logical fallacy

(noun)

A fallacy; a clearly defined error in reasoning used to support or refute an argument, excluding simple unintended mistakes.

Examples of logical fallacy in the following topics:

  • Logical Fallacies

    • A fallacy is an error in reasoning; there are two basic categories of fallacies--formal and informal.
    • A fallacy is an error in reasoning.
    • By applying formal logic to the syllogism in the example, the conclusion is still valid.
    • In informal logic and rhetoric, a fallacy is usually an error in reasoning often due to a misconception or a presumption.
    • Some of the more frequent common logical fallacies are:

  • Defining Emotional Appeal

    • An emotional appeal is directed to sway an audience member's emotions and uses the manipulation of the recipient's emotions rather than valid logic to win an argument.
    • An emotional appeal uses emotions as the basis of an argument's position without factual evidence that logically supports the major ideas endorsed by the presenter.
    • Emotional appeal is a logical fallacy, whereby a debater attempts to win an argument by trying to get an emotional reaction from the opponent and audience.
    • In debating terms, emotional appeals are often effective as a rhetorical device, but are generally considered naive or dishonest as a logical argument, since they often appeal to the prejudices of listeners rather than offer a sober assessment of a situation.
    • As with children, cute animals override most people's logic.

  • External Benefits: Influence the World Around You

    • The same logic exists in public speaking situations.
    • Trained speakers know how to recognize sound logic, reasoning, and ethical appeals.
    • A critical listener is less likely to be persuaded by unsound logic and fallacies or to take action that is not in his or her best interest.

  • Ethical Usage: Considering Other Viewpoints

    • When the process is flawed, there may be a statistical fallacy.
    • Though many researches, scientists, pollsters, and investigators do their best to avoid fallacies, the possibility always exists that one may be proven.
    • Since it is very easy to unintentionally lie by not explaining all the nuances of the evidence and it is very easy to use evidence that may contain fallacies, it is the duty of every speaker to consider the viability of opposing viewpoints before rejecting them.

  • Using Different Kinds of Appeals

    • Evidential appeals are formed by defining the evidence and then explaining how the evidence must logically prove that a certain conclusion must be true.
    • Then the scientist must explain how that evidence logically leads to a consequence that supports his/her proposal.

  • Types of Supporting Materials

    • There are many types of supporting materials, some of which are better suited for logical appeals and some for emotional appeals.
    • Facts and figures are necessary for logical appeals .

  • Organizing and Outlining the Speech

    • If you put all of your research notes and thoughts onto notecards, it is particularly helpful to lay them out in front of you and begin to organize your points and sub-points in ways that make the most logical sense.
    • Building on the idea of your thesis as machine, you may present your overall, broad idea, then break it down into smaller, logical steps to reach that big idea.
    • On the other hand, you can dilute the complexity of a broad idea by breaking it down into smaller, logical pieces of information.

  • Deploying a Rational Appeal

    • A rational appeal uses logical arguments and factual evidence to persuade individuals.
    • A rational appeal uses logical arguments and factual evidence to persuade individuals that whatever thesis you are supporting is viable and likely to result in the obtainment of goals.
    • Invention is how you formulate arguments based on logos--rational appeal or logic.
    • When you appeal to reason you use logically constructed arguments using your evidence to persuade your audience to agree with you.
    • Arguments from reason (logical arguments) have some advantages, namely that data are (ostensibly) difficult to manipulate, so it is harder to argue against such an argument; and such arguments make the speaker look prepared and knowledgeable to the audience, enhancing ethos.

  • Different Lines of Reasoning

    • Consider these simple logical statements, known as syllogisms.
    • Deductive reasoning, also called deductive logic, is the process of reasoning from one or more general statements, laws, or principles regarding what is known, in order to reach a logically certain conclusion.
    • If the rules and logic of deduction are followed, this procedure ensures an accurate conclusion.
    • The first premise states that all objects classified as "men" have the attribute "mortal. " The second premise states that "John" is classified as a "man"—a member of the class or group of "men. " The conclusion then states that "John" must be "mortal" because he inherits this attribute from his classification as a "man. " If both premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion of the argument follows by logical necessity.

  • Ethical Usage

    • When you stir sympathy in your listeners, you encourage them to identify with your message on a visceral level, bypassing intellectual filters, such as skepticism and logic.
    • However, this may be unethical because you are not allowing your listeners to logically consider your argument and rationally determine how they would react to your argument in absence of an emotional appeal.
    • Therefore, be sure to substantiate your emotional appeal with both logic and facts.