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November 30th, 2012 (Permalink)

Blurb Watch: Hitchcock

November 29th, 2012 (Permalink)

Headlines

Rice a bust with Republican senators

Obama Calls Rice ‘Extraordinary,’ as Another Republican Voices Concerns

November 28th, 2012 (Permalink)

Check it Out

Epidemiologist Geoffrey Kabat, author of Hyping Health Risks, has a Slate article on the dangers of dietary supplements:

Though we tend to equate natural with healthy, plants have developed toxins to protect themselves against predators. The perception that herbal supplements and botanicals are inherently safe is belied by extensive evidence of the danger posed by such products….

Source: Geoffrey Kabat, "Natural Does Not Mean Safe", Slate, 11/26/2012

Fallacy: Appeal to Nature

November 22nd, 2012 (Permalink)

Giving Thanks

Thanks to everyone who has supported The Fallacy Files since last I thanked you! By visiting advertisers, making purchases through Amazon, or donating via PayPal, you've helped to keep the site going over the last year.

Resource: How to Support The Fallacy Files

November 17th, 2012 (Permalink)

New Book: Darwin

The historian Paul Johnson's latest book, a short biography of Charles Darwin, was reviewed recently by Mark Joseph Stern in Slate. I haven't read Johnson's book, so I'm relying here on the review. If Stern misrepresents the book, then he attacked a straw man. I'll deal with the arguments that Stern attributes to Johnson, and not with the accuracy of Stern's interpretation, which I'm in no position to judge. Even if Johnson didn't make these arguments, others have. There are two arguments that Stern attributes to Johnson, both forms of the appeal to consequences:

1. There is harm…―intellectual harm, historical harm, and moral harm―in attributing to Darwin a startling majority of the 20th century’s tragedies. This is what Johnson attempts to do in the later pages of his book. We are informed that Darwin’s theory led directly to the development of eugenics and forced sterilization, and that the United States’ pre-World War II anti-immigrant policies “can be traced back to the publication of [The] Origin [of Species].” Even more sinisterly, Darwin’s book was allegedly relied upon by the Nazis in developing their racial theories, and Marx cited it in support of communism. “Both Himmler, head of the SS and Goebbels, the propaganda chief,” were students of Darwin, Johnson ominously reminds us, and Hitler apparently carried the theory of natural selection “to its logical conclusion.” “Leading Communists,” moreover, “from Lenin to Trotsky to Stalin and Mao Tse-tung” considered evolution “essential to the self-respect of Communists." … Even Stalin―not a learned man by any stretch―“had Darwin’s ‘struggle’ and ‘survival of the fittest’ in mind” when murdering entire ethnic groups, as did Pol Pot, by Johnson’s telling. … And so on. You get the idea: Johnson marches again and again up to the line of actually blaming Darwin for millions of deaths, relying on guilt by association to make his point. It’s a dirty game, and a dangerous one, for character assassination can be a much more effective way of rejecting natural selection than is flat-out denial.

   This is an appeal to social consequences, that is, it's the argument that Darwinism, or belief in evolution in general, has led to bad social consequences, such as racism or eugenics. Proponents may be reluctant to come right out and declare that Darwin or the theory of evolution is wrong for this reason, but even if they don't explicitly draw that conclusion, it's a logical boobytrap. For instance, some people may be frightened away by such accusations from even examining the evidence for the theory.

   Also, as Stern suggests, there is guilt by association lurking in the linking of evolution to Hitler and Stalin: if these bad guys believed in it, it must be bad in some way. Again, people who argue this way sometimes don't come right out and say that evolution must not have happened because bad people believe it, but even if they don't they're still setting a boobytrap for the unwary.

   One reason why those who make these kinds of argument may shy away from their conclusions is that they're so obviously invalid: whatever good or bad consequences there are of believing something have no bearing on whether it's true or false. For instance, it may be true, as is widely believed, that children who believe in Santa Claus are happier and better behaved than those who don't. Similarly, Hitler was an early opponent of cigarette smoking.

2. Johnson spends the last pages of the book discussing Darwin’s supposedly cranky old age―according to the author, Darwin entirely lost his taste for the arts and human interaction―and, with breathtakingly little evidence, blames it on the scientist’s own theory. Natural selection, Johnson writes, caused Darwin to “close his mind to speculation about the infinite,” to reject God, to see human development as a constant cycle of cruelty.

