Dictionary of Logical Fallacies
|Fallacies of Relevance
|Fallacies of Ambiguity
|Other Informal Fallacies
- Accent [Amb]
- Accident [Rel]
- Affirmative Conclusion from Negative Premises [For]
- Affirming the Consequent [For]
- Ambiguous Collective [Rel]
- Amphiboly [Amb]
- Assumption Correction Assumption
- Baculum, Argumentum ad [Rel]
- Barking Cat
- Boolean Syndrome
- Broken Window [Tech]
- Converse Accident [Rel]
- Complex Question [Rel]
- Complexity Simplistic
- Composition [Amb]
- Columbus [Amb]
- Context Imposition
- Denying the Antecedent [For]
- Dictum Ex Post Facto
- Discarded Differentia
- Division [Amb]
- Equivocation [Amb]
- Exclusive Premises [For]
- Existential Fallacy [For]
- False Alternative
- False Attribution
- False Cause [Rel]
- Falsified Inductive Generalization
- Fidentia, Argumentum ad
- Flat Earth Navigation Syndrome
- Floating Abstraction
- Friedman's Fallacy
- Frozen Abstraction
- Gambler's Fallacy
- Government Absolutist
- Government Solipotence
- Gratuitous Inculpation
- Gravity Game
- Homily ad Hominem
- Hominem, ad - Abusive [Rel]
- Hominem, ad - Circumstantial [Rel]
- Ignorantiam, Argumentum ad [Rel]
- Ignoratio Elenchi [Rel]
- Ignoring Historical Example
- Ignoring Unit Percentages
- Illicit Process [For]
- Instantiation of the Unsuccessful
- Intimidation, Argument from
- Journalistic Fallacies
- Misericordiam, Argumentum ad [Rel]
- Moving Goalpost Syndrome
- Nirvana Fallacy
- Null Value
- Overlooking Secondary Consequences
- Petitio Principii [Rel]
- Populum, Argumentum ad [Rel]
- Post Hoc Ergo Propter Hoc [Rel]
- Post Hoc Nullificatio Pro Temperi
- Pretentious Antecedent
- Proof by Selected Instances
- Proving a Negative
- Quod Nimis Probat, Nihil Probat
- Reification of the Existent
- Reification of the Improbable
- Reification of the Possible
- Relative Privation
- Retrogressive Causation
- Selective Sampling
- Self Exclusion
- Shingle Speech
- Silence Implies Consent
- Spurious Causation
- Spurious Superficiality
- Stolen Concept
- Suppression of the Agent
- Thompson Invisibility Syndrome
- Tu Quoque
- Undistributed Middle [For]
- Unintended Self-Inclusion
- Variant Imagization
- Verecundiam, Argumentum ad [Rel]
- [Amb] This fallacy consists of shifting the meaning of a statement by changing the accent. E.g. "We should not speak ill of our friends" seems reasonable when read without any stress. If someone concludes that we may speak ill of people who are not our friends, then he has apparently switched premises by emphasizing the last word. Emphasizing other words (we,speak) yield yet other distinct meanings and conclusions. Quoting someone out of context is an example of this fallacy. Often a passage can only be correctly understood with its explanatory context, which sets the environment, sense and qualifications. Other examples of this fallacy: tabloid headlines ("Revolution in China" headline, continuing in small print "...not likely to occur soon."); advertising posters and ads ("PC System $800" banner, then in small print "keyboard, monitor, CD drive not included.")
- [Rel] This fallacy consists of applying a general rule to a particular case whose "accidental" qualities or circumstances render the rule inapplicable. If a homicidal maniac demands to know where I keep my gun, shouldn't I claim "I have no firearms," even if I really do? While "You should tell the truth" is an excellent heuristic, it is implicitly clear that it applys to civilized society and not life-or-death survival scenarios.
- [For] If either premise of a standard-form categorical syllogism is negative, then the conclusion must be negative. A syllogism which fails this commits the fallacy of drawing an affirmative conclusion from negative premises. An affirmative conclusion asserts that one class contains another in whole or part. Thus the premises must assert such containment via a third class containing the first and contained in the third. But this class inclusion can only be asserted by affirmative propositions.
- [For] The hypothetical syllogism "If A then B; A is true; Therefore B is true" is valid. It is called modus ponens meaning affirming the antecedent. A common error is to affirm the the consequent B instead of the antecedent A. This is the Fallacy of Affirming the Consequent. "If Bacon wrote Hamlet, then Bacon was a great writer; Bacon was a great writer; Therefore Bacon wrote Hamlet."
- [Rel] The use of a collective term without
any meaningful delimitation of the elements it subsumes. "We" "you" "they" and "the people" are the most widely used examples. This fallacy is especially devastating in the realm of political discussion, where its use renders impossible the task of discriminating among distinctly different groups of people. I often challenge those who commit this fallacy to eliminate from their discussion vocabulary all general collective terms, and each time they want to use such a term to use instead a precisely delimiting description of the group the term is intended to subsume.
An antecedentless pronoun is an example in the singular of the Ambigious
Here are two examples of the Ambiguous Collective fallacy:
"Last November, 77% of us voted in favor of term limits."
In this statement, who exactly are the "us"? The speaker wants to convey the idea that term limits are very widely supported, but if in fact the 77% refers only to those who voted, that subgroup may well be a quite small percentage of the total population.
"We need to train doctors to teach us how to get and stay healthy."
In this statement, who are the "we" and who are the "us"? Is the speaker
trying to promote socialized medicine by advocating government control of the medical schools? When he says "we need to" does he really mean "the government should"? And is the "us" merely a subtle way of saying "me"?
