. . . part 2 . . .

Argument ad Baculum or "Argument from the stick", Latin.

This fallacy is committed whenever force or the threat of it is introduced into a rational discussion in order to derail it. For example, extremists will disrupt debates by starting riots when their side appears to be losing. Even audience members "shouting down" a debater whom they disagree with in order to prevent a case from being heard are resorting to "ad baculum".

Appeal to Emotion

Essentially this is any argument that a claim is true because it causes or is associated with positive emotions, or that its converse is associated with negative emotions.

A common use of this fallacy is to justify belief in the existence of god. Many argue that god must exist because belief in god makes life worth living, or at least causes happiness and contentment. Also people might argue that they believe in an afterlife because they cannot deal with the alternative that death is final.

Argument from final outcome or consequences

Such arguments (also called teleological) are based on a reversal of cause and effect, because they argue that something is caused by the ultimate effect that it has, or purpose that is serves. This argument takes some permutation of the form that if a claim were either true or untrue, then the consequences would either be good or bad, and therefore what is true is what leads to either achieving a good outcome or avoiding a bad outcome.

For example, Christian creationists have argued that evolution must be wrong because if it were true it would lead to immorality.

Argument from final outcome or consequences subtype: Argument from Benefit

Another common, and perhaps more subtle, form of this logical fallacy is the notion that if someone or some entity benefited from an event they must have caused the event.

This fallacy is commonly invoked in the context of the JFK assassination in order to support an alleged conspiracy. The argument is that if someone benefited from the assassination of JFK they must have been involved in a conspiracy to carry out the assassination.

Argument from final outcome or consequences subtype: Appeal to Fear

The appeal to fear is an argument from consequences, but in this case the consequences are individually relevant – an outcome to be personally feared. For example, proselytisers often argue that you should accept the claims of their religion for if you reject them you risk eternal damnation.

Argument from final outcome or consequences subtype: Appeal to Flattery

Like the appeal to fear, this is a personalised version of the argument from final consequences, this time positive rather than negative. This logical fallacy is the attempt to convince someone of a claim because of implied flattery.

For example, alleged psychics may support their claims of psychic abilities by claiming that they sense psychic potential in the person they are trying to convince.

Argument from final outcome or consequences subtype: Appeal to Pity

This fallacy attempts to support a claim out of pity, sympathy, or even obligation to some person or group.

For example, some proponents of Gulf War Syndrome have argued that we should accept the reality of this syndrome because we owe it to our veterans who fought for us in the Gulf War. Another example is the claim that silicone breast implants cause auto-immune disease, despite all evidence to the contrary. During this debate there were many appeals to pity for the victims of silicone breast implants. This can also be considered the fallacy of assuming the conclusion, because having sympathy for the victims of silicone breast implants assumes they are victims, which is the very matter of debate.

Post-hoc ergo propter hoc

This is perhaps the most common of logical fallacies. It follows the basic format of A preceded B, therefore A caused B, and therefore assumes cause and effect for two events just because they are temporally related (the Latin translates to “after this, therefore because of this”).

This logical fallacy is frequently invoked when defending various forms of alternative medicine - I was sick, I took treatment A, I got better, therefore treatment A made me better. It is possible to have recovered from an illness without any treatment.

Keep in mind (as with the correlation and causation fallacy described below) it is possible that A did cause B. The logical fallacy is in assuming causation. It is still valid to argue for causation if there is independent evidence to support a causal relationship over other interpretations, such as coincidence.

Confusing correlation with causation

This is similar to the post-hoc fallacy in that it assumes cause and effect for two variables simply because they occur together. This fallacy is often used to give a statistical correlation a causal interpretation. For example, during the 1990’s both religious attendance and illegal drug use were on the rise. It would be a fallacy to conclude that therefore, religious attendance causes illegal drug use. It is also possible that drug use leads to an increase in religious attendance, or that both drug use and religious attendance are increased by a third variable, such as an increase in societal unrest, or even just population. It is also possible that both variables are independent of one another, and it is mere coincidence that they are both increasing at the same time.

This fallacy, however, has a tendency to be abused, or applied inappropriately, to deny all statistical evidence. In fact this constitutes a logical fallacy in itself, the denial of causation. This abuse takes two basic forms.

