Complete definition and the classification of fallacy …

Spread the love
Definition and the classification of fallacy....

Definition and the classification of fallacy….

Definition and the classification of fallacy… …A fallacy is a type of argument that may seem to be correct but that proves, on examination, not to be so.  From the foregoing, it is clear that “a fallacy has two features: first, it is an argument; second, its premises provide no support to the conclusion though they appear to do so, because the argument is psychologically persuasive”. There are ‘Formal’ and ‘Informal’ fallacies.

  • Formal fallacies are the types of mistakes we make in our attempt to construct syllogisms (deductive reasoning/a logical argument with two premises and a conclusion) or in using logical
  • Informal fallacies, on the other hand, are the types of errors in reasoning that occur as a result of carelessness or inattention to the content of the propositions constituting an

In this article, we shall focus on Informal Fallacy which can be classified into three broad categories, namely,

  1. fallacies of relevance,
  2. fallacies of ambiguity, and
  3. fallacies of presumption.

Fallacies of Relevance

These are fallacies whose premises appear to be relevant to the conclusion drawn but, on close examination, are simply not relevant. The following below are fallacy under this category:


The Appeal to Force (argumentum ad baculum)

This fallacy is committed when one resorts to the use of threat to cause the acceptance of a conclusion, especially when evidence or rational methods fail.In other words, this fallacy is committed when an argument relies on the threat of force, though the threat may be veiled and not necessarily be physical. For instance, I’ll be committing this fallacy if I threatento fail students who disagree with my political ideologies. This means that the fallacy can be committed by someone in a position of power if he uses threat to coerce his opponents to accept his proffered proposition. The following are examples of arguments that commit this fallacy:

  • All fresh students in the Department of Philosophy should attend my wedding if they want me to be lenient in assessing their exam
  • If you do not agree with my political opinions, you will not graduate from this university.


The Appeal to Pity (argumentum ad misericordiam)

Literally, misericordiam means “a pitying heart”. Thus, this fallacy occurs when the premises of an argument plainly relies on mercy, generosity, altruism, and so on. For instance, a lawyer might use the special circumstances of his client (an offender) to justify leniency in punishment. In short, when the lawyer emphasizes the unfortunate consequences that will befall his client instead of looking at the overwhelming proof of his guilt, he has committed this fallacy. The following passages commit this fallacy:

  • I am a single parent, solely responsible for the financial support of my children. If you give me this traffic ticket, I will lose my license and be unable to drive to work. If I cannot work, my children and I will become homeless and may starve to death. Therefore, you should not give me this traffic ticket (Offor 2012: 42).
  • I implore the jury to temper justice by mercy. Though my client, barely eighteen, is accused of killing his mother and father with an axe, I plead for leniency on the grounds that he is an orphan.
Definition and the classification of fallacy

The Appeal to Emotion (argumentum ad populum)

This fallacy is committed when, instead of using evidence and rational argument, you appeal to the emotion of the people to win their assent to a conclusion. The appeal to emotion, therefore, relies on expressive language and other devices to arouse strong feelings that may lead an audience to accept its conclusion. This fallacy is a device often used by politicians, propagandists, is common in commercial advertising. The following example explains this fallacy:

  • The wisest men and women in Yoruba history have all been interested in Ifa. Obas, queens and regents of all epochs in Yoruba land have believed in it and have guided the affairs of their people by it. Therefore those who say that Ifa is not a science are mistaken.
  • In the last presidential campaign, a mammoth crowd welcomed Goodluck Jonathan in each of the northern zones. In the last election, he led the other presidential candidates with very wide margins and became president. Therefore, those who accuse Jonathan of financial misappropriation are not sincere.


The Appeal to Inappropriate Authority (argumentum ad verecundiam)

This fallacy arises when we appeal to the opinions of someone who in fact does not have any legitimate claim to authority in the matter at hand. In other words, it “involves the mistaken supposition that there is some connection between the truth of a proposition and some feature of the person who asserts or denies it For instance, it would be  fallacious to appeal to the opinions of a movie star on whether taking a brand of beer is good for the body or not. Someone with expertise in food nutrition would be the appropriate authority. Thus, “when the truth of some proposition is asserted on the basis of the authority of one who has no special competence in that sphere, the appeal to inappropriate authority is the fallacy committed Consider these examples:

  • Philip Ogundeji, a Professor of Linguistics and African Languages at the University of Ibadan, believes that the stars revolve around the earth in a perfect circle. Therefore, the stars revolve round the earth in a perfect
  • But can you doubt that air has weight when you  have the clear testimony of Aristotle affirming that all the elements have weight including air, and excepting onlyfire?


