Ad hominem, short for argumentum ad hominem, is a term that refers to several types of arguments, most of which are fallacious. Typically this term refers to a rhetorical strategy where the speaker attacks the character, motive, or some other attribute of the person making an argument rather than attacking the substance of the argument itself. This avoids genuine debate by creating a diversion to some irrelevant but often highly charged issue. The most common form of this fallacy is "A makes a claim x, B asserts that A holds a property that is unwelcome, and hence B concludes that argument x is wrong".
A false dilemma, also referred to as false dichotomy or false binary, is an informal fallacy based on a premise that erroneously limits what options are available. The source of the fallacy lies not in an invalid form of inference but in a false premise. This premise has the form of a disjunctive claim: it asserts that one among a number of alternatives must be true. This disjunction is problematic because it oversimplifies the choice by excluding viable alternatives, presenting the viewer with only two absolute choices when in fact, there could be many.
Argument from ignorance, also known as appeal to ignorance, is a fallacy in informal logic. It asserts that a proposition is true because it has not yet been proven false or a proposition is false because it has not yet been proven true. This represents a type of false dichotomy in that it excludes the possibility that there may have been an insufficient investigation to prove that the proposition is either true or false. It also does not allow for the possibility that the answer is unknowable, only knowable in the future, or neither completely true nor completely false. In debates, appealing to ignorance is sometimes an attempt to shift the burden of proof. The term was likely coined by philosopher John Locke in the late 17th century.
A fallacy is the use of invalid or otherwise faulty reasoning in the construction of an argument which may appear to be a well-reasoned argument if unnoticed. The term was introduced in the Western intellectual tradition by the Aristotelian De Sophisticis Elenchis.
An appeal to fear is a fallacy in which a person attempts to create support for an idea by attempting to increase fear towards an alternative. An appeal to fear is related to the broader strategy of fear appeal and is a common tactic in marketing, politics, and media (communication).
Appeal to flattery is a fallacy in which a person uses flattery, excessive compliments, in an attempt to appeal to their audience's vanity to win support for their side. It is also known as apple polishing, wheel greasing, brown nosing, appeal to pride, appeal to vanity or argumentum ad superbiam. The appeal to flattery is a specific kind of appeal to emotion.
An appeal to pity is a fallacy in which someone tries to win support for an argument or idea by exploiting one's opponent's feelings of pity or guilt. It is a specific kind of appeal to emotion. The name "Galileo argument" refers to the scientist's suffering as a result of his house arrest by the Inquisition.
Appeal to emotion or argumentum ad passiones is an informal fallacy characterized by the manipulation of the recipient's emotions in order to win an argument, especially in the absence of factual evidence. This kind of appeal to emotion is irrelevant to or distracting from the facts of the argument and encompasses several logical fallacies, including appeal to consequences, appeal to fear, appeal to flattery, appeal to pity, appeal to ridicule, appeal to spite, and wishful thinking.
Appeal to consequences, also known as argumentum ad consequentiam, is an argument that concludes a hypothesis to be either true or false based on whether the premise leads to desirable or undesirable consequences. This is based on an appeal to emotion and is a type of informal fallacy, since the desirability of a premise's consequence does not make the premise true. Moreover, in categorizing consequences as either desirable or undesirable, such arguments inherently contain subjective points of view.
Reductio ad Hitlerum, also known as playing the Nazi card, is an attempt to invalidate someone else's argument on the basis that the same idea was promoted or practised by Adolf Hitler or the Nazi Party. Arguments can be termed reductio ad Hitlerum if they are fallacious. Contrarily, straightforward arguments critiquing specifically fascist components of Nazism like Führerprinzip are not part of the association fallacy.
Informal fallacies are a type of incorrect argument in natural language. The source of the error is not just due to the form of the argument, as is the case for formal fallacies, but can also be due to their content and context. Fallacies, despite being incorrect, usually appear to be correct and thereby can seduce people into accepting and using them. These misleading appearances are often connected to various aspects of natural language, such as ambiguous or vague expressions, or the assumption of implicit premises instead of making them explicit.
Proof by assertion, sometimes informally referred to as proof by repeated assertion, is an informal fallacy in which a proposition is repeatedly restated regardless of contradiction and refutation. The proposition can sometimes be repeated until any challenges or opposition cease, letting the proponent assert it as fact, and solely due to a lack of challengers. In other cases, its repetition may be cited as evidence of its truth, in a variant of the appeal to authority or appeal to belief fallacies.
Straight and Crooked Thinking, first published in 1930 and revised in 1953, is a book by Robert H. Thouless which describes, assesses and critically analyses flaws in reasoning and argument. Thouless describes it as a practical manual, rather than a theoretical one.
Appeal to the stone, also known as argumentum ad lapidem, is a logical fallacy that dismisses an argument as untrue or absurd. The dismissal is made by stating or reiterating that the argument is absurd, without providing further argumentation. This theory is closely tied to proof by assertion due to the lack of evidence behind the statement and its attempt to persuade without providing any evidence.
In logic, reductio ad absurdum, also known as argumentum ad absurdum or apagogical arguments, is the form of argument that attempts to establish a claim by showing that the opposite scenario would lead to absurdity or contradiction. This argument form traces back to Ancient Greek philosophy and has been used throughout history in both formal mathematical and philosophical reasoning, as well as in debate.
In argumentation theory, an argumentum ad populum is a fallacious argument which is based on claiming a truth or affirming something is good because the majority thinks so.
An argument from authority, also called an appeal to authority, or argumentum ad verecundiam, is a form of argument in which a claim made by an authority on some topic is used as evidence to support one's own claim. Some assert that arguments from authority can be valid or fallacious, depending on circumstances such as whether the putative authority's expertise is relevant to the claim at hand, whether the authority is reliable, and whether there is widespread agreement among authorities on the claim, whereas others claim that appeals to authority are always fallacious.
In logic, an argumentum e contrario, also known as appeal from the contrary, denotes any proposition that is argued to be correct because it is not disproven by a certain case. It is the opposite of the analogy. When analogy is allowed, e contrario is forbidden and vice versa. Arguments e contrario are often used in the legal system as a way to solve problems not currently covered by a certain system of laws. Although it might be used as a logical fallacy, arguments e contrario are not by definition fallacies.
