Tautology Wiki


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)



Robert D. Coleman, PhD © 2006 rcoleman@mba1971.hbs.edu


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


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


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


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/


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


http://en.wikipedia.org/wiki/Circular_reasoning Wikipedia: Circular reasoning In logic , begging the question

is the term for a type of 


occurring in 

deductive reasoning

in which the 


to be 


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


circular reasoning . As a concept in logic

the first known definition in the West is by the 

Greek philosopher Aristotle


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.