The first is to deny the significance of correlations that are demonstrated with prospective controlled data, such as would be acquired during a clinical experiment. The problem with assuming cause and effect from mere correlation is not that a causal relationship is impossible; it’s just that there are other variables that must be considered and not ruled out a-priori. A controlled trial, however, by its design attempts to control for as many variables as possible in order to maximise the probability that a positive correlation is in fact due to a causation.

Furthermore even with only statistical evidence it is still possible to build a strong scientific case for a specific cause. The way to do this is to look at multiple independent correlations to see if they all point to the same causal relationship.

For example, it was observed that cigarette smoking correlates with getting lung cancer. The tobacco industry, invoking the “correlation is not causation” logical fallacy, argued that this did not prove causation. They offered as an alternate explanation “factor x”, a third variable that causes both smoking and lung cancer. But we can make predictions based upon the smoking causes cancer hypothesis. If this is the correct causal relationship, then duration of smoking should correlate with cancer risk, quitting smoking should decrease cancer risk, smoking unfiltered cigarettes should have a higher cancer risk than filtered cigarettes, etc. If all of these correlations turn out to be true, which they are, then the smoking causes cancer hypothesis is supported above other possible causal relationship and it is not a logical fallacy to conclude from this evidence that smoking probably causes lung cancer.

“As an example to others, and not that I care for moderation myself, it has always been my rule never to smoke when asleep and never to refrain when awake.”
Mark Twain - 70th birthday speech

Special pleading, or ad-hoc reasoning

This is a subtle fallacy which is often difficult to recognise. In essence, it is the arbitrary introduction of new elements into an argument in order to jerry rig them, or fix them so that they appear valid.

A good example of this is the ad-hoc dismissal of negative test results. For example, one might argue that ESP has never been demonstrated under adequate test conditions, therefore ESP is not a genuine phenomenon. Defenders of ESP have attempted to counter this argument by introducing the arbitrary premise that ESP does not work in the presence of sceptics. This fallacy is often taken to ridiculous extremes, and more and more bizarre ad hoc elements are added to explain experimental failures or logical inconsistencies.

Two Wrongs make a Right or Tu quoque (you too)

This is an attempt to justify wrong action because someone else also does it. “My evidence may be invalid, but so is yours.” This fallacy is frequently committed by proponents of various alternative medicine modalities, who argue that even though their therapies may lack evidence some mainstream treatments also lack evidence.

Ad hominem

This is an argument that attempts to counter another’s claims or conclusions by attacking the person, rather than addressing the argument itself. Taken broadly, this fallacy can be any argument that a person’s claims is false because of a negative quality possessed by the person. True believers will often commit this fallacy by countering the arguments of sceptics by stating that sceptics are closed minded. Sceptics, on the other hand, may fall into the trap of dismissing the claims of UFO believers, for example, by stating that people who believe in UFO's are crazy or stupid.

Sometimes this fallacy can be more subtle. For example, undesired research results can be dismissed because the researchers have an apparent conflict of interest. While true conflicts are a legitimate concern, the use of even minor potential conflicts to dismiss research finding a-priori is little more than an ad hominem logical fallacy.

Subtype of Ad hominem: Argument from prior error

This form of ad hominem logical fallacy argues that the current claims of a person or group are incorrect because of errors committed in the past.

Creationists, for example, often point to fossil frauds, or the discovery of living coelacanth previously thought to be extinct to counter the current evidence for evolution.

Ad ignorantum

The argument from ignorance basically states that a specific belief is true because we don't know that it isn't true.

Defenders of extrasensory perception, for example, will often overemphasise how much we do not know about the human brain. It is therefore possible, they argue, that the brain may be capable of transmitting signals at a distance.

UFO proponents are probably the most frequent violators of this fallacy. Almost all UFO eyewitness evidence is ultimately an argument from ignorance – lights or objects sighted in the sky are unknown, and therefore they are alien spacecraft.

Intelligent design is almost entirely based upon this fallacy. The core argument for intelligent design is that there are biological structures that have not been fully explained by evolutionary theory, therefore a powerful intelligent designer must have created them.

