A crank's favorite gambit: Falsus in uno, falsus in omnibus

Perhaps you've seen it. Certainly if you've seen the "arguments" of Holocaust deniers, you've seen it. The desperate attempt to find one piece of testimony, data, or evidence that does not support conventional science or history. For example, a Holocaust denier will zero in on an eyewitness account of either a death camp or a Nazi atrocity that doesn't quite add up. Alternatively, he will make much of the discovery of a false "Holocaust survivor," as if finding out that someone lying about having survived the Holocaust somehow invalidates its historicity.

For example:

For half a century now historians have told us that during World War II the Nazis had a policy to exterminate the Jews of Europe, along with homosexuals and Gypsies. We are told that millions were "gassed" at German camps such as Auschwitz and Treblinka.

We have been told that the ghastly process of mass murder was also carried out in Belzec, Buchenwald and Sobibor. And aren't there thousands of survivors who "escaped the gas ovens" and swear that all this is true?

And didn't the Nazis make lamp shades from human skin, and manufacture soap from the fat of exterminated Jews? Of course, you may answer, everyone knows it. After all, aren't such bars of "Jewish soap" on display in museums in Israel and other countries? How can there be any doubt?

"Falsus in uno, falsus in omnibus," or "false in one thing, false in everything," was a Roman legal principle. If a witness may not be believed in one thing, he should not be believed in anything. This principle is as valid today as it was two thousand years ago.

With this in mind, I invite you to read the essay below, condensed from an article by historian Mark Weber that originally appeared in the Summer 1991 issue of The Journal of Historical Review. I urge you to consider whether any of the individuals or institutions that have contributed to the perpetuation of the debasing "human soap" hoax deserve to be believed about anything they say about the "Holocaust."

"Any of the institutions or individuals"? That's cutting with a rather broad swath, don't you think? For one thing, whether or not there were attempts to make soap out of human fat by the Nazis (there were, but only small scale attempts, experiments or pilot projects, if you will) is irrelevant to the historicity of the Holocaust and the fact that the Nazis had a program to exterminate European Jewry that very nearly succeeded. That the myth of "millions of Jews being turned into soap" became so commonplace and pervasive outside of historical circles is similarly irrelevant to the historicity of the Holocaust, but it provides deniers an excuse to discount everything from sources that ever came from any source that ever accepted such conclusions.

Yes, indeed. Falsus in uno, falsus in omnibus (FIUFIO). False in one thing, false in everything. That's the denier's trick (and that of many other forms of cranks). Gord McFee explained its use well in a discussion of why Holocaust "revisionism" isn't:

Since...the amount of empirical evidence for the Holocaust is so overwhelming, the "revisionists" must throw in another dismissal trick. This has been called the "falsus in uno, falsus in omnibus" condition (one thing mistaken equals all things mistaken). It means, for example, that if any single piece of survivor evidence can be shown to be wrong, all survivor evidence is wrong and is to be dismissed. If any Nazi official lied about an aspect of the Holocaust (on-topic or not), all Nazi officials lied, and anything Nazis said after the war is dismissed. If any Nazi can be shown to have been tortured or mistreated, they all were and anything they said is invalid.

Sound familiar?

Well, certainly, creationists are not above misusing this principle:

The forged Protamoeba primitiva, the alleged missing-link cell, and the plagiarized then forged embryo drawings that alleged evolutionary recapitulation, and the forged industrial melanism, and the forged molecular clock, and the fraudulent Stanley Miller experiment, and the plagiarized then forged skeletal evidence of ape to man, and the forged Piltdown man, and the forged Nebraska man, and the forged Pekin man, and the travesty of exhibiting an African pygmy in the Monkey House of the Bronx Zoo as the missing link, and the fact that Oxnard in 1975 and Mastropaolo in 2002 proved that all ape-men must be frauds or forgeries, and the fact that Francesco Redi in 1665 and Louis Pasteur in 1864 and John Tyndall in 1877 disproved evolution with experiments that have never been overturned.

All so-called evidence to support evolution qualifies as frauds or forgeries and was given scientific names with the express purpose to deceive. Falsus in uno falsus in omnibus.

Yes, how often have we seen creationists (whether of the "intelligent design" or old-fashioned young earth varieties) pointing out the Piltdown man (never mind that the fraud of the Piltdown man was revealed by scientists, not creationists) or various pieces of evidence that do not fit or may not be true, pointing to it, and then seemingly claiming that that fraud or scientific error invalidates the whole of the theory of evolution? How often do we hear "intelligent design" advocates attacking one shortcoming of evolutionary theory (whether real, exaggerated, or even made up out of whole cloth) and then implying that this shortcoming demands that the whole theory must be called into question, all the while conveniently ignoring all the other overwhelming evidence supporting evolution and that their alleged flaw is not of the variety of evidence that could falsify evolutionary theory.

But FIUFIO is a fallacious technique used not just by Holocaust deniers and creationists. Alties are fond of it too, as do many other varieties of cranks. A particular favorite variant of this ploy among alties is to argue that conventional medicine has been wrong about the cause of a disease, pointing to that as a reason that we should not trust the present consensus about the cause or treatment of a disease and arguing by implication that their "alt-med" therapy works. (Conveniently, they forget that, even if they're correct about science being wrong, that does not absolve them of the obligation to show that their therapy works.) A particular favorite example of this ploy is to point out how medicine was wrong about the cause of duodenal ulcers, having previously thought them due to diet or other predilections until it was shown over the last 20 years or so that most cases of such ulcers are caused by a bacterium, H. pylori. Never mind that it was science, not alties, that figured out the own error and that treatments used for duodenal ulcers before the discovery of H. pylori were in fact fairly effective (just not as effective as the treatments we have today and all too often requiring surgery).