   This is an appeal to personal consequences, that is, the alleged effects on one's personal life of believing the theory of evolution by natural selection, and Stern suggests one thing that's wrong with it:

   (It apparently did not occur to Johnson that many old people are sickly or pessimistic, even those who didn’t develop a comprehensive theory of evolution.) … Many nonreligious people recognize the truth of natural selection without collapsing into nihilistic despair; one need not reject the reality of evolution in order to live a meaningful, moral life. To suggest otherwise, as Johnson does, is an insulting and illogical demand that we must either abandon science for blind belief or else face a lifetime of anguish. Johnson’s book does readers a great disservice, masquerading as an objective biography before descending into mud-slinging nonsense. …

   However, even if Darwin's theory of evolution by natural selection is a less rosy picture than a religious story of origins, and may lead someone to live a less happy life than they might otherwise, that has absolutely nothing to do with which is true. There's no reason why the universe has to be set up to make us happy, and to think otherwise is to engage in wishful thinking.

Whether Johnson himself makes these arguments or not, they are familiar ones from the creationist literature―I'm not sure whether they carry over to the "intelligent design" movement. Such arguments tend to be made by religious believers who may be used to arguing for their beliefs on the basis of their alleged good social and personal effects. Perhaps in the case of religion these are reasonable ways of arguing―maybe even they're the only way―but they have no place in science.

A non-logical point concerns the history of science: According to Stern, Johnson tries to blame Darwin for communism in general and Stalinism in particular. However, Stalin explicitly rejected Darwinism for Lysenkoism, a form of Lamarckism. Lamarck's was a pre-Darwin theory of evolution based on the inheritance of acquired characteristics as the mechanism of evolution, rather than natural selection. In other words, if anybody is to blame for Stalinism―other than Stalin, that is―it's Lamarck, not Darwin. As a result, in the Soviet Union under Stalin, Darwinism was considered a form of bourgeois science, and some biologists were sent to the Gulag for advocating it, whereas Lysenkoism was proletarian science. This politicization of science set Russian biology back decades, and I don't know whether it's caught up with the rest of the world even yet.

So, the appeal to social consequences is not only a logically fallacious argument, but the premiss in the case of Stalinist Russia is false, so that this argument is unsound in two ways: it's both invalid and has a false premiss. Something similar can be said about Nazism, and other racist theories: to whatever extent they invoked evolution in general, or Darwin in particular, as justification, it was based on a misunderstanding or misrepresentation of the science.

Thus, if Stern is right, it appears that Johnson can't even get the history of the theory of evolution right. There are already many biographies of Darwin available, including quite recent ones. Stern mentions the need for a short one, as opposed to the weighty, thousand-page tomes that recent biographers have produced. However, there's already Tim M. Berra's Charles Darwin: The Concise Story of an Extraordinary Man, which is from only a few years ago and appears to have been well-reviewed. If you must read a short biography of Darwin, this looks like a better bet.

Sources:

• Martin Gardner, Fads and Fallacies in the Name of Science (1957), Chapter 12
• Mark Joseph Stern, "Darwin, That Genius, Was Responsible for Hitler, Stalin, and Pol Pot", Slate, 10/11/2012

Fallacies:

• Appeal to Consequences
• Guilt by Association
• Wishful Thinking

Update (11/23/2012): I've now read Johnson's book, and Stern is guilty of assault and battery on a straw man, as Johnson doesn't make the kind of fallacious arguments that I criticized above. In the penultimate chapter of the book, Johnson engages in a standard criticism of social Darwinism, which plausibly had an influence on Nazism, if not communism. In doing so, he makes it reasonably clear―though, perhaps, he could've been even clearer―that social Darwinism is not the same thing as the theory of evolution or of natural selection. Johnson writes:

[Darwin] was…perturbed by the ever wider and adventurous use thinkers at home and abroad were making of his work on evolution, for political, economic, and ideological purposes. He found himself under the lengthening shadow of social Darwinism. … Herbert Spencer…who had got on to "the survival of the fittest" even before Darwin, received a dynamic boost from the universal success of Origin …. Spencer enlarged the debate…the struggle to survive applied not just to individuals but to entire societies and nations. (pp. 125-126)

Johnson is critical of Darwin for ambivalence about such social applications of natural selection, but Johnson doesn't suggest either that Darwin is to blame for subsequent history or that the theory of evolution by natural selection is incorrect. For instance, he writes:

The truth is, Origin is a book that, with total success, embodies an exciting idea and had a devastating intellectual and emotional impact on world society. The word devastating is accurate: It destroyed many comfortable assumptions, thus clearing space for new concepts and ideas to spring up in almost every subject. It acted like a force of nature itself, and by the end of January 1860, when the second edition sold out, it was quite beyond Darwin's control. Darwin became one of the formative thinkers of the twentieth century…affecting the way people thought about an immense variety of topics, often quite remote from his own preoccupations. (pp. 130-131)

In addition, to generally misrepresenting the book, Stern also quotes it out of context. As quoted above, Stern writes:

…Darwin’s book was allegedly relied upon by the Nazis in developing their racial theories…and Hitler apparently carried the theory of natural selection “to its logical conclusion.”

