Circular reasoning

=== tiktaalik ===
Section to be merged with Logical fallacies. 
If the Tiktaalik fossil had no kids, how could he be the ancestor of anybody?
* We don't know where the organism died , it could have died 500miles away and was fossilized in a huge flood somewhere else. 
* We have no written records older than 5000 years.(check this pending)
=== circularity ===
http://www.numeraire.com/download/WhatIsCircularReasoning.pdf 
Robert D. Coleman, PhD © 2006 rcoleman@mba1971.hbs.edu 
 1 
What Is Circular Reasoning? 
Logical fallacies are a type of error in r
easoning, errors which 
may be recognized and 
corrected by observant thinkers. There are a 
large number of informal
 fallacies that are 
cataloged, and some have multiple names. The frequency of occurrence is one way to 
rank the fallacies. The ten most-frequent 
fallacies probably cover the overwhelming 
majority of illogical reasoning. With a Pareto
 effect, 20% of the major fallacies might 
account for 80% of fa
llacious reasoning. 
One of the more common fallacies is circul
ar reasoning, a form of which was called 
“begging the question” by Aristotl
e in his book that named the fa
llacies of classical logic. 
The fallacy of circular reasoning occurs 
when the conclusion of an argument is 
essentially the same as one of the premises 
in the argument. Circular reasoning is an 
inference drawn from a premise that incl
udes the conclusion, and used to prove the 
conclusion. Definitions of words are circul
ar reasoning, but they are not inference. 
Inference is the deriving of a conclusion in
 logic by either induction or deduction. 
Circular reasoning can be quite 
subtle, can be obfuscated when intentional, and thus can 
be difficult to detect. 
Circular reasoning as a fallacy refers to reas
oning in vicious circle
s or vicious circular 
reasoning, in contrast to reas
oning in virtuous circles or 
virtuous circular reasoning. 
Virtuous circular reasoning is sometimes used
 for pedagogical purposes, such as in math 
to show that two different statements are eq
uivalent expressions of the same thing. In a 
logical argument, viciously circular reasoni
ng occurs when one attempts to infer a 
conclusion that is based upon a premise that 
ultimately contains 
the conclusion itself. 
Why is vicious circular reasoning unacceptabl
e and fatal? Genuine method proceeds from 
the known to the unknown. Vicious circular 
reasoning proceeds from the known to the 
equally known. Vicious circul
ar reasoning, therefore, viol
ates genuine method. Vicious 
circular reasoning does not a
dd anything new, it does not advance learning, and it does 
not add to knowledge. Vicious circular re
asoning goes nowhere and leads nowhere -- 
hence, its descriptive name “circular”. It
 literally moves in a circuit or a circle. 
Most people do not study logica
l fallacies as part of their formal education. Those who 
study them typically do so as part of a course
 in logic, maybe calle
d critical thinking, in 
the philosophy department. The rest of us have
 to learn about them on our own in order to 
make and detect sound arguments. Note that
 the word argument applies to all reasoning 
regardless of form, and thus it includes 
hypotheses, models, arguments and studies. 
Here are the citations for a classical te
xt and for a modern text about logic. 
Prior Analytics and Topics
, Aristotle 
The Logic of Real Arguments
, Alec Fisher, Second Edition, 2004, Cambridge 
University Press. 
Robert D. Coleman, PhD © 2006 rcoleman@mba1971.hbs.edu 
 2 
The following is a list of Internet sites with
 information about the fallacies of informal 
logic including the fallacy of circular reas
oning, begging the question, or petitio principii. 
http://www.kcmetro.cc.mo.us
/longview/CTAC/fallacy.htm
Critical Thinking Across the Curric
ulum Project: Informal Fallacies 
Table of Contents (17 Fallacies) 
Fallacies of Deception: 
Fallacies of Distraction:
Fallacies involving Counterfeit:
False Dilemma
Affirming the Consequent
Slippery Slope
Denying the Antecedent
Straw Man
Equivocation
Begging the Question
or Circularity
Fallacies which use Emotion or Motive in place of Support
: 
Appeal to Pity
Appeal to Authority
Appeals to Tradition 
Prejudicial Language
Appeal to Force
 Appeal to Mass Opinion 
Fallacies which employ both (Double Trouble):
Ad Hominem - Abusive
 Ad Hominem - Ridicule 
Ad Hominem - Circumstantial
Tu Quoque - Two wrongs
http://www.ramdac.org/fallacies.php
Fallacy Tutorial Pro 3.0, 1995, Dr. Mich
ael C. Labossiere (42 fallacies) 
Introduction. Description of Fallacies. 
