Types of Informal Fallacy

From Dictionary of Philosophy

By Peter A. Angeles

Black-and-White Fallacy- arguing with sharp (black-and-white) distinctions despite any factual or theoretical support for them, or by classifying any middle point between extremes as one of the extremes. Ex. "If he is not an atheist then he is a decent person." "He is either a conservative or a liberal." "He must not be peace-loving, since he participated in picketing the American embassy."

Fallacy of argumentum ad baculum (arguing from power or force).- The Latin means "an argument according to the stick," "argument by means of the rod," "argument using force." Arguing to support the acceptance of an argument by a threat, or use of force. Reasoning is replaced by force, which results in the termination of logical argumentation, and elicits other kinds of behavior (such as fear, anger, reciprocal use of force, etc.)

Fallacy of argumentum ad hominem (argument against the man).-The Latin means "argument to the man." Arguing against, or rejecting a person's views by attacking or abusing his personality, character, motives, intentions, qualifications, etc., as opposed to providing evidence why the views are incorrect. Ex. "What John said should not be believed because he was a Nazi sympathizer."

Fallacy of argumentum ad ignorantiam (argument from ignorance).- The Latin means "argument to ignorance." Arguing that something is true because no one has proved it to be false, or arguing that something is false because no one has proved it to be true. Ex. a: Spirits exists since no one has as yet proved that there are not any. b: Spirits do not exist since no one has as yet proved their existence. Also called the appeal to ignorance: the lack of evidence (proof) for something is used to support its truth.

Fallacy of argumentum ad misericordiam (argument to pity).- Arguing by appeal to pity in order to have some point accepted. Ex. "I've got to have at least a B in this course, Professor Angeles. If I don't, I won't stand a chance for medical school, and this is my last semester at the university." Also called the appeal to pity.

Fallacy of argumentum ad personam (argument to personal interest).- Arguing by appealing to the personal likes (preferences, prejudices, predispositions, etc.) of others in order to have an argument accepted.

Fallacy of argumentum ad populum (argument to the people). Also the appeal to the gallery, appeal to the majority, appeal to what is popular, appeal to popular prejudice, appeal to the multitude, appeal to the mob instinct. Arguing in order to arouse an emotional, popular acceptance of an idea without resorting to a logical justification of the idea. An appeal is made to such things as biases, prejudices, feelings, enthusiasms, attitudes of the multitude in order to evoke assent rather than to rationally support the idea.

Fallacy of argumentum ad verecundiam (argument to authority or veneration). Appealing to authority (including customs, traditions, institutions, etc.) in order to gain acceptance of a point at issue and/or appealing to the feelings of reverence or respect we have of those in authority, or who are famous. Ex. "I believe that the statement ‘You cannot legislate morality’ is true, because President Eisenhower said it."

Fallacy of accent. Sometimes classified as an ambiguity of accent. Arguing to conclusions from undue emphasis (accent, tone) upon certain words or statements. Classified as a Fallacy of ambiguity whenever this emphasis creates and ambiguity or amphiboly in the words or statements used in the argument. Ex. "The queen cannot but be praised."

Fallacy of accident. Also called by its Latin name a dicto simpliciter ad dictum secundum quid. Applying a general rule or principle to a particular instance whose circumstances by "accident" do not allow the proper application of that generalization. Ex. "It is a general truth that no one should lie. Therefor, no one should lie if a murderer at the point of a knife asks you for information you know would lead to a further murder." Also, the error in argumentation of applying a general statement to a situation to which it cannot, and was not necessarily intended to, be applied.

Fallacy of ambiguity. An argument that has at least one ambiguous word or statement from which a misleading or wrong conclusion is drawn.

Fallacy of amphiboly. Arguing to conclusions from statements that are amphibolous—ambiguous because of their syntax (grammatical construction). Sometimes classified as a fallacy of ambiguity.

Fallacy of begging the question. Arriving at a conclusion from statements that themselves are questionable and have to be proved but are assumed true. Ex. The universe has a beginning. Every thing that has a beginning has a beginner. Therefore the universe has a beginner called God. This assumes (begs the question) that the universe does indeed have a beginning and also that all things that have a beginning have a beginner. Also, assuming the conclusion or part of the conclusion in the premises of an argument. Sometimes called circular reasoning, vicious circularity, vicious circle fallacy. Ex. "Everything has a cause. The universe is a thing. Therefore, the universe is a thing that has a cause. Cf. Petitio principii. Also, arguing in a circle. One statement is supported by reference to another statement which statement itself is supported by reverence to the first statement. Ex. "Aristocracy is the best form of government because the best form of government is that which has strong aristocratic leadership."