Whereas what Johnson actually wrote was: "Once in power, Hitler began a process that carried dysgenics to its logical conclusion (p. 135)", and Johnson had earlier referred to dysgenics as eugenics' "companion science, or pseudoscience" (p. 131). Now, perhaps Johnson could've been and should've been clearer that social Darwinism, eugenics, and dysgenics were at the very least dubious extensions of the theory of natural selection into ethics and politics rather than sciences, but he never made the outrageous claim that Stern attributed to him.

On the subject of communism, Stern again misleadingly quotes Johnson:

“Leading Communists,” moreover, “from Lenin to Trotsky to Stalin and Mao Tse-tung” considered evolution “essential to the self-respect of Communists."

Here's what Johnson wrote in context:

In the first half of the twentieth century, the notion of struggle being natural and essential in the improvement of humanity was a belief that ran right across the political spectrum. The delight with which Engels and Marx pounced upon the Origin the week of its appearance was succeeded by a continuing interest among leading Communists, from Lenin and Trotsky to Stalin and Mao Tse-tung, in Darwin's theory of natural selection as justification for the class struggle. It was essential to the self-respect of Communists to believe that their ideology was scientific, and Darwin provided the stiffening to the scaffold of laws and dialectic they erected around their seizure and retention of power. (pp. 135-136)

This is perhaps not as clear as it could be, but communists did conceive of communism as a science, and attempting to claim some relation with an established science is typical of pseudoscience. Darwin certainly is no more to blame for the pseudoscientific misuse of the notion of the struggle for existence than Einstein is to blame for pseudoscientific invocations of relativity, or Planck for quantum quackery.

I still think that Johnson's brief mentions of Stalin, together with the longer discussion of Soviet communism, is misleading without also mentioning Lysenko. Johnson may well be right about the relation of the idea of the struggle for existence with the notion of class struggle, but he rightly traces the former idea back to Malthus, not Darwin. If Johnson was going to evoke Stalin and the Soviet Union at all, he should have made it clear that Stalin specifically rejected Darwin's theory in favor of an earlier theory of evolution and an older idea of the struggle for existence which predated Darwin.

It's also clear that the man who could write the following passage does not doubt the truth of Darwinism:

…Darwin's theory remains one of the great scientific explanations of all time, and its confirmation and blending with Mendelism, which supplied its missing dimension, has produced the science of genetics, moving at accelerating speed to illuminate the mysteries of life. Darwin is here to stay among the select band of leaders who dispersed the darkness of ignorance. (p. 150)

Johnson's book is not one that I would necessarily recommend, even as a brief biography of Darwin, but it's certainly not the unrecognizable caricature that Stern reviewed. Of course, none of this is to deny the fallaciousness of the two arguments I discussed above, but to make it clear that Johnson is not guilty of them. Some creationists, however, have indeed argued in this way; for instance, see the Example for the fallacy of appeal to consequences.

Source: Paul Johnson, Darwin: Portrait of a Genius (2012)

Update (11/26/2012): Following up on my claim at the end of the previous update: surprisingly, I found on The Fallacy Files' library's "Shelf of Shame" a book called Evolution's Fatal Fruit by Tom DeRosa―I had forgotten about it. The shelf is reserved for books based entirely, or almost so, on logical fallacies and DeRosa's book fits well alongside The Abortion Holocaust and Comet of Nostradamus: August, 2004―Impact!. It could almost be the book that Stern was reviewing, except of course for the out-of-context quotes of Johnson.

Despite its title, DeRosa's book is mostly a short biography of Darwin, interspersed with creationist comments. I'm no expert on Darwin but, as far as I can tell, DeRosa's account of Darwin's life is accurate. It's only the last few chapters that attempt to link Darwin to the Holocaust. Of course, as a way of trying to gain credibility, Hitler and other antisemites associated their pseudoscientific racist beliefs with the scientific theory of evolution. However, this is no different than murderers who use the Bible, or other religious works, as justification for their crimes.

