Upload
mark-dickson
View
222
Download
0
Embed Size (px)
Citation preview
7/31/2019 Latin List of Logic Fallacies
1/34
Logical Fallacies
Logic is the study of reasoning -- the nature of good (correct)
reasoning and of bad (incorrect) reasoning. Its focus is the method
by which an argument unfolds, not whether any arbitrary
statement is true or accurate. Thus, an argument can be both
deductively valid and perfectly absurd, as in 1. All telephone poles
are elephants. 2. Sally is a telephone pole. 3. Therefore, Sally is an
elephant. The conclusion is valid because it conforms to a correct
syllogistic pattern -- in this case, affirmation of the antecedent --
but is ludicrous at the same time.
As a "branch" of philosophy, logic is often broken down into
many subsets: for instance, modal logic, many-valued logic, modern
logic, symbolic logic, formal and informal logic, deductive and
inductive logic. Those interested in pursuing the subject in depth
should read and carefully examine the long articles in The
Encyclopedia of Philosophy, especially "A Glossary of Logical
Terms." Each article is followed by an extensive bibliography. (See
also Logic.)
A fallacy is an invalid form of argument, an instance of incorrect
reasoning. Below is a list of common fallacies. Hit the "Back"
button to return to the top.
Page 1 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
2/34
List of Fallacies:
affirming the consequent
anthrocentric fallacy
appeal to authority
a priori fallacies
arguing from "is" to "ought"
argumentum ad baculinum
argumentum ad captandum
argumentum ad crumenam
argumentum ad hominem
argumentum ad ignorantiam
argumentum ad lazarum
argumentum ad misericordiam
argumentum ad populum
argumentum ad verecundiam (see "appeal to authority")
argumentum ex silentio
begging the question
circular reasoning
equivocation
fallacy of false alternatives
fallacies of interrogation
flamboyance
gadarene swine fallacy
genetic fallacy
hasty generalization
if-then fallacies
Page 2 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
3/34
ignoratio elenchi
invincible ignorance
naturalistic fallacy
non sequitur
paralogism
performative contradiction
petitio principii (see "begging the question")
poisoning the wells
post hoc ergo propter hoc
red herring
straw man fallacy
tu quoque fallacy
undistributed middle
Further Investigation
Page 3 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
4/34
affirming the consequent -- A fallacy of the form "if A, then B; B,
therefore A". Example: "If Smith testifies against Jones in court,
Jones will be found guilty. Jones was found guilty. Therefore, Smith
must have testified against him." {Jones could have been found
guilty without Smith's testimony.}
Page 4 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
5/34
anthrocentric (human-centered) fallacy -- This one isn't found in
standard texts, but was described by John Stuart Mill in System of
Logic. Consider the example of a preacher who one day takes
someone supposedly possessed of a demon, throws his hand on her
forehead, and shouts, "Get out! Leave this body!" Even supposing
that demons exist, one might find it curious that they understand
English, obey peremptory commands, and are easily influenced by
incantations and rituals. The a.f. here occurs at the presupposition
level: human language, reason, instincts, and desires are assumed to
be the orbit around which everything else in the universe (including
the aforementioned demons) revolve.
Page 5 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
6/34
7/31/2019 Latin List of Logic Fallacies
7/34
differences in nature must correspond to our received (linguistic)
distinctions; that whatever is, is rationally explicable; that there is no
action at a distance; that every phenomenon has a single cause; and
that effects must resemble their causes. These are all errors, but we
can go further and recognize a general apriorist fallacy, which
consists in trying to base knowledge of fundamental synthetic truths
on anything other than empirical evidence."
arguing from "is" to "ought" -- A fallacy first articulated by
David Hume (1711-1776) in which someone argues from a
premise containing only a descriptive term, to a conclusion
Page 7 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
8/34
containing an "ought." Example: "There is nothing morally
wrong with the institution of slavery. It has been with us in some
form for thousands of years." (The fact that slavery has been with
us or is with us is not moral justification of the act. What is may
not be the same thing as what ought to be.)
argumentum ad baculinum -- Fallacy that occurs when threat of
force is made, either implicitly or explicitly. Example: "I'm
willing to discuss this in even more depth, but if you don't come
around soon, there may be dire consequences." (Baculum from
the Latin means "stick".)
Page 8 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
9/34
argumentum ad captandum -- Any specious or unsound argument
that is likely to win popular acceptance. (literally, "for catching the
common herd").