Fallacy of complex question (or loaded question). Asking questions for which either a yes or a no answer will incriminate the respondent. The desired answer is already tacitly assumed in the question and no qualification of the simple answer is allowed. Ex. "Have you discontinued the use of opiates?" Also, asking questions that are based on unstated attitudes or questionable (or unjustified) assumptions. These questions are often asked rhetorically of the respondent in such a way as to elicit an agreement with those attitudes or assumptions from others. Ex. "How long are you going to put up with this brutality?"

Fallacy of composition. Arguing that what is true of each part of a whole is also (necessarily) true of the whole itself, or that what is true of some parts of a whole is also (necessarily) true of the whole itself. Ex. "Each member (or some members) of the team is married; therefore the team also has (must have) a wife." Inferring that a collection has certain characteristics merely on the basis that its parts have them erroneously proceeds from regarding the collection distributively to regarding it collectively.

Fallacy of consensus gentium. Arguing that an idea is a true on the basis that the majority of people believe it and/or that it has been universally held by all men at all times. Ex. "God exists because all cultures have had some concept of a God."

Fallacy of converse accident. Sometimes converse fallacy of accident. Also called by its Latin name a dicto secundum quid ad dictum simpliciter. The error of generalizing from atypical or exceptional instances. Ex. "A shot of warm brandy each night helps older people relax and sleep better. People in general ought to drink warm brandy to relieve their tension and sleep better."

Fallacy of division. Arguing that what is true of a whole is also (necessarily) true of its parts and/or also true of some of its parts. Ex. "The community of Pacific Palisades is extremely wealthy. Therefore, every person living there is (must be) extremely wealthy (or therefore Adam, who lives there, is [must be] extremely wealthy)." Inferring that the parts of a collection have certain characteristics merely on the basis that their collection has them erroneously proceeds from regarding the collection collectively to regarding it distributively.

Fallacy of equivocation. An argument in which a word is used with one meaning (or sense) in one part of the argument and with another meaning in another part. A common example: "The end of a thing is its perfection; death is the end of life; hence, death is the perfection of life."

Fallacy of non causa pro causa. The Latin may be translated as "there is no cause of the sort which has been given as the cause." Believing that something is the cause of an effect when in reality it is not. Ex. "My incantations caused it to rain." Also, arguing so that a statement appears unacceptable because it implies another statement that is false (but in reality is not).

Fallacy of post hoc ergo propter hoc. The Latin means "after this therefore the consequence (effect) of this," or "after this therefore because of this." Sometimes simply fallacy of false cause. Concluding that one thing is the cause of another simply because it precedes it in time. A confusion between the concept of succession and that of causation. Ex. "A black cat ran across my path. Ten minutes later I was hit by a truck. Therefore, the cat’s running across my path was the cause of my being hit by a truck."

Fallacy of hasty generalization. Sometimes fallacy of hasty induction. An error of reasoning whereby a general statement is asserted (inferred) based on limited information, inadequate evidence, or an unrepresentative sampling.

Fallacy of ignoratio elenchi (irrelevant conclusion). An argument that is irrelevant; that argues for something other than that which is to be proved and thereby in no way refutes (or supports) the points at issue. Ex. A lawyer is defending his alcoholic client who has murdered three people in a drunken spree argues that alcoholism is a terrible disease and attempts should be made to eliminate it. Ignoratio elenchi is sometimes used as a general name for all fallacies that are based on irrelevancy (such as ad baculum, ad hominem, ad misericordiam, ad populum, ad verecundiam, consensus gentium, etc.)

Fallacy of inconsistency. Arguing from inconsistent statements, or to conclusions that are inconsistent with the premises. See the fallacy of tu quoque below.

Fallacy of irrelevant purpose. Arguing against something on the basis that it has not fulfilled its purpose (although in fact that was not its intended purpose).

Fallacy of "is" to "ought." Arguing from premises that have only descriptive statements (is) to a conclusion that contains an ought, or a should.

Fallacy of limited (or false) alternatives. The error of insisting without full inquiry or evidence that the alternatives to a course of action have been exhausted and/or are mutually exclusive.

Fallacy of many questions. Sometimes fallacy of the false question. Asking a question for which a single and simple answer is demanded yet the question (a) requires a series of answers, and/or (b) requires answers to a host of other questions, each of which should be answered separately. Ex. “Have you left school?”

