Fallacies
A fallacy is a defect or
flaw in an
ARGUMENT that arises from a source other than a false premise.
It is an error of reasoning, not an error of fact.
An argument
is a specific combination of statements in which one or more statement
is claimed to give evidence or reason for another
a.
Premises -
those statements that are said to support the conclusion
b. Conclusion - the
statement that is said to be supported by or to follow from by the premises
Fallacies of
Relevance: These arise when one advances a premise that is not
relevant to the conclusion in question.
Subjectivist Fallacy:
The claim that truth in objective matters of fact is relative to the
individual. This may (perhaps) be
seen as a fallacy of relevance insofar as it is employing an irrelevant
standard – the subjective (v. objective) standard.
Red
Herring: This
occurs when someone introduces
material that is irrelevant to the issue being
discussed, so that attention is diverted away from the points made,
towards a different conclusion. Strictly, this
is more of a ploy than a fallacy.
Appeals
There are many types of appeals: appeals to authority, popular
opinion, ignorance, etc. These appeals - which are made to add support to
a conclusion - may all be legitimate in certain circumstances.
They are fallacious, however, when such appeals are irrelevant to the
conclusion.
Appeal
to Authority - such an appeal is fallacious when the appeal is made to someone
or something that is not a qualified authority in the matter at issue.
Appeal
to Ignorance -
the
arguer uses the fact that nothing has been proved about something as
evidence in support of a conclusion about that thing.
This is fallacious when the absence of evidence
has no bearing on the asserted conclusion.
One prevalent type of
appeal is the APPEAL TO EMOTION.
These appeals come in many forms – appeals to desire
or aversion (“wishful thinking”), fear
(“scare tactics”), pity, vanity or pride (“apple-polishing”), anger or indignation. These
appeals are fallacious when the emotion is not relevant to issue or claim at
hand. The common pattern of these
fallacies is to appeal to the emotion as an inducement to accept or reject the
claim. As a general matter,
however, the consequences (emotional or otherwise) of accepting or rejecting a
claim have no bearing on the truth of the claim.
Genetic Fallacy:
Rejection of a claim solely on the grounds of its source, its origins, or its
associations.
Ad Hominem
(to the man): The attempt to refute a claim by criticizing the person that is
source of the claim. This is a
particular instance of the genetic fallacy.
Straw Man: An
opponent’s actual position is ignored and instead presented in a distorted
or exaggerated fashion. Then the
distortion is easily refuted and victory is claimed.
Fallacies
of Vacuity
These occur when the argument is empty in that it is lacking a necessary
element to advance the argument.
Circular Reasoning:
The argument assumes what it purports to
prove. Note that upon this
definition all valid (deductive) arguments
are instances of circular reasoning. Such
arguments are not completely vacuous, i.e., viciously circular, when they make
explicit that which was only implicit.
Begging the Question
(Petitio Principii): An argument in which any objection to the
conclusion is also an objection to one of its premises, and that premise is
not supported by any independent evidence.
An argument begs the question if and only if one would not
have reason to believe a premise is true unless one already had reason to
believe the conclusion were true. Thus one begs (petitio) the
other person to accept the conclusion at the onset of the argument.
Non Sequitur:
An argument in which the conclusion does not follow from the premises.
Fallacies
of Clarity:
These occur when the concepts used in arguments are themselves
unclear (vague or ambiguous) and the lack of clarity results in
an error or defect in the argument.
Line-Drawing Fallacy:
A concept is dismissed as unclear, meaningless, or inapplicable because of the
inability draw a line to demarcate the edge of the concept.
Equivocation:
The wavering between two different meanings of an ambiguous term in an
argument.
Fallacy of Composition:
Mistakenly thinking that what holds true of individuals in
a group
holds true of the group itself.
Fallacy of Division:
Mistakenly thinking that what holds true of a group
necessarily holds true
of each of the individuals in the group.
Miscellaneous Fallacies
False Dilemma: An
erroneous or artificial narrowing of alternatives - argues that there are only
two alternatives in a given situation (either/or; all/nothing) when, in fact,
there are more than two.
Slippery Slope:
The conclusion of an argument rests upon an alleged or assumed chain reaction
and there has been insufficient evidence advanced to support the fact that
such a chain reaction would occur.