- [Amb] Amphiboly refers to ambiguity due to the grammatical construction of the premises. A statement is amphibolous when its meaning is indeterminate because of awkward word combinations and tricky phrasings. "Save Soap and Waste Paper" Croesus, the king of Lydia, was contemplating war with the kingdom of Persia. Being cautious, he consulted the Delphi, who told Croesus that "he would destroy a mighty kingdom." Delighted, he went to war - and was defeated by Cyrus. He survived and later complained to the Oracle. The prists of the Oracle answered that the Oracle was quite right, Croesus had destroyed a kingdom - his own! Amphibolous statements make dangerous premises.
- He assumes (implicitly) that I will
correct his mistaken assumptions.
- [Rel] Appeal to force. When one appeals to force or threat of force to cause acceptance of a conclusion. It is usually used when rational arguments fail. "Disagree with me and I'll take you straight to jail." "I'll remind the senator that his constituents will surely vote him out of office unless he concurs with his vote."
- "If government didn't exercise control over the manufacture,
distribution, price and sale of shoes we would all go barefoot!" If "shoes"
doesn't suit you, just substitute "police" or "fire protection" or "mail
delivery" or anything else the government claims to provide.
Nothing the government claims to provide cannot be provided in a more
humane, just, and economical manner by free associations of individual people.
- (From "Free To Choose" by Milton Friedman) What would you
think of someone who said, "I would like to have a cat provided it barked"?
Yet your statement that you favor a government provided it behaves as you
believe desirable is precisely equivalent. The biological laws that specify
the characteristics of cats are no more rigid than the political laws that
specify the behavior of government agencies once they are established. The way
the government behaves and the adverse consequences are not an accident, not a
result of some easily corrected human mistake, but a consequence of its
constitution in precisely the same way that a meow is related to the
constitution of a cat.
- False Dichotomy. Choosing to view a continuum as represented by only its extremities. It consists in dividing a range of options exhaustively into the two extremes and then insisting that a choice be made between one or the other extreme, without regard to any of the intervening alternatives. "Either you are with us, or you are with the terrorists." - George W. Bush
- Considering the actual utility while ignoring
the utility of alternatives. "Suppose it cost six francs to repair the damage,
and you say that the accident brings six francs to the glazier's trade - that it
encourages that trade to the amount of six francs - I grant it; I have not a word
to say against it; you reason justly. The glazier comes, performs his task,
receives his six francs, rubs Ms hands, and, in his heart, blesses the careless
child. All this is that which is seen. But if, on the other hand, you come to the
conclusion, as is too often the case, that it is a good thing to break windows,
that it causes money to circulate, and that the encouragement of industry in
general will be the result of it, you will oblige me to call out, "Stop there!
your theory is confined to that which is seen; it takes no account of that which
is not seen." -
That Which is Seen,
and That Which is Not Seen, by Frederic Bastiat, 1850 Fredric Bastiat, 1850
- [Rel] Hasty Generalization. Considering only a few cases, or only exceptional cases, and making an erroneous generalization from these limited examples. "Everyone on Skid Row was dirty and destitute and half-dead. Alcohol is obviously poison to man."
- [Rel] Compound or otherwise non-straightforward questions which cannot be answered appropriately with a simple "yes" or "no." They may presuppose a definite answer to an unasked prior question. "Do you still beat your wife?" "Did your sales increase as a result of your misleading advertising?" Another variation of this fallacy conjoins two questions and attempts to force an identical answer. "Are you for the Republicans and prosperity or not?" "Be a good boy and go to bed." The best way to handle such questions is to break them down into component parts. E.g. "I have never beat my wife, so your question is irrelevant." "I am for prosperity, but I'm no damn Republican." Parliamentary procedure does this with a motion to "divide the question."
- If someone comes up against a large bundle of particular facts, but has no general principles with which to integrate those particulars, and is not in the habit of thinking in principles, the multiplicity of facts will appear so complex to him that he will not be able to deal with the situation analytically. You will hear him say:
"This is too complex a situation to yield any easy solution!"
For him it is indeed too complex - he has no way to sort the facts, to
identify their distinguishing characteristics, and to grasp the fundamentals underlying them. Without integrating principles he just cannot cope. His solution will be an Ad Hoc solution that will fail to address more than a few of the particulars. He will manifest a Descriptive (rather than Analytical) intellectuality. (The descriptive person believes that his description IS an analysis.) He does not think in principles, but focuses his attention on the presentation of specific phenomena only.
"Unfortunately, no easy answers exist. The solution to the problem will
turn out to be as complex as the problem itself."
"That's a simplistic view of a complex situation."
Complexity does not make something unintelligible, any more than the
complexity of the symptoms of a disease make the cause of those symptoms unintelligible. What makes the phenomenon unintelligible is the attempt to analyze it without reference to fundamental principle - to a unifying cause.
Abstraction offers a method for thinking about complicated issues in a
precise way. By resorting to particularizing rather than generalizing, pragmatists are left floundering in a mire of complexity. The contention that principles are simplistic is a spurious one; it is only by means of principles that man is able to retain and make use of the vast storehouse of knowledge relevant to any given issue. Concretes by themselves are meaningless, and cannot even be retained for long; abstractions by themselves are vague or empty. But concretes illuminated by an abstraction acquire meaning, and thereby permanence in our minds; and abstractions illustrated by concretes acquire specificity, reality, the power to convince.
- [Amb] Actually two closely related fallacies. In one form the fallacy of composition is falsely ascribing the properties of the parts of a whole to the whole. "Every part of this machine is light in weight. Therefore the whole machine is light in weight." But a heavy machine could have a large number of light-weight parts. The second form of this fallacy consists of confusing the distributive and collective use of general terms. [Are there languages which make such a distinction?] "A bus uses more gas than a car. Therefore all buses use more gas than all cars." The premise is a (distributive) comparison of one bus to one car. The conclusion compares the (collective) use of all buses to all cars. Distributively, buses use more gas than cars. But collectively, cars use more gas because there are so many more of them. The reverse of the fallacy of composition is the fallacy of division.