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 argu
ment such that the premises provide (or 
appear to provide) some degree of support (b
ut 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 pr
emises are true, then its conclusion must be 
true. If all the argument is va
lid 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 
Robert D. Coleman, PhD © 2006 rcoleman@mba1971.hbs.edu 
 3 
good inductive argument is known as a strong (o
r "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 reasoni
ng. This differs from a factual error, which 
is simply being wrong about the facts. To be mo
re 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 ar
gument 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 suppor
t for the conclusion. In such cases, even 
if the premises were true, the conclusion 
would not be more likely to be true. 
http://www.iep.utm.edu/f/fallacies.htm
The Internet Encyclopedia of Philosophy (164 fallacies) 
A fallacy is a kind of error in reasoning. Th
e alphabetical list be
low contains 164 names 
of the most common fallacies, and it provide
s explanations and examples of each of 
them. Fallacies should not be persuasive, but 
they often are. Fallacies may be created 
unintentionally, or they may be 
created intentionally in order to deceive other people. The 
vast majority of the commonly identified 
fallacies involve argu
ments, although some 
involve explanations, or definitions, or othe
r products of reasoning. Sometimes the term 
"fallacy" is used even more broadly to indicate
 any false belief or cause of a false belief. 
The list below includes some fallacies of this
 sort, but most are fallacies that involve 
kinds of errors made while argui
ng informally in natural language. 
The discussion that precedes th
e list begins with an account of
 the ways in which the term 
"fallacy" is vague. Attention then turns to
 the number of competing and overlapping 
ways to classify fallacies of argumentation. 
 For pedagogical purposes, researchers in the 
field of fallacies disagree about the followi
ng topics: which name of a fallacy is more 
helpful to students' understanding; whether so
me fallacies should be de-emphasized in 
favor of others; and which is the best taxonomy 
of the fallacies. Researchers in the field 
are also deeply divided about 
how to define the term "falla
cy," how to define certain 
fallacies, and whether any general theory of 
fallacies at all should 
be pursued if that 
theory's goal is to provide necessary and sufficient conditions for distinguishing between 
fallacious and non-fallacious reas
oning generally. Anal
ogously, there is doubt in the field 
of ethics regarding whether researchers s
hould pursue the goal of providing necessary 
and sufficient conditions for distinguishing moral actions from immoral ones. 
Introduction 
The first known systematic study of fa
llacies was due to Aristotle in his 
De Sophisticis 
Elenchis
 (Sophistical Refutations
), an appendix to the 
Topics
. He listed thirteen types. 
After the Dark Ages, fallacies were again st
udied systematically in Medieval Europe. 
This is why so many fallacies have Latin na
mes. The third major period of study of the 
fallacies began in the later twentieth century 
due to renewed interest
 from the disciplines 
Robert D. Coleman, PhD © 2006 rcoleman@mba1971.hbs.edu 
 4 
of philosophy, logic, communication studies
, rhetoric, psychology, and artificial 
intelligence. 
The term "fallacy" is not a pr
ecise term. One reason is that 
it is ambiguous. It can refer 
either to (a) a kind of error in an argume
nt, (b) a kind of error in reasoning (including 
arguments, definitions, explanations, etc.), (c) a 
false belief, or (d) the cause of any of the 
previous errors including what are norma
lly referred to as "rhetorical techniques". 
Philosophers who are researcher
s in fallacy theory prefer 
to emphasize meaning (a), but 
their lead is often not followed in
 textbooks and public discussion. 
http://www.hebrew4christians.com/Clear_Thinking/
Informal_Fallacies/Informal_Fallacies.html
Informal Fallacies (71 fallacies in 11 categories) 
You simply cannot properly begin to properly 
read the various texts without first being 
grounded in the basics of clear thinking. By 
familiarizing yourself with these forms of 
reasoning you may guard yourself from making th
e same sorts of errors (as well as to 
catch errors in the thinking 
of others who purport to be 
speaking the truth). A brief 
introduction of the subject included. 
