Logical Fallacies 1

[Praxeas]

What follows are some common Logical Fallacies seen on this board or others like it.

What is a Fallacy?
In order to understand what a fallacy is, one must understand what an argument is. Very briefly, an argument consists of one or more premises and one conclusion. A premise is a statement (a sentence that is either true or false) that is offered in support of the claim being made, which is the conclusion (which is also a sentence that is either true or false).

There are two main types of arguments: deductive and inductive. A deductive argument is an argument such that the premises provide (or appear to provide) complete support for the conclusion. An inductive argument is an argument such that the premises provide (or appear to provide) some degree of support (but less than complete support) for the conclusion. If the premises actually provide the required degree of support for the conclusion, then the argument is a good one. A good deductive argument is known as a valid argument and is such that if all its premises are true, then its conclusion must be true. If all the argument is valid and actually has all true premises, then it is known as a sound argument. If it is invalid or has one or more false premises, it will be unsound. A good inductive argument is known as a strong (or "cogent") inductive argument. It is such that if the premises are true, the conclusion is likely to be true.

A fallacy is, very generally, an error in reasoning. This differs from a factual error, which is simply being wrong about the facts. To be more specific, a fallacy is an "argument" in which the premises given for the conclusion do not provide the needed degree of support. A deductive fallacy is a deductive argument that is invalid (it is such that it could have all true premises and still have a false conclusion). An inductive fallacy is less formal than a deductive fallacy. They are simply "arguments" which appear to be inductive arguments, but the premises do not provided enough support for the conclusion. In such cases, even if the premises were true, the conclusion would not be more likely to be true.
http://www.thecaptainkirkpage.com/kirklogic.html

[Praxeas]

False Delimma
DEFINITION: A limited number of options (usually two) is given, while in reality there are more options. A false dilemma is an illegitimate use of the "or" operator.
Putting issues or opinions into "black or white" terms is a common instance of this fallacy.

Argument from Silence / Argument from Ignorance (argumentum ad ignorantiam)
DEFINITION: Arguments of this form assume that since something has not been proven false, it is therefore true. Conversely, such an argument may assume that since something has not been proven true, it is therefore false. (This is a special case of a false dilemma, since it assumes that all propositions must either be known to be true or known to be false.) As Davis writes, "Lack of proof is not proof."

Shifting the Burden of Proof
DEFINITION: The burden of proof is always on the person asserting something. Shifting the burden of proof, a special case of Argumentum ad Ignorantiam, is the fallacy of putting the burden of proof on the person who denies or questions the assertion. The source of the fallacy is the assumption that something is true unless proven otherwise

Complex Question / Fallacy of interrogation / Fallacy of presupposition
DEFINITION: Two otherwise unrelated points are conjoined and treated as a single proposition. The reader is expected to accept or reject both together, when in reality one is acceptable while the other is not. A complex question is an illegitimate use of the "and" operator.
EXAMPLE: "Do you agree that Picard is British and that Scotty is inferior?"
EXAMPLE (#2): "Have you stopped ripping on Picard?" (This asks two questions: Did you rip on Picard, and did you stop?)
PROOF: Identify the two propositions illegitimately conjoined and/or show that believing one does not mean that you have to believe the other.

Prejudicial Language
DEFINITION: Loaded or emotive terms are used to attach value or moral goodness to believing the proposition.
EXAMPLE (italics indicate the prejudicial language): "Reasonable Picard fans agree that 'Generations' is a great movie, and only the Kirk fanatics would disagree."
PROOF: Identify the prejudicial terms used. Such as in the example, show that disagreeing with the conclusion does not make a person "fanatical" or "unreasonable".

Appeal to Popularity (argumentum ad populum)
DEFINITION: These are also known as Appealing to the Gallery, or Appealing to the People. You commit this fallacy if you attempt to win acceptance of an assertion by appealing to a large group of people. This form of fallacy is often characterized by emotive language.
The Appeal to Popularity has the following form:
1. Most people approve of X (have favorable emotions towards X).
2. Therefore X is true.