- [Rel] Assuming that if something had not occurred one way,
it would never have occurred. "If it hadn't been for Columbus, America never would
have been discovered."
aka Fantasy Projection
- An attempt to impose his own
intellectual or moral context on another person by someone who has closed his mind to reality and manufactured his own fantasy, then expects others to share it and help him sustain it. He ignores the objective realities of the situation, concentrating instead on subjective perceptions that are false. "If you were terminally ill, you too would advocate life preservation."
"There are no atheists in foxholes." By naming her opinion in advance he
would make her unable to alter it.
Imposition of the Slave Mentality: "Aren't you thankful that they allow
this?" (I am expected to limit myself to the context of "their" allowables.)
The proper answer is, "No, I am resentful that they forbid other freedoms I
They have a six-inch knife and have stuck it four inches into me. Should I be thankful they have not shoved it in the final two inches? Or resentful that they have shoved it in four inches? (I am expected to accept their behavioral context and to judge my situation from within that context.)
- [For] The hypothetical syllogism "If A then B; B is false; Therefore A is false" is valid. It is called modus tollens, denying the consequent. It would be a mistake to deny the the antecedent A instead of the consequent B. This is the Fallacy of Denying the Antecedent. "If Sam buys the beer, then he's a nice guy; Sam didn't buy the beer; Therefore Sam is not a nice guy."
- (The Objectivist Newsletter, May 1963) "The doctrine of
determinism contains a central and insuperable contradiction - an
EPISTEMOLOGICAL contradiction - a contradiction implicit in any variety of
determinism, whether the alleged determining forces be physical,
psychological, environmental or divine. In fact, Man is neither omniscient nor
infallible. This means: (a) that he must work to ACHIEVE his knowledge, and
(b) that the mere presence of an idea inside his mind does not prove that the
idea is true; many ideas may enter a man's mind which are false. But if man
believes what he HAS to believe, if he is not free to test his beliefs against
reality and to validate or reject them - if the actions and content of his
mind are determined by factors that may or may not have anything to do with
reason, logic and reality - then he can never know if his conclusions are true
or false....But if this were true, no knowledge - no CONCEPTUAL knowledge -
would be possible to man. No theory could claim greater plausibility than any
other - including the theory of psychological determinism."
One of the catches to determinism is that you cannot argue with it. To
argue is to make an attempt to induce someone to alter the actions or content
of his mind. The determinist enters the argument with the claim that such
alteration is impossible - that he has no power to volitionally change his
state of consciousness. He says, and means literally, "My mind is made up -
don't confuse me with the facts!"
Biologists have tacitly assumed that when they have understood the
operation of each molecule in a nerve membrane, they will understand the
operation of the mind. But both the digital and the analog paradigms of
computation make it clear that this assumption is wrong. After all, a computer
is built from a completely known arrangement of devices whose operation is
understood in minute detail. Yet it is often impossible to prove that even a
simple computer program will calculate its desired result or, for that matter,
whether the computation will even terminate.
Wilder Penfield explored the brain with electrical probes. By stimulating
different parts of the brain he could cause a subject to turn his head, blink
his eyes, move his limbs and a host of other things. But though he could make
the patient's hand move he could never make the patient feel that he had
WILLED the hand to move. Penfield found that the effects of consciousness
could be selectively controlled by outside manipulation. But however much he
probed, he could not enter consciousness itself. He could not find the mind
and invade its autonomy.
The fundamental question of free will does not involve Man's physical
behavior but his psychological behavior. It concerns Man's ability to control
the functioning of his own mind.
On the Determinist premise, men are not merely unfit for freedom, they are
metaphysically incapable of it since they do not have fundamental control over
the choices made in their minds. Political issues become matters of pure
pragmatism: there is no right or wrong, but only effective or ineffective
techniques of social manipulation.
- The alteration of history by personal decree. This
is done by the sort of person who tries to rewrite history with his tongue.
- Define by using the Genus only.
- [Amb] This is the reverse of the fallacy of composition. It involves the same confusion between whole and parts, but reverses the direction of inference. "This machine is heavy, so each part must be heavy." "Corporation X is very important; Joe Blow works for corporation X; Therefore Joe Blow is important." "American Indians are disappearing; That man is an American Indian; Therefore that man is disappearing." "Riddle: Why do white sheep eat more than black sheep? A: Because there are more of them."
- A form of false dichotomy. Insists that all donuts be divided into two piles: large donuts and sugar donuts.
- Eclecticism consists of selecting the good parts from a set of ideas and discarding the bad parts. But this process implies that you already know how to do the selecting, and have a standard of judgment to use for evaluating the ideas.
If you in fact do, then there is no problem and eclecticism is a valid
intellectual process. But if you approach a set of ideas in a state of
ignorance then you are not intellectually equipped to pick and choose from
among them. You could not know whether what you accepted is true or false.
Herein lies the danger of eclecticism if you are going to pick and choose
you must already have enough knowledge to do the selecting.
- To emphasize one element of a set at the expense of other equally significant elements. Or to place emphasis on a spurious aspect of a situation. You see this when people react violently to comparatively
minor troubles but are seemingly unshaken by really serious ones. It is a sort of being at a loss for a proportionate emotional reactiona shivering at shadows.
- "Hey, mister, you better buy a bottle of my Elephant Repellent. If you don't buy it, the elephants will come into the neighborhood and trample you! My proof that this stuff really works is that there are no elephants around here." for "Elephant Repellent" substitute the word "Government" and for "elephants" substitute the word "crime" or "Russians" or "poverty" or "chaos" or anything else the government claims to prevent. Nothing the government claims to prevent cannot be prevented in a more humane, just, and economical manner by free associations of individual people.
- [Amb] alt Fallacy of Four Terms in the context of categorical syllogisms.