Argument Against the Man or Person (argumentum ad hominem)

This is a fallacy in which the argument relies on an attack against the person taking a position. In other words, when the thrust of an argument is directed at someone who is defending a conclusion in dispute (and not the conclusion itself), the fallacy committed id ad hominem. There are two major forms of the argument ad hominem, namely, the ‘abusive’ and the ‘circumstantial’. The ‘abusive’ variety of ad hominem is committed when one attacks the person who made an assertion, instead of giving reasons why the assertion should not be accepted. The ‘circumstantial’ occurs when one argues against the circumstance of the opponent, instead of assessing the dispute in question. Consider the following examples:


  • Brown’s arguments for premarital sex should be dropped because he is a womanizer.
  • Darwin’s thesis of natural selection should be discarded as a work of fiction because he is a


  • Father John should accept my position that abortion should be abolished because this is compatible with his faith as a Catholic.
  • Former President Bush wouldn’t approve of President Obama’s economic policies because he is a Republican.


Appeal To Ignorance (argumentum ad ignorantiam)

This fallacy is committed when one posits that a proposition is true simply because it has not been proved false or that it is false because it has not been proved true. Bello  adds that “this mode of argument is commonly used to against the existence of witches, spirits, and other forms of extraordinary’ phenomena”. The following passages commit this fallacy:

  • No one has conclusively proven that there is no intelligent life on the moons of Jupiter. Therefore, there is intelligent life on the moons of Jupiter.
  • The alarmists have not succeeded in proving that the toxic and radioactive materials dumped at Koko (Delta state) are dangerously harmful to human life. The materials are therefore perfectly safe.


Irrelevant Conclusion (ignoratio elenchi)

Ignoratio elenchi translates to “mistaken proof” and is a type of fallacy in which the premises provide justification or grounds for a different conclusion than the one that is proposed. It tries to establish the truth of a proposition with premises which actually provide support for an entirely different conclusion. The following are examples of this fallacy:

  • The Golden rule is basic to every system of ethics ever devised. Everyone accepts it in some form or other. Therefore, people’s lives are guided by legislations.
  • Capitalism is desirable. For at one time all utilities were state-owned; now more and more of them are being commercialised or privatised. The Structural Adjustment Programme (SAP), moreover, is based on capitalist principles. We are well on our way to full-blown capitalism and its complete triumph is inevitable (Bello 2007: 51).


Black-or-White Fallacy

Also referred to as Fallacy of False Alternatives, this fallacy is committed when it is falsely assumed in an argument that only two alternatives or positions are possible in regards to a certain issue or when the possibility of a third alternative to the two already allowed is ignored. For example:

  • He who is not a PDP member is against Jonathan’s regime

Oshiomole is not a PDP member

He is therefore against Jonathan’s regime.

  • He who does not preach the Word of God is an anti- Christ

Bisala does not preach the Word of God Therefore, he is an anti-Christ.

We Believe This Article Was Helpful, Don’t Hesitate To Share This Information With Your Friends On Facebook, Twitter, Whatsapp and Google plus.
Disclaimer: The contents on this site is provided as an information guide only. They are intended to enhance public access to information about Education and other Endeavors. While every effort is made in preparing good information, no responsibility is accepted by or on behalf of this site for any errors, omissions or misleading statements. Although every effort is made to ensure the reliability of this site.

Copyright: Contents on this website may not be republished, reproduced, redistributed either in whole or in part without due permission or acknowledgement. All contents are protected by DMCA.
The content on this site is posted with good intentions & information purposes. If you own this content & believe your copyright was violated or infringed, make sure you contact us via This Means to file a complaint & actions will be taken immediately.

Leave a Reply