Evidential

Evidential fallacies arise from a misunderstanding of the nature of evidence, or from a disparity in the strength of one’s belief/disbelief and the degree of evidence supporting that belief/disbelief.

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Witness chain:

Definition Example
When a witness attempts to bolster their own testimony by claiming, with no independent substantiation, that there were other witnesses. I saw a ghost 5 years ago, and my uncle who died last year told me he also saw it!
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Track-record reset:

Evidential Fallacy
Definition Example
When, for every new question in a particular domain, the inductive evidence from relevant past experience is ignored. Wake up, Dear! Something’s banging on the trash cans again. I know that for the hundreds of other times you’ve checked, it’s only been cats, but could you please go out and make sure it isn’t zombies this time?
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Piggy-back assumption:

Evidential Fallacy
Definition Example
When one assumption is connected to a second assumption in a non-contingent way, then the 1st assumption is deemed justified by evidence for the second assumption. I’ve told you that I’m a CIA agent from Boston. Here’s my driver’s license showing a Boston address. That should make it clear that I work for the CIA.
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Impotent logical space:

Definition Example
When every possible outcome is encompassed by a single theorized cause, thereby rendering it either redundant to another explanatory theory, or non-existent. We have only blurry photo evidence for the existence of alien space ships, but that’s only because the aliens have technology that prevent our cameras from functioning properly.
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Mental cause fallacy:

Definition Example
When the effects of a belief in a thing are assumed to be evidence for the existence of that thing. Those who believe they are intelligent, out-perform on IQ tests those who think they are not intelligent. Therefore they are more intelligent.
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Denying a remote hypothetical:

Definition Example
When a hypothetical introduced to assess the coherency of a concept is rejected on grounds it is rare or improbable. I don’t need to assess my moral code against your scenario of having to choose between killing my child or my father or letting them both starve since such a dilemma has probably never actually occurred in real life.
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Bare assertion fallacy:

Definition Example
When a premise is introduced as a conclusion without substantiation. My father Is 3 meters tall. Your father is only 1.5 meters tall. Therefore my father is taller than your father.
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Denial of the epistemic gradient:

Definition Example
When semantic resolution is decreased by invoking artificially binary or granular epistemic categories. Either you believe in space aliens or you don’t. You need to make up your mind.
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Imposed Disbelief

Definition Example
When the lack of belief in X is construed as disbelief in X. Where’s your evidence for your belief that there are no unicorns? Your faith in the lack of unicorns is no different from my faith in the existence of unicorns.
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All or nothing fallacy:

Definition Example
When it is suggested or implied that one must believe all or nothing of a particular set of beliefs. Saint Nicholas clearly existed, so why are you suggesting he does not descend chimneys in a red suit Christmas eve?
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Demanding a mechanism:

Evidential Fallacy
Definition Example
When overwhelming evidence for a phenomenon is rejected on the grounds that the causal mechanism is not known or understood. Scientists still can’t fully explain how and why lightning occurs. Therefore, I am not obligated to assume that the cause is electromagnetic.
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Bottom-up condemnation:

Definition Example
An argument of the following form. “a” has the negative quality “x” and belongs to the group “A”. Therefore “A’s have “x”. My neighbor is a banker, and is a jerk. Therefore, bankers are jerks.
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Bottom-up justification:

Definition Example
An argument of the following form. “a” has the positive quality “x” and belongs to the group “A”. Therefore “A”s have “x”. My neighbor is a banker, and a really nice guy. Therefore, bankers are nice guys.
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Top-down condemnation:

Definition Example
An argument of the following form. Group “A” has negative quality “x” and member “a” belongs to group “A”. Therefore member “a” has negative quality “x” Bankers are jerks, and because my neighbor is a banker, he must be a jerk.
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Top-down justification:

Definition Example
An argument of the following form. Group “A” has positive quality “x” and member “a” belongs to group “A”. Therefore member “a” has negative quality “x”. Bankers are nice people, and since my neighbor is a banker, he must be a nice guy.
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Faulty generalization:

Definition Example
When a conclusion based on induction is unwarranted by the degree of relevant evidence or ignores information that warrants an exception. He and his 4 brothers are bald, so his sister must also be bald.
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Special pleading:

Definition Example
When a proponent of a position attempts to introduce an exemption to a generally accepted rule or principle without justifying the exemption. Prayer works in spite of appearances that it doesn’t because you can’t subject it to the tools of science.
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Moving the goalpost:

Definition Example
When the evidence presented by A to meet an initial standard of evidence is dismissed by B, and some greater standard of evidence is then imposed by A on B. You’re so weak you can’t even lift this box! … All right, I see you can lift that box, but you’re still weak. I bet you can’t lift this bigger box!
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Cherry picking:

Definition Example
When individual cases or data are emphasized to confirm a particular position, while other cases or data that may contradict that position are ignored. I found 2 statistical studies that conclude violent video games do not actually increase violence among children. That’s proof enough for me!
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Proof by example:

Definition Example
When examples are offered as proof of a more universal proposition. This apple is red, so all apples must be red.
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Argument from fallacy:

Evidential Fallacy
Definition Example
When it is suggested that, if an argument for some conclusion is fallacious, then that conclusion is false. Tom told me that, because all Cubans are human, and I am a human, therefore I am a Cuban. His argument is invalid, and therefore I am not a Cuban.
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Sharpshooter fallacy:

Definition Example
When a precise target is chosen only after a vague prediction or speculation is made. Last year, the governor promised to stimulate the economy during his term, and you will note that this year there has been an increase of 2,000 jobs in the service industry.
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Hasty generalization:

Definition Example
When a conclusion is made about a group when there are insufficient statistics or an insufficient sample size. I drove through the town and counted 20 residents, all of them women. The town probably has only female residents.
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Chronological snobbery:

Definition Example
When a conclusion is deemed incorrect because it was commonly held in an era when something else that was clearly false was also commonly held. Why must we accept medieval art as having any value when it emerged from the same period in which people burned witches and believed in fairies?
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Argumentum ad populum:

Definition Example
When a conclusion is claimed to be true because many people believe it to be true. Nearly everyone believes chicken soup cures a cold, so how can you say it’s not true?
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Argument from silence:

Evidential Fallacy
Definition Example
When a conclusion is deemed true based on the lack of opposition. Because my opponent failed to address my point, my point is validated.
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Absence of evidence fallacy:

Evidential Fallacy
Definition Example
When it is argued that finding no evidence for something is no evidence for the absence of that thing. The fact that you did not see me at your birthday party does not mean I was not there!
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Redeeming illogic with evidence:

Evidential Fallacy
Definition Example
When a proponent of a concept demonstrated to be logically impossible continues to offer evidence for that concept. I have a golden square triangle instead of a heart beating in my chest, and I have the lab analysis to prove it.
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Argument from ignorance:

Evidential Fallacy
Definition Example
When it is sugggested that something is true because it has not been proven false, or false because it has not been proven to be true. Fairies must exist since we’ve seen no definitive evidence falsifying their existence.
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Appeal to tradition:

Definition Example
When a claim is deemed true on the basis that it has a long-standing tradition behind it. Polygamy is wrong because marriage here in our country has long been only between one man and one women.
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Wishful thinking:

Definition Example
When a position is encouraged based on what might be pleasing to imagine, rather than based on evidence or reason. If there were no life after death, then this life would be rather meaningless, and so I choose to believe we have an eternal soul.
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Tu quoque:

Definition Example
When it is assumed that, if one wrong has been committed, another wrong will remove its culpability. I admit to stretching the truth a bit, but you and everyone else tells a white lie from time to time. You can’t judge me.
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Association fallacy:

Definition Example
When a claim is deemed true or untrue based on an association with some irrelevant element. Jane is an exceptional pianist, and also pretty. Therefore, all pianists are pretty.
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Appeal to consequences:

Definition Example
When it is assumed that the positive/negative consequences of a claim, to some degree, reflect the truth/falsehood of that claim. If a virus erased my hard-drive, I’d loose all my work documents. So it can’t possibly happen.
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Appeal to authority:

Definition Example
When a claim is deemed true because of the position, authority or esteem of the person asserting it. My sociology professor says globalization has had a net negative effect on humanity, so it is obviously true.
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Appeal to accomplishment:

Definition Example
When an claim is deemed true based on the accomplishments of its sponsor. Isaac Newton had an immense impact on science, so there must have been some value in his later work in alchemy.
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Perfect solution fallacy:

Definition Example
When it is assumed that a perfect solution must exist and/or that a solution should be rejected because some part of the problem would still exist after it has been implemented. But, Dad! Driving the family station wagon to work and school is not going to be nearly as cool as driving around in the Mustang I crashed!
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Naturalistic fallacy:

Definition Example
When it is claimed that, if something is natural, pleasant, or popular, then it is good or right. I know I’m in love with a bank robber. But how could could it be wrong if it feels so right?
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Circular cause and consequence:

Definition Example
When the consequence of the phenomenon is said to be an unavoidable cause of the phenomenon when the truth may be otherwise. My music CD is not popular because people are not listening to it. And people are not listening to it because it is not popular. If they would only listen to it, it would become popular.
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