The Foreword to the book is attributed to the late televangelist D. James Kennedy, whose Coral Ridge Ministries published it. While DeRosa only mentions communism in passing, Kennedy blames it on Darwin also:

…[T]he two most notorious and blood-soaked political movements of the twentieth century, Nazism and Communism, both…were animated by the idea of evolution. It was Darwin's theory―carried to its logical conclusion―that led to the death of some 11 million people at the hands of German Nazis. (P. 8)

Of course, Kennedy doesn't explain how the Holocaust is a "logical conclusion" of Darwin's theory, but given his weak grasp of logic that's not surprising. As an example of DeRosa's equally poor reasoning, consider the following startling passage:

…[I]f we assume that the earth is old, we are also saying that death came before sin. That creates an enormous theological problem. If the fossil record is the geological account of a series of catastrophes that befell the earth before the fall of man, then death occurred before Adam. But how could everything be "good," as God stated six times in the first chapter of Genesis, if the earth contained a history of catastrophic death?

God: What I tell you six times is true! Would DeRosa be less convinced that everything was "good" if God had only stated it five times? Sorry for the interruption; back to DeRosa:

The fossil record represents death and destruction that can only come from the judgment of God on man's sin. How could there be death before sin? The fossils collected represent God's judgment and only make sense after Genesis 3, where man's fall is recorded. (P. 63)

On this basis, DeRosa concludes that the fossil record must have been deposited in the forty days and forty nights of the Noachic flood, rather than in millions of years. He treats the recognition by geologists that life on earth is millions of years old as a sort of original sin, since it went against the Bible and opened up the time frame needed for evolution to produce the abundance of life we see around us and in the fossil record. However, DeRosa's method of doing science by first checking to be sure that a theory is consistent with the book of Genesis would mean throwing out all of astronomy since Copernicus, which is what the Catholic church tried to do for centuries. It's amazing that anyone in the 21st century can still think this way.

November 11th, 2012 (Permalink)

Billboard

People for the Ethical Treatment of Animals (PETA) is back with another ad campaign based on a bad analogy (see the picture of the billboard to your right). I suppose a farm kid might keep a turkey as a pet and become fond of it, but for most children this is a big difference between their pet dogs and turkeys. If PETA just wanted to make a comparison between dogs and turkeys as animals, they could have asked the kids: "If you wouldn't eat a dog, why eat a turkey?" Of course, some children live in cultures where dogs are eaten, and some have even grown up to be president.

Source: "PETA Thanksgiving billboard asks kids: Would you eat your dog?", Fox News, 11/10/2012

Resources:

• Fallacies in the News, 3/3/2003
• What's New?, 8/19/2005
• PETA Propaganda, 8/23/2008

Fallacy: Weak Analogy

November 7th, 2012 (Permalink)

A Third Puzzling List

Here's another strange list of sentences:

1. At least one of the statements on this list is false.
2. At least two of the statements on this list are false.
3. At least three of the statements on this list are false.
4. At least four of the statements on this list are false.

Assuming that each of the sentences on this list is true or false, how many are true and how many false? Which are true and which are false, if any?

Solution

Resources:

• A Puzzling List, 9/5/2012
• A Second Puzzling List, 10/30/2012

November 2nd, 2012 (Permalink)

What's new?

I've created a new page, "Stalking the Wild Argument" (see the Resource, below), as a sort of companion for the page of examples, "Stalking the Wild Fallacy". The new page will be a repository for examples of arguments taken from the "wild"―that is, real life. However, these examples will also be rather "wild" in a different sense: longer, subtler, and requiring more explanation than those on the examples page, which should be mostly self-explanatory.

Resource: "Stalking the Wild Argument"

Update (11/3/2012): I've added a new way of accessing the weblog archives by means of a scrollable list near the bottom of the navigation pane to your left. Just scroll down the list until you find the month you want, then click on it. The old archives page will remain in place until I've deleted all links to it, at which point I'll delete the page itself.

Solution to a Third Puzzling List: If each of these sentences is true or false, then the first two must be true and the last two false.

To see why, first notice that if any sentence on the list is true then all previous sentences must also be true. For example, if the second sentence is true then the first sentence must also be true, since from the fact that at least two sentences are false it follows that at least one is. This means that there are only five possible permutations of true and false that need to be considered:

1. All false: If this were the case, than all of the sentences would also be true, which is impossible.
2. First sentence true, the rest false: In this case, three of the sentences are false, which means that the second and third sentences would be true instead of false.
3. The first two sentences true, the last two false: This is the only consistent distribution of truth and falsehood to the list of sentences.
4. The first three sentences true, the last false: In this case, only one of the sentences is false, so the second and third sentences would be false rather than true.
5. All true: In this case, all four sentences would be false, since that's what the last one says.

Source: Martin Gardner, Knotted Doughnuts and Other Mathematical Entertainments (1986). The puzzle was suggested by one on page 70.

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