Confusing absence of evidence with evidence of absence

This fallacy cuts both ways. In other words, one might assume that absence of evidence is a compelling argument against the reality of a claim or phenomenon. On the other hand, however, one might dismiss the absence of evidence as having no significance – as not being evidence of absence.

In reality, the absence of evidence can only be properly considered in the context of how likely it is that evidence should exist. You must therefore consider how thoroughly evidence has been looked for, and if the tools and techniques employed are capable of finding evidence. For example, if you dredge the bottom of a sea with a net that has one inch holes in order to survey the life living in that sea, you will likely not come up with any creatures smaller than one inch in size. It would not be logical to then conclude that there are no fish smaller than one inch living in that sea.

This fallacy is central to the Bigfoot debate. Believers in Bigfoot claim that the absence of hard evidence of Bigfoot is not evidence that Bigfoot does not exist. Sceptics, however, argue that a population of large mammals living in North America should produce some evidence, such as the occasional corpse.

Argument from Personal Incredulity

I cannot explain, imagine, or understand this, therefore it cannot be true. However, reality is not limited by our ability to comprehend it, or by our comfort with it. Creationists are fond of arguing, for example, that evolution is false because they cannot imagine the complexity of life resulting from blind natural processes, but that does not mean life did not evolve.

Argument from Personal Incredulity Subtype: Appeal to Ridicule

This form of the argument from personal incredulity argues that a claim is false because it seems ridiculous. Of course, some claims are ridiculous and it is legitimate to arrive at such a conclusion after careful examination of the logic and evidence. However, it is a fallacy to dismiss a claim a-priori simply by labelling it ridiculous or absurd. Many ideas that initially seemed far-fetched, such as the notion that invisible tiny organisms cause disease, or that space and time are relative and not constant, turned out eventually to be proven scientifically valid.

Confusing currently unexplained with unexplainable

Because we do not currently have an adequate explanation for a phenomenon does not mean that it is forever unexplainable, or that it therefore defies the laws of nature or requires a paranormal explanation. An example of this is the "God of the Gaps" strategy of creationists that whatever we cannot currently explain is unexplainable and was therefore an act of god. The history of science has taught us, however, that even the most intransigent of natural mysteries may eventually yield to scientific investigation.

False Dichotomy

This fallacy consists of arbitrarily reducing a set of many possibilities to only two. For example, evolution is not possible, therefore we must have been created (assumes these are the only two possibilities). Actually, this fallacy can apply to any premature reduction in the possible set of explanations for a phenomenon – not necessarily down to only two possibilities. UFO proponents, for example, will often analyse a sighting by saying the object was not a plane, not a balloon, and not celestial object, therefore it was a flying saucer. They are limiting the set of possibilities to a few easily dismissed choices, and the desired choice, while ignoring the many other possibilities.

This fallacy can also be used to oversimplify a continuum of variation to two black and white choices. For example, science and pseudo-science are not two discrete entities, but rather the methods and claims of all those who attempt to explain reality fall along a continuum from one extreme to the other.

Douglas Adams uses this kind of argument in the following;

“Now it is such a bizarrely improbably coincidence that anything so mindbogglingly useful [the Babel fish] could have evolved by chance that some thinkers have chosen to see it as a final and clinching proof of the non-existence of God.
     The argument goes something like this: "I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing."
     "But," says Man, "the Babel fish is a dead give-away isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED"
     "Oh dear," says God, "I hadn't thought of that," and promptly vanishes in a puff of logic.
The Hitch Hiker's Guide to the Galaxy (book one of the Hitch Hiker's Guide to the Galaxy series), p. 50

False Continuum

This is the idea that because there is no definitive demarcation line between two extremes, that the distinction between the extremes is not real or meaningful: There is a fuzzy line between cults and religion, therefore they are really the same thing. This fallacy is especially important to understand in the context of medicine; most human traits vary according to a Bell curve of variation. “Unhealthy” is often defined as being too far out to one extreme or the other. The false continuum logical fallacy is sometimes used to argue that these extremes are merely part of a continuum of variation, and therefore have no meaning or significance. However, this is like saying that “short” and “tall” have no meaning because human height is a continuum of variation. Blood pressure is a good example. We can meaningfully define high blood pressure because it correlates with increased risk of certain disease, such as heart attacks, even though high blood pressure is at the upper end of a continuum of variation.

