeed in lengthening its neck a bit. But when one tries to picture a cartilaginous fish “trying” to have bones, or a monkey “trying” not to have a tail (not to mention a plant or an amoeba “wanting” or “trying” to do anything at all), the theory seems to break down.

For Shaw, the important thing about Lamarckism is not the inheritance of acquired characteristics, but the importance of will in the evolutionary process. In fact, Shaw seems to think that the former depends on the latter — that acquirements are inherited if and only if they were acquired deliberately rather than by accident. (He expresses this in a rather confusing way, saying that only “habits” can be inherited, but makes it clear that he is using “habit” in a special sense which includes not only customary behavior patterns but anatomical features as well. A Shavian “habit” is any feature that is voluntarily acquired and thereafter becomes involuntary and automatic.)

Because of Shaw’s focus on the inheritance of voluntarily acquired characteristics, he dismisses the experiments of August Weismann — in which he cut off the tails of 20 successive generations of rats and observed that their offspring were nevertheless born with tails — as missing the point. Shaw considers it self-evidently ridiculous to suppose “that injuries or accidents coming from external sources against the will of the victim could possibly establish a [heritable] habit: that, for instance, a family could acquire a habit of being killed in railway accidents.” He proposes the following as an alternative experiment which, if it were practicable, would be more relevant to the Lamarckian hypothesis as he understands it.

The scientific form of his experiment would have been something like this. First, he should have procured a colony of mice highly susceptible to hypnotic suggestion. He should then have hypnotized them into an urgent conviction that the fate of the musque [sic] world depended on the disappearance of its tail, just as some ancient and forgotten experimenter seems to have convinced the cats of the Isle of Man. Having thus made the mice desire to lose their tails with a life-or-death intensity, he would very soon have seen a few mice born with little or no tail. These would be recognized by the other mice as superior beings, and privileged in the division of food and in sexual selection. Ultimately the tailed mice would be put to death as monsters by their fellows, and the miracle of the tailless mouse completely achieved.

The objection to this experiment is not that it seems too funny to be taken seriously, and is not cruel enough to overawe the mob, but simply that it is impossible because the human experimenter cannot get at the mouse’s mind.

The odd thing about this — okay, there are a lot of odd things about it, but one of the odd things about it — is how thoroughly Darwinian it is. A true Lamarckian would perhaps expect that, once the mice had been suitably hypnotized, they would somehow try very hard to reduce the length of their own tails and would succeed in doing so, if perhaps only to a very slight degree. (Exactly how this would be done is, as I have said, not so clear.) Their children would then be born with very slightly shorter tails, which they in their turn would shorten a bit by the same method, and after many repetitions of this process a generation of tailless mice would finally be produced.

Shaw predicts something completely different. Instead of the mice changing their own bodies by willpower and then passing on those changes to their children, he imagines that the mice’s desire for taillessness would somehow cause a few tailless mutants to appear a generation or two later, and that the tailless mutation would become the norm by means of a process which can only be described as eugenics — that is, self-imposed artificial selection, which is nothing more than a special case of Darwinian natural selection. The bit about the mutation arising “very soon” as a result of the mice’s desire (rather than arising eventually by chance) is the only hint of anything non-Darwinian in Shaw’s story.

Unlike the mouse story in the preface, which is not Lamarckian at all, the Back to Methuselah plays themselves do feature the inheritance of acquired characteristics. In the story, a few people read a book arguing that the human lifespan must be extended to at least 300 years, and as a result they themselves — not the next generation, as in the case of the mice — go on to live for 300 years! Somehow their desire directly causes sweeping physiological changes, which are then inherited by their children. The implication is that, had they instead read a book arguing that humans all ought to be nine feet tall, they could simply have taken thought and added the requisite cubits to their stature. (The physiological changes implied in increased longevity are internal and invisible, which helps make the story seem a little less obviously ridiculous. That’s probably why the mouse story, featuring a more obvious physical feature, used a different mechanism. It would be too clearly bogus if the mice’s own tails had simply disappeared after the hypnosis.) After that, eugenics — in the form of sexual selection and genocide — once again takes over. The long-lived people seek each other out as mates “for the good of the race,” and eventually they decide to kill off all the short-lived ones. No matter how hard he tries to be a good Lamarckian, Shaw’s imagination keeps being drawn back to Darwinian mechanisms.

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The Argument from Desire

I’ve recently read two discussions — one by philologist Edward M. Cook (of Ralph the Sacred River), and one by Christian apologist Peter Kreeft — of what is being called the Argument from Desire. Then, by a strange coincidence, John C. Wright also came out with a post about it while I was in the process of composing this one.