Appeal to Emotion
DEFINITION: An Appeal to Emotion is a fallacy with the following structure:
1. Favorable emotions are associated with X.
2. Therefore, X is true.
This fallacy is committed when someone manipulates peoples' emotions in order to get them to accept a claim as being true. More formally, this sort of "reasoning" involves the substitution of various means of producing strong emotions in place of evidence for a claim. If the favorable emotions associated with X influence the person to accept X as true because they "feel good about X," then he has fallen prey to the fallacy.
This sort of "reasoning" is very common in politics and it serves as the basis for a large portion of modern advertising. Most political speeches are aimed at generating feelings in people so that these feelings will get them to vote or act a certain way. in the case of advertising, the commercials are aimed at evoking emotions that will influence people to buy certain products. In most cases, such speeches and commercials are notoriously free of real evidence.
This sort of "reasoning" is quite evidently fallacious. It is fallacious because using various tactics to incite emotions in people does not serve as evidence for a claim. For example, if a person were able to inspire in a person an incredible hatred of the claim that 1+1 = 2 and then inspired the person to love the claim that 1+1 = 3, it would hardly follow that the claim that 1+1 = 3 would be adequately supported.

[Praxeas]

Appeal to Belief
DEFINITION: Appeal to Belief is a fallacy that has this general pattern:
1. Most people believe that a claim, X, is true.
2. Therefore X is true.
This line of "reasoning" is fallacious because the fact that many people believe a claim does not, in general, serve as evidence that the claim is true.

Appeal To Numbers (Argumentum ad numerum)
DEFINITION: This fallacy is closely related to the argumentum ad populum. It consists of asserting that the more people who support or believe a proposition, the more likely it is that that proposition is correct.
EXAMPLE: "Everyone says that Kirk said 'Beam me up, Scotty' all the time on Star Trek. Therefore it's a fact."
PROOF: Identify the proposition and point out that just because many people believe a proposition to be true, does not mean the proposition IS true

Ad Hominem - Attacking the Person (argumentum ad hominem)
DEFINITION: The person presenting an argument is attacked instead of the argument itself. This takes many forms. For example, the person's character, nationality or religion may be attacked. Alternatively, it may be pointed out that a person stands to gain from a favourable outcome. Or, finally, a person may be attacked by association, or by the company he keeps.

Translated from Latin to English, "Ad Hominem" means "against the man" or "against the person."
An Ad Hominem is a general category of fallacies in which a claim or argument is rejected on the basis of some irrelevant fact about the author of or the person presenting the claim or argument. Typically, this fallacy involves two steps. First, an attack against the character of person making the claim, her circumstances, or her actions is made (or the character, circumstances, or actions of the person reporting the claim). Second, this attack is taken to be evidence against the claim or argument the person in question is making (or presenting). This type of "argument" has the following form:
1. Person A makes claim X.
2. Person B makes an attack on person A.
3. Therefore A's claim is false.

Ad Hominem (abusive)
Instead of attacking an assertion, the argument attacks the person who made the assertion.
EXAMPLE: "You think Kirk is better because you are just stupid."

Ad Hominem (tu quoque)
DEFINITION: This form of attack on the person notes that a person does not practise what he preaches. This fallacy is committed when it is concluded that a person's claim is false because 1) it is inconsistent with something else a person has said or 2) what a person says is inconsistent with her actions. This type of "argument" has the following form:
1. Person A makes claim X.
2. Person B asserts that A's actions or past claims are inconsistent with the truth of claim X.
3. Therefore X is false.

Poisoning The Well
DEFINITION: Another variant of Ad Hominem Circumstantial. This sort of "reasoning" involves trying to discredit what a person might later claim by presenting unfavorable information (be it true or false) about the person. This "argument" has the following form:
Unfavorable information (be it true or false) about person A is presented.
Therefore any claims person A makes will be false.[FONT=Times New Roman

Appeal to Authority (argumentum ad verecundiam)
DEFINITION: While sometimes it may be appropriate to cite an authority to support a point, often it is not.
An Appeal to Authority is a fallacy with the following form:
1. Person A is (claimed to be) an authority on subject S.
2. Person A makes claim C about subject S.
3. Therefore, C is true.
This fallacy is committed when the person in question is not a legitimate authority on the subject. More formally, if person A is not qualified to make reliable claims in subject S, then the argument will be fallacious.
This sort of reasoning is fallacious when the person in question is not an expert. In such cases the reasoning is flawed because the fact that an unqualified person makes a claim does not provide any justification for the claim. The claim could be true, but the fact that an unqualified person made the claim does not provide any rational reason to accept the claim as true.

