Logical Fallacies 1

[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