The argument, though not the name, comes from C. S. Lewis, who summarizes it as follows in the tenth chapter of Mere Christianity:

Creatures are not born with desires unless satisfaction for these desires exists. A baby feels hunger; well, there is such a thing as food. A duckling wants to swim; well, there is such a thing as water. Men feel sexual desire; well, there is such a thing as sex. If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world.

This is not strictly speaking an argument for the existence of God, but for an undefined something which is beyond all known human experience. As Kreeft puts it, “What it proves is an unknown X, but an unknown whose direction, so to speak, is known. This X is more: more beauty, more desirability, more awesomeness, more joy.” Still, if even this much can be proved — if we have reason to believe in something beyond this world which is nevertheless intimately connected with human desires and interests — it gives us at least a starting point from which to theologize.

Of course no one would argue that every human desire — including my desire for an ansible and a cloak of invisibility — implies the existence of an object that would satisfy it, only that we are not born with vain desires. Lewis’s argument only applies to natural, innate, instinctive desires, so the first question that arises is how to distinguish these from artificial ones. Kreeft proposes the following criteria:

  1. We generally “recognize corresponding states of deprivation” for natural desires, but not for artificial ones. “There is no word like ‘Ozlessness’ parallel to ‘sleeplessness.'”
  2. Because natural desires come from our shared human nature, they “are found in all of us, but the artificial ones vary from person to person.”

Kreeft’s first point seems not to favor Lewis, who was so far from seeing his unsatisfied desire as a state of deprivation analogous to sleeplessness that he actually dubbed it “Joy” — not the desire for Joy, mind you, but Joy itself. As far as Lewis was concerned, his desire was not for Joy; it was Joy. The desire was itself intensely desirable. In that respect it seems more like an artificial, fanciful desire than a natural, biological one. Are intense hunger, loneliness, sleep deprivation, and so on ever joyous experiences? Wouldn’t it be odd if they were? Fantasizing about the land of Oz, on the other hand, can be rather pleasant.

The second point is also problematic, since so many obviously fanciful desires are nevertheless near-universal. As Wright (who, despite his Lewisian sympathies, finds this particular argument weak) puts it, “Who has not longed to fly to the stars . . . to speak to the trees and rivers and hills, . . . or peer into the thoughts of another, or live his life?” And who has not felt Lewisian Joy, the “desire which no experience in this world can satisfy,” a persistent longing which is no less intense for being vague? All of these must be in some sense “natural,” since they come so naturally to us, but it hardly follows that there must exist something which can satisfy them.

Desires, after all, do not exist to be satisfied; they exist to motivate behavior. Often the behavior elicited by a desire will result in its satisfaction (e.g., hunger motivates eating, and eating satisfies hunger) but this need not always be the case. Take for example the proverbial method of motivating a donkey to move by dangling a carrot in front of it, where the donkey’s desire serves its purpose (making the donkey move) even if it is never satisfied. In fact, the minute you actually let the donkey eat the carrot, it will stop walking and the purpose of the desire will be frustrated. You should only let it eat the carrot after you have reached your destination and no longer want the donkey to move; if you want it to keep moving indefinitely, you should never let it eat the carrot. Creating a desire serves to make the donkey move; satisfying the desire serves to make it stop. (Of course this is a highly artificial example, but in principle there’s nothing to stop nature from doing something similar.) So in thinking about desire and satisfaction, we need to keep in mind two important points — important enough to be bulleted:

  • To understand why a given natural desire exists, the correct question to ask is not what would satisfy it, but what evolutionarily useful behavior it serves to motivate.
  • Other things being equal, we should expect a desire to be satisfied only when, and only for so long as, the behavior it serves to motivate is no longer useful.

If there were some behavior which it were evolutionarily beneficial for us to perform only once, or only a specific finite number of times, then we could expect to find a natural desire which could be satisfied in the fullest sense of that word — we reach the intended goal, the desire is completely and permanently quenched, and we move on to other things. Mission accomplished. It’s hard to think of any clear examples of this in the real world, though, which is perhaps only to be expected. The evolutionary project — ensuring that copies of as many of our genes as possible continue to exist for as long as possible — is inherently open-ended, a race with no finish line, and we might expect a similar open-endedness in the desires which were created to serve it.

More typically we find that our natural desires can be satisfied, but only for a time. The satisfaction is temporary, and the desire is quenched and rekindled, quenched and rekindled, in a cycle that can continue indefinitely. We eat, we drink, we sleep — but hunger, thirst, and fatigue are never banished for long. All the rivers run into the sea, yet the sea is not full. This is a confusing state of affairs if we see satisfaction as being the purpose of desire, but it makes perfect sense if we keep in mind that desires exist to trigger behavior and satisfaction exists to turn it off. When the body needs fuel, the desire to eat is turned on; when it has enough, and eating more would actually be detrimental, the desire is turned off — satisfied — but only until fuel supplies begin to run low again.