Converse Accident / Sweeping Generalization / Dicto Simpliciter
DEFINITION: An exception to a generalization is applied to cases where the generalization should apply

[BeenThinkin]

Originally Posted by Praxeas

Appeal to Belief
DEFINITION: Appeal to Belief is a fallacy that has this general pattern:
1. Most people believe that a claim, X, is true.
2. Therefore X is true.
This line of "reasoning" is fallacious because the fact that many people believe a claim does not, in general, serve as evidence that the claim is true.

Appeal To Numbers (Argumentum ad numerum)
DEFINITION: This fallacy is closely related to the argumentum ad populum. It consists of asserting that the more people who support or believe a proposition, the more likely it is that that proposition is correct.
EXAMPLE: "Everyone says that Kirk said 'Beam me up, Scotty' all the time on Star Trek. Therefore it's a fact."
PROOF: Identify the proposition and point out that just because many people believe a proposition to be true, does not mean the proposition IS true

Ad Hominem - Attacking the Person (argumentum ad hominem)
DEFINITION: The person presenting an argument is attacked instead of the argument itself. This takes many forms. For example, the person's character, nationality or religion may be attacked. Alternatively, it may be pointed out that a person stands to gain from a favourable outcome. Or, finally, a person may be attacked by association, or by the company he keeps.

Translated from Latin to English, "Ad Hominem" means "against the man" or "against the person."
An Ad Hominem is a general category of fallacies in which a claim or argument is rejected on the basis of some irrelevant fact about the author of or the person presenting the claim or argument. Typically, this fallacy involves two steps. First, an attack against the character of person making the claim, her circumstances, or her actions is made (or the character, circumstances, or actions of the person reporting the claim). Second, this attack is taken to be evidence against the claim or argument the person in question is making (or presenting). This type of "argument" has the following form:
1. Person A makes claim X.
2. Person B makes an attack on person A.
3. Therefore A's claim is false.

Ad Hominem (abusive)
Instead of attacking an assertion, the argument attacks the person who made the assertion.
EXAMPLE: "You think Kirk is better because you are just stupid."

Ad Hominem (tu quoque)
DEFINITION: This form of attack on the person notes that a person does not practise what he preaches. This fallacy is committed when it is concluded that a person's claim is false because 1) it is inconsistent with something else a person has said or 2) what a person says is inconsistent with her actions. This type of "argument" has the following form:
1. Person A makes claim X.
2. Person B asserts that A's actions or past claims are inconsistent with the truth of claim X.
3. Therefore X is false.

Poisoning The Well
DEFINITION: Another variant of Ad Hominem Circumstantial. This sort of "reasoning" involves trying to discredit what a person might later claim by presenting unfavorable information (be it true or false) about the person. This "argument" has the following form:
Unfavorable information (be it true or false) about person A is presented.
Therefore any claims person A makes will be false.[FONT=Times New Roman

Appeal to Authority (argumentum ad verecundiam)
DEFINITION: While sometimes it may be appropriate to cite an authority to support a point, often it is not.
An Appeal to Authority is a fallacy with the following form:
1. Person A is (claimed to be) an authority on subject S.
2. Person A makes claim C about subject S.
3. Therefore, C is true.
This fallacy is committed when the person in question is not a legitimate authority on the subject. More formally, if person A is not qualified to make reliable claims in subject S, then the argument will be fallacious.
This sort of reasoning is fallacious when the person in question is not an expert. In such cases the reasoning is flawed because the fact that an unqualified person makes a claim does not provide any justification for the claim. The claim could be true, but the fact that an unqualified person made the claim does not provide any rational reason to accept the claim as true.

Converse Accident / Sweeping Generalization / Dicto Simpliciter
DEFINITION: An exception to a generalization is applied to cases where the generalization should apply

Okay!!! Which one of your definitions back up your title? Logical Fallacies1. :happy dance

Been Thinkin

[Praxeas]

Begging the Question ( petitio principii ) / Circular Reasoning
DEFINITION: The truth of the conclusion is assumed by the premises. Often, the conclusion is simply restated in the premises in a slightly different form. In more difficult cases, the premise is a consequence of the conclusion. Begging the Question is a fallacy in which the premises include the claim that the conclusion is true or (directly or indirectly) assume that the conclusion is true. This sort of "reasoning" typically has the following form.
1. Premises in which the truth of the conclusion is claimed or the truth of the conclusion is assumed (either directly or indirectly).
2. Claim C (the conclusion) is true.
This sort of "reasoning" is fallacious because simply assuming that the conclusion is true (directly or indirectly) in the premises does not constitute evidence for that conclusion. Obviously, simply assuming a claim is true does not serve as evidence for that claim. This is especially clear in particularly blatant cases: "X is true. The evidence for this claim is that X is true."