Here's the core problem. FIUFIO is a legal principle, not a scientific or investigative principle. It is primarily used (and makes sense) in the courtroom. That's why lawyers are so aggressive at trying to impeach the credibility of a witness (and lawyers on the other side labor so hard to prevent that from happening). If a witness can be shown to have been mistaken or to have lied about one thing, then by the principle of FIUFIO, it is reasonable to question everything else in that witness' testimony. In a criminal case such questions could easily be enough to cast "reasonable doubt" on the testimony. The problem is, this principle doesn't work in science. Why? The scientific literature literature is littered with papers whose results were later shown to be either incorrect or only partially correct. In most cases, being incorrect doesn't mean the scientists were lying, and it is the totality of the evidence that must be weighed. Moreover, it is not valid to treat all of science as a single source. Science is not a single witness that can be interrogated. Well-accepted scientific theories (like evolution, for example) are supported by many interweaving lines of evidence from many different sources. If you impeach one minor source or piece of data, that does not invalidate the rest of the supporting data. True, there are some pieces of data that, if ever found, would cast serious doubt on the theory of evolution, but that is never the sort of data that ID creationists present. The same is true of the pieces of data "casting doubt" upon the Holocaust trumpeted by Holocaust deniers and of pieces of data trumpted by alties casting doubt on the efficacy of conventional medicine. Finally, when scientists find inconsistencies in the data supporting a hypothesis or theory, they do not reject the entire theory out of hand in this manner, as cranks do. Rather, they use such anomalous pieces of data or experimental results as a chance to improve our understanding of a phenomenon. They see if the theory can be modified to account for the observation. They make hypotheses about potential explanations of the anomalous observations and then test them experimentally. If they see if a new theory with better predictive power and utility than the old can be developed that takes account fo the new observations.

In actuality, when used by alties or creationists, FIUFIO boils down to being simply a subtype of the old crank favorite fallacious argument of "science was wrong before." This particular fallacy depends on the mistaken belief that there is absolute truth in science, when in fact all scientific knowledge is provisional and vulnerable to be proven incorrect by future experiments or evidence. That self-correcting mechanism of science is not a weakness at all, but rather sciences' greatest strength, in which present concepts and theories are constantly subjected to testing and attempts to falsify them. Those hypotheses that can stand up to such attempts become accepted as closer to the "truth" than previous understandings (and may even reach the level of being called a theory), and, with each successive iteration, scientific understanding eliminates error and comes closer to the way things "really are":

There are many complex areas of inquiry and finding answers is not easy. Initial ideas and hypotheses may be quite wrong; however, where they are shown to be wrong, they will be amended and retested. In this process, what happens is that an absolutely true answer may not be found, but we get closer to what is true every step of the way by being less wrong than before.

By rejecting theories and hypotheses that can be shown to be false and replacing them with others that stand up to attempts to prove them wrong (note: not attempts to prove them right. See: confirmation fallacy), we can accept them as being provisionally true. Truth, by definition, could never be shown to be wrong. This is why a scientific theory that cannot currently be shown to be wrong is accepted as provisionally true.

To argue that science can't prove things to be 100% true is fine, but for people to use it as an argument to give validity to completely untenable ideas is fallacious. Both their ideas and science may be wrong; but science is highly likely to be far less wrong than they are.

Indeed. Or as Skeptico put it:

As well as being a flawed argument, it [the "science was wrong before" argument] also shows ignorance of how science works. Yes, science has been wrong, but the scientific method is self-correcting. And it is always scientists who have unearthed new evidence who do the correcting, never people who ignore the scientific method.

Ironically it also shows up the strength of science and the weakness of believer methods. For example, compare the way scientific errors are discovered and corrected, with what happens in, for example, astrology or alternative medicine. In those fields no errors are ever corrected for the simple reason that no one ever critically tests those beliefs to see if they even contain errors. Errors are a permanent feature of those beliefs. Error recognition and correction is a strength of science.

In addition, FIUFIO creates a false dichotomy regarding scientific or historical understanding: Either everything is correct, or nothing is true. A single inconsistency, no matter how peripheral or unrelated, is reason enough for cranks to make a sweeping claim that the whole edifice is crumbling. Clearly this is far too simplistic and excludes other possibilities. The ridiculousness of such an approach is illustrated well by Holocaust deniers who point to errors or exaggerations in the testimony of a few survivors (or point to the occasional charlatan who pretended to be a Holocaust survivor but was not) and try to argue that such errors invalidate the historicity of the Holocaust.

In the end, if you hear hear someone using either FIUFIO or the "science was wrong before" gambits, you can be reasonably sure that their position is not supported by evidence. If it were, they would cite that evidence in support of their position, rather than retreating to such fallacies to try to support their assertions. Yes, science and history have been wrong before--sometimes spectacularly, amazingly wrong. But that doesn't automatically make the crank who invokes such past mistakes right.