Many words have more than one meaning. If we use a word in two or more different ways, we are using that word equivocally. If this is done in an argument, we commit the fallacy of equivocation. "The end of a thing is its perfection; death is the end of life; hence, death is the perfection of life." This is fallacious because "end" is used in two different ways: 1) goal, and 2) final event. In the example these two meanings are confused. One special kind of equivocation are those using relative terms. "He must be a good man, because he is a good football player." Equivocation refers to ambiguity in the meaning of a particular word or phrase.
- [For] A standard-form categorical syllogism with two negative premises is invalid, and commits the fallacy of exclusive premises. In the first premise, all we know is the middle and predicate are wholly or partially excluded from each other. Similary, the second premise tells us the middle and subject are wholly or partially excluded from each other. This is too little information to draw a valid conclusion about a categorical relationship between the subject and predicate.
- Trying to make an idea of limited applicability extend in its coverage to the inclusion of an overly large range: "All human experience can be explained by a study of energy flows."
- [For] Assuming the existence of a member of a class solely on the basis a universal (All S is P; No S is P) proposition. If it is not explicitly asserted that a class has members, it is a mistake to assume that it does. For standard-form categorical syllogisms, two universal premises cannot validly yield a particular conclusion.
- Assuming that only one alternative exists in a given
situation, when in fact, a second and usually more fundamental alternative
- "Straw Man." Present a false description
of a position or an adversary and then base your repudiation on that description.
"Objectivism advocates infanticide, therefore Objectivism is evil." "Athiests are in league with the devil, therefore false and evil." "Anarchists are for chaos, lawlessness, and disorder, therefore a failed political philosophy." "Rebublicans hate the poor and the workers, so we must oppose them."
- [Rel] alt Non Causa Pro Causa
To mistake what is not the cause of a given effect for its real cause. Some aboriginal people beat drums during an eclipse, thinking it caused the sun to return. "Mrs. X suffered from a head cold, drank three bottles of WonderJuice, and recovered only two weeks later." One variation of this fallacy is called Post Hoc Ergo Propter Hoc, assuming causation from mere temporal precedence.
- (Karl Popper) A conjecture or hypothesis must be
accepted as true until such time as it is proven to be false.
Popper maintains that scientists approach the truth through what he calls
"conjecture and refutation." In actuality, scientists approach the truth not
through conjecture and refutation, but through conjecture and CONFIRMATION,
i.e. demonstration, by means of careful experiment, that a hypothesis
corresponds to the facts of reality.
Until the phenomenon is proven TRUE there is no obligation to base my
attitude toward it on the assumption that it MIGHT be true. If there were such
an obligation, then I would be obliged to give serious consideration to every
crackpot notion that has ever been put forward.
- Restrict a wide abstraction to a
narrow set of particulars and then conclude that an attribute of these
particulars must be definitive of the abstraction, thus negating the entire
principled structure underlying the abstraction.
A similar fallacy is that of equating opposites by substituting
nonessentials for their essential characteristics.
"They concluded that a free market, by its nature, leads to its own
destruction and they came to the grotesque contradiction of attempting to
preserve the freedom of the market by government controls; to preserve the
benefits of laissez-faire by abrogating it."
- (Against Self-Confidence) If you cannot directly refute
someone's principles, you strike indirectly with an attack on their confidence
in those principles. Question their certainty of the principles' validity:
"How can you be sure you're right?"
- Devoting a lot of time and energy to
solving problems that don't exist, such as figuring out ways to navigate on a
flat earth. Generalizing from a hypostatization. Looking for an easy way out
of a dilemma that does not exist.
Theology is a study with no answers because it has no subject matter.
- (Milton Friedman, Essays in Positive Economics) A scientific or explanatory model abstracts a "real world" phenomena by attempting to capture the most important elements and ignoring the less important elements. Thus, it is an error to criticize a model on the basis that its assumptions don't conform to reality. What matters in evaluating a model is whether it yields better predictions than other models for the pertinent range of phenomena. "Newton's formula for the acceleration due to gravity is wrong, since it assumes no air resistance." "Classical economic models are wrong, since they assume perfect competition, rational calculation of interests, etc." These are not valid objections, since these models are successful in predicting the phenomena within their purview.
- (Barbara Branden's lectures, Principles of
Efficient Thinking - lecture #4) a generalization subsuming no particulars.
- (The Virtue of Selfishness, chapter 10) Substituting
a particular concrete for the wider abstract class to which it belongs such
as using a specific ethics (e.g., altruism) for the wider abstraction
- Also called "maturation of probability" fallacy, this is the mistake of assuming that probabilities change as a result of previous trials. Dice don't remember what numbers were previously thrown. Coins cannot remember how many previous tosses came up "heads." If a fair coin comes up "heads" 5 times in a row, the probability is still .5 that heads will come up again. Many betting schemes (e.g. in roulette) are based on this fallacy.
- This consists of making comparative judgments
(usually of people's behavior) that are based not on any moral or ethical
principle but are made by reference to a government (invariably one's own
government). The consequence is to make a spurious distinction between two
people (or groups) who in fact manifest identical behavior.
Tom Clancy: "Terrorists don't relate to the people around them as being
real people. They see them as objects, and since they're only objects,
whatever happens to them is not important. Once I met a man who killed four
people and didn't bat an eye; but he cried like a baby when we told him his
cat died. People like that don't even understand why they get sent to prison;
they really don't understand. Those are the scary ones."
What Clancy cannot see is that any policeman or any soldier of any country
manifests exactly the same behavior that Clancy has condemned as terrorism.
William Buckley: "The Cold War is a part of the human condition for so long
as you have two social phenomena which we can pretty safely denominate as
constants. The first is a society that accepts what it sees as the historical
mandate to dominate other societies at least as persistently as microbes
seek out human organisms to infect. And the second phenomenon, of course, is
the coexistence of a society that is determined NOT to be dominated or have
its friends dominated."