Fallacy of misleading context. Arguing by misrepresenting, distorting, omitting, or quoting something out of context.

Fallacy of prejudice. Arguing from a bias or emotional identification or involvement with an idea (argument, doctrine, institution, etc.).

Fallacy of red herring. Ignoring a criticism of an argument by changing attention to another subject. Ex. “You believe in abortion, yet you don’t believe in the right-to-die-with-dignity bill before the legislature.”

Fallacy of slanting. Deliberately omitting, deemphasizing, or overemphasizing certain points to the exclusion of others in order to hide evidence that is important and relevant to the conclusion of an argument and that should be taken account of in an argument.

Fallacy of special pleading. Accepting an idea or criticism when applied to an opponent’s argument but rejecting it when applied to one’s own argument. Also, rejecting an idea or criticism when applied to and opponent’s argument but accepting it when applied to one’s own.

Fallacy of straw man. Presenting an opponent’s position in as weak or misrepresented a version as possible so that it can be easily refuted. Ex. “Darwinism is in error. It claims that we are all descendants from an apelike creature, from which we evolved according to natural selection. No evidence of such a creature has been found. No adequate and consistent explanation of natural selection has been given. Therefore, evolution according to Darwinism has not taken place.”

Fallacy of the beard. Arguing that small or minor differences do not (or cannot) make a difference, or are not ( or cannot be) significant. Also, arguing so as to find a definite point at which something can be named. For example, insisting that a few hairs lost here and there do not indicate anything significant about my impending baldness; or trying to determine how many hairs a person must have before he can be called bald (or not bald).

Fallacy of tu quoque (you also). Presenting evidence that a person’s actions are not consistent with that for which he is arguing. Ex. “John preaches that we should be kind and loving. He doesn’t practice it. I’ve seen him beat up his kids.” Also, showing that a person’s views are inconsistent with what he previously believed and therefore (1) he is not to be trusted, and/or (2) his new view is to be rejected. Ex. “Judge Farmer was against marijuana legislation four years ago when he was running for office. Now he is for it. How can you trust a man who has changed his mind on such an important issue? His present position is inconsistent with his earlier view and therefore should not be accepted.” Sometimes related to the fallacy of two wrongs make a right. Ex. The Democrats for years used illegal wiretapping; therefore the Republicans should not be condemned for illegal wiretapping.

Fallacy of unqualified source. Using as support in an argument a source of authority that is not qualified to provide evidence.

Gambler’s fallacy. Arguing that since, for example, a penny has fallen tails ten times in a row then it will fall head the eleventh time. Also, arguing that since, for example, an airline has not had an accident for the past ten years, it is then soon due for an accident. The gambler’s fallacy rejects the assumption in probability theory that each event is independent of its previous happening. The chances of an event happening are always the same no matter how many times that event has taken place in the past. Given those events happening over a long enough period of time then their frequency would average out to ½. Sometimes referred to as the Monte Carlo Fallacy (a generalized form of the gambler’s fallacy): The error of assuming that because something has happened less frequently than expected in the past, there is an increased chance that it will happen soon.

Genetic fallacy. Arguing that the origin of something is identical with that from which it originates. Ex. “Consciousness originates in neural processes. Therefore, consciousness is (nothing but) neural processes.” Sometimes referred to as the nothing-but fallacy, or the Reductive Fallacy. Also, appraising or explaining something in terms of its origin, or source, or beginnings. And, arguing that something is to be rejected because its origins are known and/or are suspicious.

Pragmatic fallacy. Arguing that something is true because it has practical effects upon people: it makes them happier, easier to deal with, more moral, loyal, stable. Ex. “An immortal life exists because without such a concept men would have nothing to live for. There would be no meaning or purpose in life and everyone would be immoral.”

Bonus fallacies:

The naturalistic or reductive fallacy. Also the “nothing but” fallacy. 1. Erroneously believing (a) that a complex whole is nothing but, or identical with, its parts or causes, and/or (b) that a complex whole can be entirely explained in terms of the description of its parts or causes. Ex. Mental states are caused by neural processes. Neural processes can exist without the occurrence of mental states. Therefore mental states are nothing but neural processes. 2. The error of explaining a phenomenon and regarding its explanation as being real rather than the phenomenon being explained. See item 31. above.

The pathetic fallacy. Incorrectly projecting (attributing) human emotions, feelings, intentions, thoughts, traits upon events or objects which do not possess the capacity for such qualities.