Page 9 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
10/34
argumentum ad crumenam -- The fallacy of supposing that a
conclusion must be valid because the person making the argument is
wealthy. (Crumena from the Latin means "purse".) An instance of
this fallacy is when someone turns to another and says, "Well, if
you're so smart, why aren't you rich?" One can be both smart and
poor, as indeed numerous philosophers throughout history were
(e.g., Lao-Tzu, Socrates, Spinoza).
argumentum ad hominem ("argument against the person") -- A
common fallacy in which someone argues against a position or claim
by assailing the proponent of it. The truth or falsehood of a position
Page 10 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
11/34
doesn't depend on who does (or doesn't) espouse it. e.g. "You can't
trust Jones' theory of electromagnetic particles because he's a
communist." (The theory is good or bad because it comports (or
doesn't comport) with certain facts and evidence, not because the
man propounding it holds a political affiliation.)
argumentum ad ignorantiam ("arguing from ignorance") -- A
fallacy that occurs when someone argues that because we don't
know something is true, it must be false, or because we lack
proof that a statement is false, it must be true. Ignorance or lack
of evidence doesn't necessarily mean a position or claim is true
or false. Common Examples: "No one has ever proven that
UFOs exist. Therefore, they don't exist." (Something can exist
despite the absence of confirmation. Lack of proof is
justification for caution or even scepticism, but not dogmatic
assertions.) "There is simply no proof that God exists. Therefore,
God doesn't exist." (God might exist even though there is no way
empirically to prove it.)
Page 11 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
12/34
argumentum ad lazarum -- The fallacy of supposing a conclusion
is valid because the argument is made by a poor person. It is the
opposite of the ad crumenam fallacy.
Page 12 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
13/34
argumentum ad misericordiam -- Occurs when an appeal is made to
pity or to one's sympathetic nature. Example: "Augusto Pinochet is
an old, dying man. It is wrong to make him stand trial for alleged
offenses."
Page 13 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
14/34
argumentum ad populum -- This fallacy occurs when an argument
panders to popular passion or sentiment. When, for instance, a
politician exclaims in a debate that his opponent "is out of step with
the beliefs of everyone in the audience," he/she is committing the
fallacy. The legitimacy of a statement depends not on its popularity,
but on its truth credentials.
Page 14 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
15/34
argumentum ex silentio -- The fallacy of supposing that someone's
silence is necessarily proof of ignorance. Two people, for instance,
may be debating a political issue on a cable news program. One may
be in the studio with the host, the other appearing via satellite. Their
time on air reaches the point when each only has a few seconds left
to make a closing comment. One of the debaters asks his opponent a
very technical, complex question, and the opponent is speechless for
a few seconds. "Go ahead," the debater screams. "Answer my
question! See? He can't answer." A viewer may be left with the
impression that the person's speechlessness is tantamount to
ignorance, when in fact any number of things could have happened:
1) the satellite connection could've been lost or experiencing
problems; 2) the debater was thinking about how best to answer a
difficult question under such an immediate time constraint; 3) the
debater might not have even heard the whole question. There may be
reasons for temporary silence other than ignorance.
Page 15 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
16/34
begging the question -- Circular reasoning in which a claim is
assumed to be true and is then tucked in the conclusion. e.g.
"Government by the people is ideal because democracy is the leastinadequate form of government." ("Government by the people" is
the working definition of democracy; the first part of the statement
needs to be proven, not reasserted in the predicate.)
Page 16 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
17/34
circular reasoning -- Sometimes known as circulus in demonstrando,
or begging the question. H.W. Fowler, inModern English Usage,
puts it this way: "The basing of two conclusions each upon the other.
That the world is good follows from the known goodness of God;
that God is good is known from the excellence of the world he has
made."
equivocation -- Sometimes referred to as "amphiboly". A fallacy that
stems from the ambiguous meaning of certain words. For example,1. Only man is logical. 2. No woman is a man. 3. Therefore, no
woman is logical. "Man" in the first sentence really means
"mankind," "humankind," "homo sapiens". "Man" in the second
sentence means "maleness". The syllogism appears to be valid, but
in fact is fallacious because of the subtle shift in meaning.