Buckley does not realize that a Soviet analyst would make precisely the
same identification that Buckley has made, but with the roles reversed.
- If the government is not doing something about a
problem, then nothing can be done about it. Only the government can solve
aka Spurious Causation
- "The consumer will have to pay the bill for the oil spill."
"Scientists are responsible for the danger of nuclear war."
"The advance of modern medicine underlies the present population
"Henry Ford is responsible for air pollution."
"Taxpayers are forced to finance policies that many of them would oppose."
The taxpayer does not do the financing the government does. The statement
implies that the taxpayer is performing some positive action, when in fact he
is the passive victim.
These seem to be variants of the POST HOC fallacy. The selected element is
contributory but is certainly not a sufficient cause. An attempt is being made
to transfer blame onto someone who is only marginally (or not at all)
- This consists of demanding that an idea be proven over and
over again indefinitely before its validity is acceptable. (The name was
conceived while watching an infant throw her toy onto the floor over and over
and over again.) An open mind does not grant equal status to truth and
falsehood. Nor does it remain floating forever in a stagnant vacuum of
neutrality and uncertainty.
- Appealing to a person's feelings or prejudices, rather than his intellect, with a trite phrase designed to reinforce a subjective rather than objective view of a situation. If the homily is not accepted in answer to the situation, the next thing that will be done is to attack the person's character rather than answer his argument.
- [Rel] Instead of trying to disprove the truth of the assertion, one attacks the man who made the assertion. Personal character is irrelevant to the truth or falsehood of an argument. Even wicked people may sometimes argue correctly or tell the truth. "My opponent's contentions are wrong; he is a scoundrel, liar and a thief." "Floridation is bad because it was proposed by commies." This last is a variant called the Genetic Fallacy, which fallaciously argues that a proposal is bad because it is supported or was proposed by an evil collective.
- [Rel] Appealing to a person's beliefs or circumstances rather than the truth or falsity of the proposition. Asserting that the opponent ought to accept it because of his special circumstances. "You must be against the pill, because you're a Catholic." "Being an African-American, no doubt you support government affirmative action."
- You assume that your adversary is Ignorant, Incompetent, and/or
Inexperienced and then impose this context on the discussion. I almost always
encounter this from astrologers, who admonish me to "examine this before you
reject it!" They always assume I have not done so.
- [Rel] Appeal to Ignorance. When it is argued that a proposition is true simply because it has not been proved false, or false because it has not been proved true. "There must be ghosts (UFO's, deities, dragons) because no one has been able to prove there aren't any."
Assertions based on what we do NOT know: "No one knows precisely what would happen if a core was to melt down, so ... ." And the compounding of arbitrarily asserted possibilities. What could happen is what is possible. The burden of proof is on the skeptic to provide some specific reason to doubt a conclusion that all available evidence supports.
- People who do not look into the
future beyond the end of their nose also do not look into the past beyond
yesterday (and sometimes not even that far). If they did, they would readily
see that the previous implementation of their schemes was invariably a
failure. Not only do they fail to see that the scheme WOULD BE a failure, they
fail to see that it HAS BEEN a failure.
- "You are safer walking down a dark alley than
sitting in your living room with friends, because most murders are committed
in the victim's home by his acquaintances." This ignores the fact that most
people spend much more of their time at home than walking down alleys.
- [For] In a valid standard-form categorical syllogism, if a term is distributed in the conclusion it must also be distributed in a premise. The major term or the minor term may lack such distribution, giving two sub-fallacies: Illicit Process of the Major Term (Illicit Major) and Illicit Process of the Minor Term (Illicit Minor). "All dogs are mammels; No cats are dogs; Therefore no cats are mammals." is Illicit Major since mammals is undistributed in the premise but is distributed in the conclusion. "All communists are subversives; All communists are critics of the current administration; Therefore all critics of the current administration are subversives." is Illicit Minor.
- To insist on implementing something which is known to have failed. "What we need is government control of the economy!"
- (The Virtue of Selfishness, chapter 19) "Only the most degenerate, morally depraved, cretinous imbecile could fail to see the truth of my argument."
- [Rel] alt Irrelevant Conclusion
When an argument purporting to establish a particular conclusion is directed to proving a different conclusion. E.g. In a debate on the legalization of drugs, someone opposing might argue that drugs kill many kids and result in crack babies, etc. and are thus a threat to society. This is quite irrelevant to the issue of legalization, as the question concerns the best policy for alleviating the (undisputed) harms. If legalization would reduce the harm and expense compared to the present policy of prohibition, then horror stories are irrelevant. (One sympathetic judge complimented a young lawyer on his excellent speech and expressed the hope that he would some day find a case to which it actually applied.)
- Some subtle methods of media distortion: use of
emotionally loaded images, isolation of events from their historical context,
limitation of debate to "responsible" options, framing of dissident viewpoints
in ways that trivialize them, personification of complex realities (Saddam =
Iraq), objectification of persons ("collateral damage")
- Take a small, inconsequential effect and magnify it to
become all-encompassing in its supposed influence. These are people whose fear
of the snake in the grass is so great that they are unable to see the bear
that is about to eat them.
- [Rel] The fallacy committed when one appeals to pity for the sake of getting a conclusion accepted. Lawyers defending guilty clients have used this type of argument. "The poor defendant was abused in childhood ... "
- "Computers might be able to understand Chinese and think about numbers but cannot do the crucially human things, such as...." - and then follows their favorite human specialty - falling in love, having a sense of humor, etc. But as soon as an artificial intelligence simulation succeeds, a new "crucial" element is selected (the goalpost is moved). Thus the perpetrators of this fallacy will never have to admit to the existence of artificial intelligence.