In part this logical fallacy represents discomfort with the concept of a fuzzy line of demarcation between two extremes. But such fuzzy lines are more the rule than the exception in this complex world.

Inconsistency

Applying criteria or rules to one belief, claim, argument, or position but not to others. For example, some consumer advocates argue that we need stronger regulation of prescription drugs to ensure their safety and effectiveness, but at the same time argue that medicinal herbs (which are pharmacological agents – drugs) should be sold with no regulation for either safety or effectiveness.

The Moving Goal-post

A method of denial - arbitrarily moving the criteria for "proof" or acceptance out of range of whatever evidence currently exists.

Creationists are most famous for this fallacy. In Darwin’s time they argued that in order for evolution to be true there would need to be a method of inheritance that allowed for new variation to persist and propagate, rather than merely become diluted in the larger population.

Mendel’s discovery of “genes” fit the bill. They then argued that if evolution were true there should be many transitional fossils, but no number of transitional fossil discoveries seems to be enough to satisfy them.

Intelligent Designers now argue that evolution cannot explain the appearance of biochemical pathways and microscopic structures – but as these pathways and structures are rapidly being explained they simply continue to move the goal-post further and further back.

Reductio ad absurdum

In formal logic, the reductio ad absurdum is a legitimate argument. It follows the form that if the premises are assumed to be true it necessarily leads to an absurd (false) conclusion and therefore one or more premises must be false.

The term is now often used to refer to the abuse of this style of argument, by stretching the logic in order to force an absurd conclusion. For example a UFO enthusiast once argued that if I am sceptical about the existence of alien visitors, I must also be sceptical of the existence of the Great Wall of China, since I have not personally seen either. This is a false reductio ad absurdum because he is ignoring evidence other than personal eyewitness evidence, and also logical inference. In short, being sceptical of UFO's does not require rejecting the existence of the Great Wall.

Slippery Slope

This logical fallacy is the argument that a position is not consistent or tenable because accepting the position means that the extreme of the position must also be accepted. But moderate positions do not necessarily lead down the slippery slope to the extreme. There may be legitimate reasons to accept intermediate positions.

For example, those, like Thomas Szasz, who believe that mental illness does not exist have argued that if we classify depression as an illness that will lead to governments classifying political protest as a mental illness, because they are both mental states. This slippery slope argument ignores the important differences between a debilitating mood disorder and a political opinion.

False Analogy

This is any argument that is based upon an analogy that is false because of important differences between the situations being compared.

Straw Man

This is arguing against a position which you create specifically to be easy to argue against, rather than the position actually held by those who oppose your point of view. Therefore this consists of misrepresenting an opposing view in such a way that it is vulnerable to attack, because, for example, it is based upon flimsy evidence or invalid logic.

UFO proponents (and many other true believers) have often dismissed sceptics by saying that they reject anything they cannot see with their own eyes. This is a straw man because scientists accept logical inference as a legitimate method.

I have never seen a black hole but I accept their reality because the evidence strongly infers their existence.

Tautology

A tautology is an argument that utilises circular reasoning, which means that the conclusion is also its own premise. The structure of such arguments is A=B therefore A=B, although the premise and conclusion might be formulated differently so it is not immediately apparent as such. For example, saying that therapeutic touch works because it manipulates the life force is a tautology because the definition of therapeutic touch is the alleged manipulation (without touching) of the life force.

Conclusion

The more you practice examining arguments for their premises and logical fallacies, the better you will get. I think you will find it is the best method for resolving differences in factual conclusions. It is also helpful in that it can take away the personal emotional content of an argument; if the focus is on facts and logic, the arguments tend to be less personal.

Finally, the most important arguments to examine in this way are your own.

Original article by Steven Novella, MD, (http://www.theness.com/articles.asp?id=38)

Posted by the New England Skeptical Society, 5/8/2006 (http://www.theness.com/)

Edited and updated by Psiloiordinary, 2006

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