An informal fallacy is an attempt to persuade
 that obviously fails to
 demonstrate the truth 
of its conclusion, deriving its 
only plausibility from a misuse
 of ordinary language. Most 
scholars categorize informal fallacies as: (1)
 fallacies of relevance
: appeal to ignorance, 
appeal to authority, ad hominem arguments, 
appeals to emotion, force, etc., irrelevant 
conclusions, and appeals to pity; (2) 
fallacies of presumption
: accident, converse 
accident, false cause, begging the qu
estion, and complex question; (3) 
fallacies of 
ambiguity
: equivocation, amphiboly, accent,
 composition, and division. 
http://www.datanati
on.com/fallacies/
Stephen’s Guide to the Logi
cal Fallacies (53 fallacies) 
http://www.adamsmith.org/logicalfallacies/
Adam Smith Institute Logical Fallacies (76 fall
acies, incuding Petito Principii, Circulus 
in Probando, and Blinding with Science) 
http://www.drury.edu/ess/Logic/Informal/Overview.html
A Database of Informal Fallacies
, 1987, Dr. Charles Ess (28 fallacies) 
http://www.csun.edu/~dgw61315/fallacies.html
Logical Fallacies and the Art 
of Debate (21 fallacies, in
cluding Petitio Principii and 
Circulus in Demonstrando) 
http://www.fallacyfiles.org/
 and 
http://www.fallacyfile
s.org/begquest.html
The Fallacy Files (155 fallacies, including 
Circular Argument, 
Circulus in Probando, 
Petitio Principii, Question-
Begging, and Vicious Circle) 
http://en.wikipedia.org/wiki/Logical_fallacy
Wikipedia: Logical fallacy (111 falla
cies, including Begging the Question) 
Robert D. Coleman, PhD © 2006 rcoleman@mba1971.hbs.edu 
 5 
http://en.wikipedia.org/wiki/Circular_reasoning
Wikipedia: Circular reasoning 
In 
logic
, 
begging the question
 is the term for a type of 
fallacy
 occurring in 
deductive 
reasoning
 in which the 
proposition
 to be 
proved
 is assumed implicitly 
or explicitly in one 
of the 
premises
. For an example of this, cons
ider the following argument: "
Only an 
untrustworthy person would run for office. The 
fact that politicians are untrustworthy is 
proof of this.
" Such an argument is fallacious, because it relies upon its own 
proposition—in this case, "politicians are 
untrustworthy"—in order 
to support its central 
premise. Essentially, the argument assumes th
at its central point is already proven, and 
uses this in support of itself. 
Begging the question is also known by its Latin name 
petitio principii
 and is related to 
the fallacy known as 
circular argument
, 
circulus in probando
, 
vicious circle
 or 
circular 
reasoning
. As a concept in 
logic
 the first known definition in the West is by the 
Greek
philosopher
Aristotle
 around 
350 B.C.
, in his book 
Prior Analytics
, where he classified it 
as a 
material fallacy
. 
The term is usually not used to
 describe the broader fallacy th
at occurs when the evidence 
given for a proposition is as much in need 
of proof as the proposition itself. The more 
accepted classification for such arguments is as a 
fallacy of many questions
. 
See 
modern usage controversy
, below, over a common usage of "begs the question" with 
the meaning "raises the question". 
http://en.wikipedia.org/wiki/Category:Causal_fallacies
Wikipedia: Causal fallacies 
This category is for 
questionable cause
 fallacies, arguments where a cause is incorrectly 
identified. 
http://en.wikipedia.org/wiki/Category:Informal_fallacies
Wikipedia: Informal fallacies 
This category is for arguments that are fa
llacious for reasons ot
her than structural 
("formal") flaws, such as due to ambigu
ity or a common error in their premises. 
Category:TauTology
Category:Circularity
Category:Logical fallacies