Bad Logic

Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay
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Just about every logical fallacy ever imagined turns up in pseudoscience, including:

"Galileo Fallacy"
"They laughed at Galileo, and he was right. They laugh at me, therefore I must be right." Variation common in education: "Einstein didn't do well in school, therefore any kid who does poorly in school is like Einstein."
"Residue Fallacy"
After all the bad data, fakes, and errors are weeded out, there are still a few unexplained cases that indicate a real phenomenon. More pertinent question: if 95 per cent of the data is bad, what makes you think the remainder isn't as well?
Explanation by Default
Science can't explain it, but I can, therefore my explanation must be right. Most of the time, people who adopt this line don't bother to tell you science can explain it.
Distortion of the Term "Theory"
A theory is any body of ideas in science. It does not mean a guess or hypothesis. If you believe a "theory" is unproven, don't drive across any bridges. The engineers used Stress Theory to design the bridge.
Attacks on Inference and Deduction
If we're restricted to only what we see directly, we will never know very much about the world. Observation by an untrained witness is much more likely to be wrong than inference or deduction by a trained analyst.
Exaggeration of Uncertainty
Much of pseudoscience is designed to create a fog in which things look so fuzzy that it looks like you can pick any belief you like.
Catch-22 Arguments, Buzzwords
Often used in discourse other than pseudoscience. Terms like "vested interest", "politically correct", "socialist", "racist", "sexist", "homophobic", and so on poison the climate of debate.
Conspiratorial Outlook
If there's one single, nearly infallible sign of the crank, it's a belief in conspiracies.

Selective Use of Data

Pseudoscientists are often very selective in their use of the data. Believers in the Biblical Deluge use flood legends from around the world in support of a worldwide flood in recent times, but they take flood legends literally and ignore other types, like legends of visitors from the skies. Erich von Daniken, on the other hand, takes accounts of celestial visitors seriously but ignores the flood myths.

In general the pseudoscientist looks only for evidence that supports his theory. Real scientists look for evidence against their theories as well. Even if they want desperately to see their theories accepted, they know full well that their opponents will be looking for weak spots; better to anticipate criticism or even junk a cherished belief rather than be blown out of the water by somebody else. The pseudoscientist not only looks only for confirmation, but he often takes a very broad view of confirmation. ESP researchers point to cases where subjects guess ESP cards with unusually high accuracy as evidence for ESP. If the test scores are unusually low, the phenomenon is called "avoidance" and is also considered evidence for ESP! Taken as a whole, the results of long-continued ESP experiments conform to pure chance, but the runs that are somehow unusual are singled out as evidence for ESP.

Failure to Test Theories

Pseudoscience is amazingly static; it tries to portray itself as daring and innovative, but actually it is conservative, unimaginative, and dull. Pseudoscientists spend most of their effort rehashing their original theory, rather than developing it, elaborating it, or trying to relate it to the rest of science. Despite fifty years of berating science for its refusal to accept Velikovsky, Velikovsky's supporters have yet to come up with a physically plausible mechanism for altering the orbits of the planets the way Velikovsky insists happened. UFO enthusiasts have spent years pressuring the Government to release supposedly secret data on extraterrestrial spacecraft, yet seem distressingly incapable of getting clear photographs of UFO's.

Erich von Daniken provided the single most spectacular example in all of pseudoscience of failing to follow up on a theory. In Chariots of the Gods?, he claimed "parts of a belt made of aluminum lay in a grave at Yungjen, China". Now if I were seriously interested in showing that early man had contact with a technologically advanced culture, this is exactly the sort of evidence I'd look for. Aluminum is very chemically reactive and very hard to extract from ores. It was not discovered until 1825, and not until 1886 was a way found, using electrolysis, to produce it cheaply. Aluminum would have been utterly beyond the capability of ancient civilizations on Earth to produce on their own. If von Daniken really wanted to demonstrate the existence of ancient visits by extraterrestrials, he should have been moving heaven and earth to document that aluminum belt! Instead, he dismissed it in one short sentence, provided no photograph, no references, didn't tell us where the belt is now, and indeed provided no proof at all that the belt really exists. This one example pretty well sums up the value of the ancient-astronaut theory, and pseudoscience in general.

Pseudoscientists often fail to perform the simplest checks on the workability of their theories. For example, scientific creationists attempt to get around radiometric ages of rocks by saying that atoms may have decayed faster early in the earth's history. But to fit the geologic time scale into the creationist time scale, radioactive decay would have to have been up to a million times faster. We now get about 0.1 rem of natural radiation from radioactive elements in the rocks each year. 500 to 1000 rem in a short time is fatal. With radioactive decay a million times faster, the annual dose rate just after creation would have been 10,000 rem, or a fatal dose of radiation in a few weeks. Creationists make no effort to address this problem.