The on-again off-again nature of hunger is explained by the fact that eating regularly is evolutionarily useful but eating until you burst is not. But what if there were a behavior which, unlike eating, was always useful and never needed to be turned off? Well, in that case we would expect that behavior to be motivated by a desire which could never be satisfied. The most obvious example of this in nature is our desire for life itself. Nature has given most of us an insatiable desire to go on living indefinitely, not because immortality is actually on offer, but to motivate us to extend our finite lives for as long as we possibly can. Other ways of coping with our unacceptable mortality — having children, trying to bequeath something of lasting value to posterity, and so on — also tend to serve evolution’s ends. So long as we keep chasing the carrot of eternal life, pulling our wagonload of selfish genes behind us, the desire serves its purpose, even if satisfaction remains forever out of reach.

Lewisian Joy isn’t as straightforward as a desire for immortality — it’s a vague desire for a certain je ne sais quoi — and so the behavior it serves to motivate is less easily characterized. However, I suspect that it still does serve to motivate broadly predictable patterns of behavior. Someone who is motivated by Joy is likely to seek, as Kreeft puts it, “more awesomeness” — where our idea of awesomeness will tend to be drawn from our other, more straightforward (and more clearly evolutionarily useful) desires. The inchoate longing for “something more” is not as open-ended as it might seem, since our human nature will predictably direct it towards certain goals (such as power, wisdom, and beauty) rather than others (such as trying to ensure that the number of turnips in the world is prime). Given how clever our species is, and how good we are at finding ways to cheat evolution by satisfying our desires without reaching the goals for which those desires were created (see my post on the Genie scenario) — Joy may be a broadly effective way of keeping us from resting on unearned laurels.

I’m getting into just-so-story territory here, but all that’s really necessary to counter Lewis is to come up with an explanation for vague unsatisfiable desires which, however hypothetical and ad hoc it might be, is at least less far-fetched than his own “most probable explanation” — namely, that there must exist some “other world” than the known universe and that it was for this hypothetical world that we were “made.” And, that, I think, is a pretty easy standard to meet.

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Reading: Charles Darwin

  • The Origin of Species by Means of Natural Selection, edited with an introduction by J. W. Burrow (25 Jun 2009)

My family read this together when I was a kid and we were all creationists, and the only thing that stuck with me was the comical image of a bear swimming around with its mouth open catching insects. At that time I took the truth of Mormonism (as interpreted by my father, for whom creationism is something of a hobby) for granted and didn’t really give it a fair hearing. Actually, I didn’t give it any kind of hearing in the sense of engaging its ideas at any deeper level than, “Well, we all know that’s wrong.” I was unsympathetic without managing to be actually critical.

I’ve since come back to Darwin’s theory and found it compelling, but until now I had approached it only through modern popularizations, especially those of Richard Dawkins (an author who was recommended to me by my father, of all people). This is my first time rereading Darwin himself. Here are a few brief thoughts:

  • Darwin’s not a bad prose stylist. He overuses a few phrases (a lot of “light” is “thrown” on a lot of things by Darwin’s theory, and he always tells us so in those particular words), and the sometimes archaic technical terms call for frequent use of the glossary (apparently amphibians used to be called “batrachians”; who knew?), but overall the writing is clear and even elegant.
  • Given the way histories of evolution tend to focus on the contrast between the two men’s theories, Darwin turns out to have been much more of a Lamarckian than I would have expected. Many times throughout the book he grants the possibility of acquired characteristics being directly inherited, or learned behaviors being passed down as instincts. Of course he had the considerable handicap of not knowing anything at all about genes. Knowing about genes changes everything.
  • I like Darwin’s empirical spirit. Rather than just speculating, for example, that seeds might have been carried across the sea by birds, he carried out experiments to test the ability of various seeds to germinate after being immersed in salt water, ingested by a heron, etc. He didn’t take anything for granted. He also came up with some clever ways to test his theory which I wouldn’t have thought of myself, such as seeing whether species belonging to larger genera are more variable than those from smaller ones. This attention to detail and knack for making things testable — not the general idea of evolution by natural selection — is what set Darwin apart from all the evolutionary conjecturists who preceded him.
  • It’s true about the barnacles! They turn up again and again, though usually in disguise as “sessile cirripedes.” He knew an awful lot about the little beasties.

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