Straw Man
DEFINITION: The Straw Man fallacy is committed when a person simply ignores a person's actual position and substitutes a distorted, exaggerated or misrepresented version of that position. This sort of "reasoning" has the following pattern:
1. Person A has position X.
2. Person B presents position Y (which is a distorted version of X).
3. Person B attacks position Y.
4. Therefore X is false/incorrect/flawed.

Circular Definition (Circulus in demonstrando)
DEFINITION: The definition includes the term being defined as a part of the definition. (A circular definition is a special case of a Failure to Elucidate.)
EXAMPLE: Star Trek is sexist because it has sexist undertones. (We would need to know what "sexist" is in order to tell whether the show is "sexist".)

Appeal to Tradition / Argumentum ad antiquitatem / Appeal to the Old or Past or Age
DEFINITION: Appeal to Tradition is a fallacy that occurs when it is assumed that something is better or correct simply because it is older, traditional, or "always has been done." The opposite of Argumentum ad Novitatem.
This sort of "reasoning" has the following form:
1. X is old or traditional
2. Therefore X is correct or better

Argumentum ad nauseam
DEFINITION: This is the incorrect belief that an assertion is more likely to be true, or is more likely to be accepted as true, the more often it is heard. So an Argumentum ad Nauseam is one that employs constant repetition in asserting something; saying the same thing over and over again until you're sick of hearing it.

Plurium interrogationum / Many questions
DEFINITION: This fallacy occurs when someone demands a simple (or simplistic) answer to a complex question.
EXAMPLE: "Can Star Trek be a religion? Yes or no?"
PROOF: Point out that the question is too complex to be answered with a simple answer. Sometimes offering a more complex answer will solve the problem.

Red Herring / Smoke Screen / Wild Goose Chase
DEFINITION: This fallacy is committed when someone introduces irrelevant material to the issue being discussed, so that everyone's attention is diverted away from the points made, towards a different conclusion. The basic idea is to "win" an argument by leading attention away from the argument and to another topic.

This sort of "reasoning" has the following form:
1. Topic A is under discussion.
2. Topic B is introduced under the guise of being relevant to topic A (when topic B is actually not relevant to topic A).
3. Topic A is abandoned.

[Praxeas]

Appeal To Ridicule / Appeal to Mockery / The Horse Laugh / Humor
DEFINITION: The Appeal to Ridicule is a fallacy in which ridicule or mockery is substituted for evidence in an "argument." And/or using inappropriate humor or ridicule to avoid the issue, to cast unwarranted aspersions, or to deflect attention away from the discussion.
This line of "reasoning" has the following form:
1. X, which is some form of ridicule is presented (typically directed at the claim).
2. Therefore claim C is false.

Guilt By Association
DEFINITION: Attacking the idea because of those who support it, or make spurious links between publicly favorable things and publicly unfavorable things

Quoting out of context and there are many more

[ThePastorsCoach]

I think you are trying to be denominal!

[Amanah]

and philosophical

[mizpeh]

and logical...

[RandyWayne]

Begging the Question ( petitio principii ) / Circular Reasoning
DEFINITION: The truth of the conclusion is assumed by the premises. Often, the conclusion is simply restated in the premises in a slightly different form. In more difficult cases, the premise is a consequence of the conclusion. Begging the Question is a fallacy in which the premises include the claim that the conclusion is true or (directly or indirectly) assume that the conclusion is true. This sort of "reasoning" typically has the following form.
1. Premises in which the truth of the conclusion is claimed or the truth of the conclusion is assumed (either directly or indirectly).
2. Claim C (the conclusion) is true.
This sort of "reasoning" is fallacious because simply assuming that the conclusion is true (directly or indirectly) in the premises does not constitute evidence for that conclusion. Obviously, simply assuming a claim is true does not serve as evidence for that claim. This is especially clear in particularly blatant cases: "X is true. The evidence for this claim is that X is true."

I completely understand the fallacy inherent with circular reasoning. So, how does this jive when someone says "Scripture interprets scripture"?