- A type of false dichotomy that compares an actual policy with perfection rather than an actual alternative. "The view that now pervades much public policy economics implicitly presents the relevant choice as between an ideal norm and an existing 'imperfect' institutional arrangement. This nirvana approach differs considerably from a comparative institution approach in which the relevant choice is between alternative real institutional arrangements." (Harold Demsetz, 1969) A good defense is simply noting, "Nirvana is not an option."
- A statement (or question) that gives (or elicits) no
cognitively meaningful information: "Are you honest?" If he's honest, he'll
say 'Yes' - but if he's a liar, he'll say 'Yes' You learn nothing in either
- To consider only the immediate results of an action, ignoring the long-term effects.
- [Rel] alt Begging the Question; Circular Reasoning
Assuming as a premise for an argument that which you intend to prove. Two formulations can be sufficiently different to obscure the fact that one and the same proposition is used as both premis and conclusion. "She says that I am her only love. She must be telling the truth, because no one would lie to their only love." Alternatively, a chain of reasoning can "loop" back, i.e. be mutually dependent. "Shakespeare is a greater writer than Robbins because people with good taste in literature prefer Shakespeare. How do I know who has good taste? Clearly people with good literary taste are those who prefer Shakespeare to Robbins."
- An attempt to subsume something into a frame-of-reference
that is too small to incorporate the thing. "You call me a name so you don't have to see me - you just see the name that you call me."
- [Rel] Bandwagon Fallacy. The attempt to win popular assent to a conclusion by arousing the feelings and enthusiasms of the multitudes. This is a favorite of advertisers, who surround their products with pretty models and various icons of popular approval. "Lying on your resume is OK since everybody does it." "All societies require military service. We are a society. Therefore we should require military service."
- [Rel] Falsely assuming that an earlier event caused a later event for the mere reason that it happened earlier. "Over 95% of all heroin addicts in the US have previously used marijuana. Therefore marijuana leads to heroin." (Substituting "milk" for "marijuana" neatly exposes the preceding.) This fallacy is a variation of the False Cause fallacy.
- (Temporal nullification of a previous
phenomenon) Unless you can specify the exact moment I made a certain
statement, then you must concede my insistence that I never made that
statement. "When did I say that?" For a clever (and bewildering) retort
reply: "About 20 minutes past 2 on Thursday afternoon."
- Here the speaker assumes omniscience in respect to the
subject under consideration. He assumes also that he speaks for the entire
human race. "We don't know what life is" (or insanity, intelligence, etc). "We
can't conceive of personal death." Any attempt to refute this fallacy will
usually elicit its corollary, The Falsifiability Syndrome.
- Having made a brief reference to a phenomenon,
you later assert that the phenomenon has now been fully explained.
- Richard Feynman: "Many years ago I awoke in
the dead of night in a cold sweat, with the certain knowledge that a close
relative had suddenly died. I was so gripped with the haunting intensity of
the experience that I was afraid to place a long-distance phone call, for fear
that the relative would trip over the telephone cord (or something) and make
the experience a self-fulfilling prophecy. In fact, the relative is alive and
well, and whatever psychological roots the experience may have, it was not a
reflection of an imminent event in the real world. After my experience I did
not write a letter to an institute of parapsychology relating a compelling
predictive dream which was not borne out by reality. That is not a memorable
letter. But had the death I dreamt actually occurred, such a letter would have
been marked down as evidence for precognition. The hits are recorded, the
misses are not. Thus human nature unconsciously conspires to produce a biased
reporting of the frequency of such events. If enough independent phenomena are
studied and correlations sought, some will of course be found. If we know only
the coincidences and not the unsuccessful trials, we might believe that an
important finding has been made. Actually, it is only what statisticians call
the fallacy of the enumeration of favorable circumstances."
- (What Proves Too Much, Proves Nothing) Another common logical error committed by drunk-driving prohibitionists is to present arguments that clearly prove too much. That is, in their attempt to single out and vilify drunk drivers as absolute scum of the Earth, they draw conclusions that imply absurd consequences if they were taken to their logical conclusion. For example, prohibitionists often defend prohibition in the following manner:
"Am I to understand that you support WAITING until someone DIES to object to another's irresponsibility? I find that simplistic, foolish, and unacceptable. The reason I do is that the life lost is irreplaceable!"
The problem with this sort of argument is that it proves far, far too much (in addition to making an irrelevant appeal to emotion). For, this argument could be extended to all aspects of human life, and virtually everything people do would be punished by ruthless laws - regardless of whether people actually hurt anyone. This argument would apply, for example, to people who drive without their glasses (and who currently only get a minor ticket if pulled over, instead of a stay in jail), people who text on their phones while driving, people who ride their bikes with bad brakes, people who work with flammable liquids around other people, et cetera ad infinitum. In fact, if the argument were taken to its logical conclusion, every single human action would be punished by draconian laws and jack-booted policemen, since people can, and do, negligently kill other people in virtually every situation where men encounter one another on this planet. The argument does not give us any reason why we ought to single out drunk drivers to punish so ruthlessly, when we let other negligent people totally off the hook - like people who drive without their glasses. (from A Primer on Logic For Drunk Driving Prohibitionists by Mark R. Crovelli
- (The Objectivist Newsletter, April 1963) "Proving
the non-existence of that for which no evidence of any kind exists. Proof,
logic, reason, thinking, knowledge pertain to and deal only with that which
exists. They cannot be applied to that which does not exist. Nothing can be
relevant or applicable to the non-existent. The non-existent is nothing. A
positive statement, based on facts that have been erroneously interpreted, can
be refuted - by means of exposing the errors in the interpretation of the
facts. Such refutation is the disproving of a positive, not the proving of a
negative.... Rational demonstration is necessary to support even the claim
that a thing is possible. It is a breach of logic to assert that that which
has not been proven to be impossible is, therefore, possible. An absence does
not constitute proof of anything. Nothing can be derived from nothing."
