Fallacy

The Penguin® English Dictionary - Penguin.
1. a false idea:
the popular fallacy that scientists are illiterate.
2. in logic, an argument
failing to satisfy the conditions of valid inference.[Latin fallacia, from
fallac-, fallax deceitful, from fallere to deceive].

Fallacy

The New Dictionary of Cultural Literacy, Houghton Mifflin
Company®.
A false or mistaken idea based on faulty knowledge or reasoning.
For example, kings who have divorced their wives for failing to produce a son
have held to the fallacy that a mother determines the sex of a child, when
actually the father does. (See sex chromosomes).

Fallacy

Chambers 21st Century Dictionary - Chambers Harrap Publishers

noun (fallacies) 1. a mistaken notion.
2. a mistake in reasoning that
spoils a whole argument. See also logic, syllogism. [from Latin fallax
deceptive.]

Fallacy

Roget's II: The New Thesaurus - Houghton Mifflin Company®

noun 1. An erroneous or false idea: erroneousness, error, falsehood,
falseness, falsity, untruth.
2. Plausible but invalid reasoning: casuistry,
sophism, sophistry, speciousness, spuriousness.See correct, true.

Fallacy

A Dictionary of Philosophy, Macmillan® - Macmillan Publishers

An argument involving an invalid, rather than a valid, form of reasoning. For
example, it would be fallacious to argue: given that 'All Communists claim to
repudiate racial discrimination', and given that 'Dr. Smith claims to repudiate
racial discrimination', then it must follow that 'Dr. Smith is a Communist'.
For, although the conclusion may be true, it cannot validly be deduced from
those premises. The argument is thus one token of the type traditionally
labelled the fallacy of the undistributed middle. The word 'fallacy' is often
used loosely in general language to characterize any supposed error, and a clear
distinction must be made between this general usage and the strictly logical
usage in which its function is to distinguish one particular kind of
error.

Fallacy

Crystal Reference® Encyclopedia - Crystal Reference

In logic, an invalid inference. ‘All cats are mammals, Fido is a mammal;
therefore Fido is a cat’ is a fallacy, easily confused with the valid ‘All cats
are mammals, Fido is a cat; therefore Fido is a mammal’. An argument can of
course be valid but have a false conclusion, or be invalid and have a true one.
In everyday speech the word fallacy is used much more generally to denote a
mistake or error. See deduction, induction (logic), inference.

Fallacy

Collins English Dictionary - HarperCollins

noun plural -cies 1. an incorrect or misleading notion or opinion based on
inaccurate facts or invalid reasoning.
2. unsound or invalid
reasoning.
3. the tendency to mislead.
4. Logic an error in reasoning that
renders an argument logically invalid. [from Latin fallcia, from fallax
deceitful, from fallere to deceive].

Fallacy

The Penguin Dictionary of Psychology - Penguin

An argument involving logically invalid or improper reasoning and, by
extension, a conclusion reached by such fallacious reasoning. Note that the
meaning of the term depends on the reasoning and not on what is reasoned.
Although fallacies usually lead to false conclusions they do not do so by
definition; it is quite possible to reach a valid conclusion by faulty
means.

Fallacy

The American Heritage® Dictionary of the English Language -
Houghton Mifflin Company

n. pl. fallacies.
1. A false notion.
2. A statement or an argument
based on a false or invalid inference.
3. Incorrectness of reasoning or
belief; erroneousness.
4. The quality of being deceptive.
[Alteration of
Middle English fallace, from Old French, from Latin fallcia, deceit, from fallx,
fallc-, deceitful, from fallere, to deceive.]

Fallacy

The Companion to British History, Routledge

Aristotle classified fallacies as
1. material, or misstatements of
facts:
2. verbal or misuse of words:
3. formal or contrary to logic:
or
4. accidental or proceeding from the general to the particular. This
system made its way into Christian thought.

J.S. Mill classified them into fallacies
1. of simple inspection including
prejudices;
2. of observation;
3. of generalisation;
4. of
ratiocination or induction;
5. Of confusion including ambiguity.

Close inspection suggests that the two philosophers were farther apart in
time than substance.

Fallacy

The Columbia Encyclopedia - Columbia University Press

In logic, a term used to characterize an invalid argument. Strictly speaking,
it refers only to the transition from a set of premises to a conclusion, and is
distinguished from falsity, a value attributed to a single statement. The laws
of syllogisms were systematically elaborated by Aristotle, and for an argument
to be valid, it must adhere to all the laws; to be fallacious, it need only
break one (see syllogism). The term fallacy has come to be used in a somewhat
wider sense than the purely formal one. Informal fallacies are said to occur
when statements are ambiguous or vague as to the logical form they represent, or
when a multiplicity of meaning is present and the validity of the argument
depends on switching meanings of a word or a phrase in midstream.

Fallacy

Encyclopædia Britannica Article

In logic, erroneous reasoning that has the appearance of soundness. Among
numerous types of logical fallacies that have been noted, some of the better
known are: post hoc ergo propter hoc (“after this, therefore,
because of this”), in which something is assumed to be the cause of something
else merely because it was antecedent in time; ad hominem (“against the man”),
attacking an individual rather than establishing pertinent facts; and circulus
in probando (“arguing in a circle”; also called petitio principii, “begging the
question”), attempting to demonstrate a conclusion by means of premises that
presuppose that conclusion.

Informal fallacy

The Cambridge Dictionary of Philosophy - Cambridge
University Press

An error of reasoning or tactic of argument that can be used to persuade
someone with whom you are reasoning that your argument is correct when really it
is not. The standard treatment of the informal fallacies in logic textbooks
draws heavily on Aristotle’s list, but there are many variants, and new
fallacies have often been added, some of which have gained strong footholds in
the textbooks. The word ‘informal’ indicates that these fallacies are not simply
localized faults or failures in the given propositions (premises and conclusion)
of an argument to conform to a standard of semantic correctness (like that of
deductive logic), but are misuses of the argument in relation to a context of
reasoning or type of dialogue that an arguer is supposed to be engaged in.
Informal logic is the subfield of logical inquiry that deals with these
fallacies. Typically, informal fallacies have a pragmatic (practical) aspect
relating to how an argument is being used, and also a dialectical aspect,
pertaining to a context of dialogue-normally an exchange between two
participants in a discussion. Both aspects are major concerns of informal
logic.

Fallacy

Engelsk - Norsk ordbok, Clue® International Corporation

villfarelse, feilaktig antakelse
feilslutning, feil
bedragersk
natur
bedragersk natur, falskhet

Fal•la•cious

WEBSTER'S II New Riverside University Dictionary

(fæ-lã'shæs) adj. 1. Containing fundamental errors
in reasoning 2. Misleadning: deceptive.
-fal•la´cious•ly
*syns: FALLACIOUS, FALSE,
ILLOGICAL, INVALID, SOPHISTIC, SPECIOUS, SPURIOUS adj. core meaning :
containing fundamental errors in reasoning <a fallacious
argument> <fallacious logic>

Fal•la•cy

WEBSTER'S II New Riverside University Dictionary

(fæl'ã-se) n., pl.-cies. [Lat. fallacia,
deceit < falax, deceitful < fallere, to deceive.]
1. A false notion. 2. A statement or argument
based on a false or invalid inference. 3. Incorrectness of
reasoning or belief. 4. The quality of being deceptive.

Fallacy

1911-utgaven av Encyclopedia Britanica

((Lat. fall-ax, apt to mislead) the term given generally to any
mistaken statement used in argument; in Logic, technically, an argument which
violates the laws of correct demonstration.