Page 17 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
18/34
fallacy of false alternatives -- A fallacy occurring when the number
of alternatives is said to be fewer than the actual number. Common
examples of this fallacy are statements containing either/or,
nothing/but, all-or-nothing elements. Examples: "Is she a Democrat
or a Republican?" (She may be a socialist, a libertarian, a Leninist,
an anarchist, a feminist or any number of other things, including one
who is strictly apolitical.) "If you aren't for your country, then you
are against it." (One may be neither "for" nor "against" but may
occupy a position of strict neutrality or be affirmative sometimes and
critical at others.)
Page 18 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
19/34
fallacies of interrogation -- There are two forms of this particular
fallacy. One is asking two or more questions and demanding a single
answer when, in fact, each question might require separate
treatment. The other form is asking a question whose answer would
necessitate acceptance of a presupposition, one which the answerer
might separately deny. The famous example of this second form is
asking, "Do you still beat your wife?" Answering "no" legitimates
the question and does nothing to contradict the presupposition that
the husband once did beat his wife. Asking a question with
presuppositions is fine so long as a narrow answer is not demanded.
Page 19 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
20/34
flamboyance -- The manner in which someone speaks can easily
draw unwarranted support for a thesis or idea. Incisive wit, verbal
facility, equanimity and repartee have no bearing at all on the
soundness/legitimacy of a position. It is the essence of what is said,
not the manner in which it is said, that counts. As Bertrand Russell
once noted, the purpose of being educated is to defend ourselves
against the seductions of eloquence.
genetic fallacy -- A fallacy that occurs when someone attacks the
cause or origin of a belief rather than its substance. Why a person
believes something is not relevant to the belief's
legitimacy/soundness/validity. Example: "Smith's belief in God
stems from a subsconscious need for a fatherly figure and is thus a
Page 20 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
21/34
total joke." (The psychological link may in fact be true and may
even shed some light on the personality of Smith, but is nevertheless
irrelevant to the truth/falsehood of his belief.)
hasty generalization -- The habit of arriving at a bold conclusion
based on a limited sample of evidence. This often occurs with
statistics. For instance, someone may ask ten women and one man
what their opinion is of contemporary male-female relationships and
from this sample draw a sweeping conclusion; hasty generalization
would then be said to exist.
Page 21 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
22/34
if-then fallacies -- 1. Affirming the consequent(If P, then Q. Q.
Therefore P.). 2. Denying the antecedent(If P, then Q. Not P.
Therefore not Q.) 3. Converting a conditional(If P, then Q.
Therefore if Q, then P.) 4. Negating antecedent and consequent(If
P, then Q. Therefore if not P, then not Q.)
Page 22 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
23/34
7/31/2019 Latin List of Logic Fallacies
24/34
invincible ignorance -- the fallacy of insisting on the legitimacy of
one's position in the face of contradictory facts. Statements like "I
really don't care what the experts say; no one is going to convince
me that I'm wrong"; "nothing you say is going to change my mind";
"yeah, okay, whatever!" are examples of this fallacy.
naturalistic fallacy -- From theEncyclopedia of Philosophy: "What
G.E. Moore called the naturalistic fallacy is the identifying of
goodness with any natural characteristic, such as pleasantness or
being the object of desire. If there is a distinct property, goodness, it
will of course be an error to identify it with any other feature, even if
the two are coextensive, and this would be an example of the refusal
to distinguish what we cannot separate; however, it must first be
Page 24 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
25/34
shown that there is such a property as Moore's goodness.
Alternatively, if it is a question of how the word 'good' is commonly
used, then it would be an error to say that it is used to convey somenatural description. However, if the naturalist is not trying to report
the ordinary use, but is saying that this ordinary use is somehow
unsatisfactory (and also that there is no such property as the one of
which Moore speaks) and is therefore proposing a different use,
where is his mistake? It is true that if he redefines 'good' as the name
of some natural characteristic, but still also uses the word in its
ordinary evaluative or prescriptive sense, he will be slipping into a
fallacy of ambiguity; but a consistent ethical naturalist may be
committing no fallacy at all."
non sequitur ("it does not follow") -- A statement that does not
logically follow from what preceded it; a conclusion that does not
follow from the premises.
Page 25 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
26/34
paralogism -- Any fallacious or illogical argument generally.
Page 26 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
27/34
poisoning the wells -- This entry comes from an article by Albury
Castell titled "Analyzing A Fallacy," which was included in the
book Readings In Speech, edited by Haig Bosmajian (Harper &
Row, 1965). Here is the full quote: "During the last century a
famous controversy took place between Charles Kingsley and
Cardinal Newman. It began, I believe, by Kingsley suggesting that
truth did not possess the highest value for a Roman Catholic priest;
that some things were prized above truth. Newman protested that
such a remark made it impossible for an opponent to state his case.