If I say, "Anything is possible" I must admit the possibility that the
statement I just made is false. (See Self Exclusion)
Doubt must always be specific, and can only exist in contrast to things
which cannot properly be doubted.
- Regarding a possible effect as being a
certainty, when making an evaluation of a cause. This has two significant
variants: Reification of the Improbable, and
Reification of the Existent,
which consists of basing one's criticism of a scheme on the observation that
one possible outcome of that scheme might lead to a state of affairs that
already exists under the present circumstances.
- To try to make a phenomenon appear good, by
comparing it with a worse phenomenon, or to try to make a phenomenon appear
bad, by comparing it with a better phenomenon.
Consider junkfood. A very nutritionally-conscious person has a rather low
opinion of junkfood. But what would be your attitude toward a greasy hamburger
if you hadn't eaten for three or four days? You can malign junkfood because
your nutritional standards are high enough to permit you to do so. But an
Ethiopian would like nothing better than to have access to MacDonald's,
Hardee's or Wendy's and, in fact, such access would be the best thing that
could happen to the Ethiopian. Because you have alternatives that the
Ethiopian does not have, he is in a position of relative privation when
compared to you.
In just the same way, the people who labored in sweatshops at the turn of
the century were in a state of relative privation when compared to you.
Because your alternatives are different (and much better), the sweatshop seems
to you to be an abomination, but in fact the sweatshop was immensly preferable
to the alternatives available to them.
"Eat your carrots! Just think of all the starving children in China."
"I used to lament having no shoes - until I met a man who had no feet."
The real danger from this last example of the fallacy is that if people
believe that their own situation really is ameliorated by such a comparison,
they will naturally conclude that their own situation can, in practice,
actually BE ameliorated by MAKING somebody else worse off!
- An interview with a young woman who had seven
children - all of them "crack babies":
Interviewer: "Didn't you ever think about the effect your drug use was
having on your children?"
Woman: "Yeah, that thought entered my mind now and then. Whenever it did, I
got high so that I wouldn't have to think about it."
The cause (drug use) has an effect (remorse). She invokes the cause in
order to eliminate the effect. Thus the effect acts retrogressively to induce
further implementation of the cause.
- "The death rate among American soldiers in Vietnam
was lower than among the general population." But the soldiers in Vietnam were
young and healthy. You are comparing them with a data base including non-young
and non-healthy people.
- This is a form of the Stolen Concept fallacy. It denies
itself. "Nothing makes any difference." (including this statement?) "Music is
the only genuine form of communication." (but this statement, meant to be a
communication, is not music) "True knowledge is impossible to man." (but this
statement is meant to be knowledge) "There are no absolutes." (except this
one, of course) "Words have no validity." To say that "one should not make
judgments" is to make a judgment.
"There are questions whose truth or untruth cannot be decided by men; all
the supreme questions, all the supreme problems of value are beyond human
comprehension." .... Nietzsche
David Kelley: "To assert 'what is known depends on the knowledge of it' is
to offer that very thesis as something known, and therefore as a statement
that subsumes itself. But this is manifestly not what the proponent of the
thesis intends. That facts depend on our belief in them, he implies, is
objectively true, a fact of reality about consciousness and its objects, made
true by the nature of things, not by his believing it. Otherwise he would have
to allow that objectivity is a fact for the objectivist. He would have to
allow that the primacy of consciousness is both true, because he believes it,
and false, because the objectivist denies it. [But the Marxist multi-logic
dialectic does indeed assert this very notion.] To avoid this, he must assert
that the objectivist is wrong, which means asserting the primacy of
consciousness as a fact he himself did not create. He thereby contradicts his
own thesis. It is an inner or performative contradiction, like that of the
person who denies the axiom of action - the denial itself being an action."
- Agglomerating several different superficial aspects of a
subject, in hopes that the resulting verbal structure will be comprehensible.
- Consent to what? Just what is it I consent to when I do NOT vote? To the
policies of Bush? To the policies of Clinton? To the policies of Marrou? To
the policies of all those whose principled disagreement with the electoral
system precludes their participation in it?
The process of implication contains a causal relationship. For one thing to
imply another thing, there must be a causal sequence between the two things.
People who make the assertion "silence implies consent" never propose any
chain of logical connection between the silence and the consent. Precisely how
does consent arise from silence? How can dead men be said to consent to
If my silence does imply consent, then how far does that implication reach?
Am I considered to consent to all things about which I am silent? Even those
about which I am completely ignorant? To the fact that someone in Calcutta
beats his wife? If I must express disapproval of all things with which I do
NOT consent, for fear of reproach resulting from my silence about any of them,
there would not be sufficient hours in the day for such a plethora of denials.
- When a disputant allows himself to be
sidetracked by irrelevancies, ignoring his opponent's logic and evidence. He
cannot grasp the whole of the issue - or the principle underlying it - so he
focuses on some small part (usually just one word) and directs his rebuttal to
an attack on that tiny bit which is all he can perceive. "What do you mean by
------?" Where ------ is any word included in your presentation, usually a
quite ordinary word which your opponent uses without any difficulty in other
contexts. He views things through his specialized eyes, extracts a part of the
truth and refuses to see more, sometimes quoting your least significant
statements, in order to make it appear that you have said nothing better.
Some Ad Hominem arguments probably have the same source: He can't see your
ideas so he directs his rebuttal at your person. Or will simply start talking
about something he CAN understand - the result being a jarring change-of-
subject in the discussion.
He seizes upon one instance and constructs a generalization from it:
Observing that I don't like clams, he concludes that I have an aversion to sea
food in general. She sees something happen once or twice and concludes that it
is a regularly-occuring phenomenon.
These responses are not consciously deliberated, but result from his
inability to perceive the focal idea of the discussion. His only alternative
to one of these responses would be bovine immobility unless he possessed a
sufficient degree of intellectual acumen to realize his lack of comprehension,
and a sufficient degree of self-esteem to admit to it.