In those rare cases where the pseudoscientist does check his ideas to see if they work, he has a ready excuse for failure. Two of Velikovsky's supporters, Lynn Rose and R.C. Vaughan, reported in Velikovsky Reconsidered on calculations in which they tried unsuccessfully to explain how the planets could have moved in accordance with Velikovsky's scenario and still end up in their present orbits. They wrote: "Let us not say that our relative ignorance at present of the processes that damp electromagnetic effects in the Solar System shows that Velikovsky is wrong ... At this point, it is largely a matter of attitude whether one sees these as vulnerable points of the theory or as strong opportunities for discovery ... We do not stand before a wall, we stand before a door". In other words, failure is success. Orwell would add: War is Peace -- Freedom is Slavery -- Ignorance is Strength -- Doublethink.

A Nation of Jailhouse Lawyers

The Irrelevance of the Courtroom

Creationist Philip Johnson, a lawyer, has written a number of books criticizing evolution from a legal standpoint. The competence of a lawyer or judge to evaluate scientific evidence is nearly nil, and the court system is poorly designed to deal with scientific issues. Scientists will not exclude valid data because the researcher didn't have a search warrant. If an investigation reveals a need to gather further data, scientists will go get it. A jury deliberating a technical issue can't ask the court to go perform an experiment. The legal concept of evidence is so artificial, and so geared to allowing the opposing sides to manipulate evidence, that it is intellectually almost worthless.

Freedom of Speech

The Constitution gives you the right to free speech. It gives your critics the right to rebut your claims or ignore you. As the late Hubert Humphrey once observed during the Sixties: "The right to free speech does not imply the right to be taken seriously. That depends on what is said." Nowhere in the Constitution is anyone guaranteed a right to freedom from criticism.

Criminal Cases

Pseudoscientists sometimes appeal to the dictum that an accused person is innocent until proven guilty. People are innocent until proven guilty; ideas are wrong until proven right.

Under our justice system, the State assumes the burden of proof in criminal cases. We have said, in effect, we would rather assume the risk of letting a guilty person go free than risk punishing an innocent person. The actual standard is "guilt beyond a reasonable doubt," a clear indication that there is such a thing as unreasonable doubt. For this reason, a smart lawyer will not attempt to deny the guilt of a client where the evidence is overwhelming, but will focus instead on mental illness, extenuating circumstances, and technical issues.

(What about cases where innocent people are punished? Tragically, short of abandoning law enforcement altogether, no system, however perfect, can possibly avoid an occasional miscarriage. Sometimes we misjudge the reasonableness of doubts.)

We can adopt the "guilty until proven innocent" standard because we as a society have decided to accept a certain level of risk. We can do that in cases where one party is the State. But what about conflicts between private parties?

Civil Cases

In conflicts between two private parties (Civil Law), we cannot automatically assign the burden of proof to one side or the other. In any such conflict, somebody will be angry at the outcome. If we weight the system too heavily in favor of the defendant (as was perhaps the case fifty years ago), we create a system where it becomes too easy to run roughshod over the rights of others. If we weight the system too heavily in favor of the plaintiff (as is the case now), we create a system where it becomes too easy to sue - and win - for the most frivolous reasons. And regardless of how ambiguous or unsatisfactory or incomplete the evidence is, the court will have to decide in favor of one side or the other.

One standard that is used in civil law is called Preponderance of the Evidence. I have a perfect record as an expert witness: one case, one loss. It involved a gas station accused of leaking gasoline into the ground water. The evidence was sketchy at best but the gas station had been found to have a leaky fitting during an inspection. Far from sufficient for a criminal case, but while there were plausible other sources for the gasoline, there was no convincing evidence that any of them were actually responsible. Based on the preponderance of the evidence, the gas station was found liable (and went out of business).

Preponderance of the evidence is a much better model for science than the criminal-law model. Despite all the efforts pseudoscientists devote to creating an appearance of "reasonable doubt", the preponderance of the evidence is that evolution happened, that UFO's are not extraterrestrial visitors, and that paranormal phenomena do not exist.

Another standard used in civil law is called Control of the Facts. Does it violate presumption of innocence to have to present records to show that you paid your taxes? No, and for a good reason. You could simply deny having any income at all, and merely by not keeping records, nobody could prove otherwise. You could discriminate, dump toxic waste, ship weapons to terrorists, and without records, nobody could prove a thing. So in civil law, the principle used is that everyone must maintain reasonable records to show compliance with the law. The person connected with an activity is in control of the facts, that is, in a position to document what goes on, and has a legal obligation to maintain documentation. (None of these admittedly good reasons diminish the fact that requiring a defendant to prove his innocence is profoundly unjust.)

However, when someone challenges established scientific ideas, science is cast in the role of defendant and the challenger is the plaintiff. Furthermore, since science can cite the evidence in support of its ideas, it's up to the challenger to produce the evidence to the contrary. Not only is it profoundly unjust to require a defendant (science, in this case) to prove his innocence, but the challenger of established science has control of the facts. The challenger is in the position to make the observations and collect the data needed to overturn established science.


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Created 3 February 1998, Last Update 3 February 1998

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