How could Newman prove to Kingsley that he did have more regard
for truth than for anything else, if Kingsley argued from the premiss
that he did not? It is not merely a question of two persons
entertaining contradictory opinions. It is subtler than that. To put it
baldly, Newman would be logically 'hamstrung.' Any argument he
might use to prove that he did entertain a high regard for truth was
automatically ruled out by Kingsley's hypothesis that he did not.
Page 27 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
28/34
Newman coined the expressionpoisoning the wells for such unfair
tactics...The phrasepoisoning the wells exactly hits off the difficulty.
If the well is poisoned, no water drawn from it can be used. If a case
is so stated that contrary evidence is automatically precluded, no
arguments against it can be used."
post hoc, ergo propter hoc ("after this, therefore because of this") --
This might also be described as the causality fallacy: Event Y
follows from EventX, so one automatically concludes thatXcaused
Y. (A young man walks by a neighbor's house and sees a cat
scurrying away; he looks up and sees a giant hole in the window.
Page 28 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
29/34
The hole, he infers, must have been caused by the cat, who fell
through the pane. The inference is hasty, because the hole might
have been caused by any number of things -- a baseball that missed a
friend's glove and flew over his head; young brothers fighting inside
and accidentally smashing the window, etc.).
red herring -- An attempt to divert attention from the crux of an
argument by introduction of anecdote, irrelevant detail, subsidiary
facts, tangential references, and the like.
Page 29 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
30/34
straw man -- A fallacy that occurs when someone attacks a lessdefensible position than the one actually being put forth. This occurs
very often in politics, when one seeks to derive maximum approval
for himself/herself or for a cause. Example: "Opposition to the North
American Free Trade Agreement amounts to nothing but opposition
to free trade." (Someone can believe in free and open trade and yet
still oppose NAFTA.)
Page 30 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
31/34
tu quoque ("you too") fallacy -- The fallacy of assuming an
argument is specious because it is either inconsistent with the
person's actions or inconsistent with previous claims/arguments. A
person may "preach" about something and act in a very different
manner, but this fact has no bearing on the specific argument he is
advancing at any time. Inconsistency, moreover, may raise issues of
hypocrisy or double standards, but it does not bear upon the
argument at hand. Example: "Smith: If someone hits you, you shouldturn the other cheek. Violence only begets violence, and violence in
and of itself is wrong.Jones: That's a joke. You used to hit people
when they picked a fight with you." (Smith may not have practiced
what he now preaches, but two of his premises -- that violence only
begets violence, and that violence is wrong -- need to be carefully
examined.)
Page 31 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
32/34
undistributed middle -- A fallacy of the form "All A are B. All C are
B. Therefore, all A are C." Consider: All elms are trees. All oaks are
trees. Therefore, all elms are oaks.
Page 32 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
33/34
Further Investigation
Years of intense study and training are not needed to develop a
rough understanding of logic or, for that matter, of any other branch
of philosophy. Much ground can be gained by reading a few
chapters of several books, by foraging through various collections in
used or old bookstores, and by visiting a few good sites on the web.
Below is a list of prominent logicians and their work:
Aristotle: Categories; On Interpretation;Prior Analytics;
Posterior Analytics; Topics; Sophistical Refutations.
Francis Bacon:Novum Organum
Descartes:Discourse on Method
John Dewey: Reconstruction In Philosophy
John Stuart Mill: System of Logic
W.V. Quine,Mathematical Logic.
Bertrand Russell: The Problems of Philosophy; The Principles of
Mathematics.
Gilbert Ryle: Dilemmas
Ludwig Wittgenstein: Philosophical Investigations
Other Works:
Rudolf Carnap, Introduction to Symbolic Logic and its
Applications.
Alonzo Church,Introduction to Mathematical Logic.
M.R. Cohen & Ernest Nagel,An Introduction to Logic and
Page 33 of 34Logical Fallacies
2010/04/20http://www.philosophicalsociety.com/Logical%20Fallacies.htm
7/31/2019 Latin List of Logic Fallacies
34/34
Scientific Method.
W.W. Fearnside & W.B. Holther,Fallacy -- The Counterfeit of
Argument.
- Return Home -
Page 34 of 34Logical Fallacies