- (The Objectivist Newsletter, Jan 1963) Using a concept
while ignoring, contradicting or denying the validity of the concepts on which
it logically and genetically depends. "All property is theft." "The axioms of
logic are arbitrary." (something is arbitrary only in distinction to that
which is logically necessary.) "All that exists is change and motion." (change
is possible only to an existent entity) "You cannot prove that you exist."
(proof presupposes existence) "Acceptance of reason is an act of faith."
(faith has meaning only in contradistinction to reason)
- "During the economic crisis, millions of people
were thrown out of work." Who threw them out? The first answer to this would
probably be, "their employers." The statment certainly invites the readers to
infer this. But in fact, government, which destroyed the unfortunate workers'
industries by means of taxation and regulation, is the causal agent that the
passive construction of the statement suppresses or banishes from the mind.
Dehumanization of the Action: "During the first two years of Garcia's
administration, the economy grew rapidly." This sentence establishes a strong,
though implicit, causal connection between Garcia's interventionist programs
and good economic news. "But inflation escaped the government's control and
the economy soon began to contract." Economic developments are now pictured as
things with their own, non-human, principles of action. They are not caused by
anything that humans like Garcia do, but proceed on their own way.
- (Atlas Shrugged Part3 Chap8 pg1076)
Someone so far removed from your frame of reference that he is psychologically
- People who don't think in principles will not be able to see the principles underlying a philosophy. Usually, all they will be able to see is the behavior of individuals who call themselves adherents of that philosophy.
- "You, too" or "You, also." An attempt to discredit the opponent's position by exposing his failure to act consistently in accordance with that position; it attempts to show that a criticism or objection applies equally to the person making it. It is type of ad hominem - circumstantial.
- [For] In a valid standard-form categorical syllogism, the middle term must be distributed in at least one premis. An argument which, when reduced to standard-form categorical syllogism, fails this rule commits the fallacy of the undistributed middle. The conclusion asserts a connection between the subject and the predicate. To connect via a middle term with two premises requires at least one premise to refer to all of the middle, i.e. the middle must be distributed.
- (from James P. Hogan)
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts." - Bertrand
Why didn't he put "I think" at the end of it? By omitting the "doubt-
qualifier" Russell is unintentionally describing his own attitude.
- (The Objectivist Newsletter, Jan 1963) "That which, by its
nature, cannot be known. To claim it unknowable, one must first know not only
that it exists but have enough knowledge of it to justify the assertion. The
assertion and the justification are then in contradiction. To make the
assertion without justification is an irrationalism."
Branden's argument implies that the unknowable must be a particular,
specifiable entity. I maintain that it can be merely an aspect of existence
that consciousness cannot perceive.
To assert that all things CAN be known is to imply that existence is
subsumed by consciousness.
I claim that there are unknowables. Not any particular, specifiable
unknowable items (for that would indeed be the contradiction noted above), but
merely aspects of reality that are unperceiveable. (You cannot simultaneously
perceive both sides of your cat.) My justification for this assertion is the
primacy of existence over consciousness.
Thus Quantum Indeterminacy is a genuine phenomenon. It is the closest we
can come to specifying an aspect of reality that is unknowable: the
simultaneous perception of position and momentum.
- Generating dissimilar images from similar concepts.
Certain kinds of crops, such as corn, are "harvested", but other kinds, such
as trees, are "slashed" or "devastated". Who would forbid farmers to "harvest"
a crop of beets? But who would willingly allow men armed with chainsaws to
"devastate" the ecology?
- [Rel] Appeal to Authority. The attempt to win assent to an argument by appealing to people's respect for the famous. This type of argument may or may not be fallacious depending on the expertise of the person in the field in question and the relative knowledge of the debaters. If the debaters are experts themselves, then appeal to another expert is worthless as evidence. Most commonly, an authority is appealed to for testimony outside his/her field, e.g. Albert Einstein on politics, or Joe Montana on retail shopping. The relevant question is: Whose authority? If an issue is to be resolved by such an appeal, the authority must be one recognized by both parties.
- If you take the old tongue-twister: "How much wood
could a woodchuck chuck if a woodchuck could chuck wood?" and make a slight
homonymous substitution: "How much would could a wouldchuck chuck if a
wouldchuck could chuck would?" you arrive at a description of a certain kind
of dissertation made by people who are trying to "prove" an idea for which
they have no factual corroboration.
This is a description of much of scientific belief before the time of
Galileo. For instance, it was believed that if you dropped a 5-pound rock and
a 10-pound rock simultaneously, the 10-pounder WOULD hit the ground first
because, being heavier, it WOULD therefore be pulled down harder and WOULD
therefore travel faster. Notice the use of the word "would" in those
statements. This expression of conditional probability is chucked around as
though it were an assertion of factual reality. Implicit to such statements is
the assumption that what seems plausible is therefore true and requires no
I became acutely aware of this "Wouldchuck" argument while reading the
Tannehills' book, "The Market For Liberty." The entirety of Part2, which sets
forth in detail their view of a free-market society, consists of the
Wouldchuck argument. Here is a typical example:
"This insurance would be sold to the contracting parties at the time the
contract was ratified. Before an insurance company would indemnify its insured
for loss in a case of broken contract, the matter would have to be submitted
to arbitration as provided in the contract. For this reason there would be a
close link between the business of contract insurance and the business of
Sounds plausible, doesn't it? Yes... BUT, no proof of these conjectures is
offered. They are nothing more than unsubstantiated hypostatizations.
The proponent of a program, through the use of this argument, can
articulate a comprehensive framework within which the implementation of his program seems undeniably plausible. But if the framework itself has no other foundation than this WouldChuck supposition, the whole scheme rests on a very shaky basis.
E-mail me at: email@example.com. Revised 1/25/15 History.