What Is a Logic Error?

Logical errors generally refer to errors that occur in violation of the requirements of formal logic rules and logical rules in the thinking process. Such as "stealing the concept", "stealing the topic", "contradictory" and so on.

logical error

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Logic has its own laws. No matter what concepts and propositions are used, and what inferences and arguments are made, the basic logic laws must be followed; otherwise, people's thinking will be wrong. Common logical errors include stealing concepts, stealing topics, contradictions, ambiguities, cycle definitions, repetition of the same language, improper juxtaposition of concepts, causality inversion, circular argumentation, and inability to deduce.

Concept and Topic of Logical Error Stealing

In the same thinking process, each thought must be the same as itself, which is the requirement of the same law. It can be expressed by the formula: A is A, and A represents a concept or proposition. A concept reflects what kind of object it is. In the same locale, it cannot reflect both this kind of object and other kinds of objects. A logical error that occurs consciously contrary to the requirements of the same law is logically called a "stolen concept".

Its characteristic is that the meaning of a concept is deliberately unclear, and then a new meaning is inserted into the concept. The business "buy one get one free" promotional advertisement plays the trick of "stealing the concept". The concepts of the two "ones" are very different.

Logical error on the storage device

"One" is what you want to buy, for example: a suit, "one" for "get one", if you understand it as a suit, it is too naive. This "one" may be a tie or a beautiful bag, it will never be a suit.

In terms of the use of concepts, some people do not understand the exact meaning of a concept, and even change the meaning of this concept when they apply it later. This kind of error is called "confusion concept".

The same law also requires that in the same thinking process a proposition affirms what is affirmed, and what is negated is negated. A proposition must have certain "true" and "false" meanings. We call the logical error of unconsciously violating the same law the "transfer thesis." It manifests itself as unconsciously turning another question into a statement or argument in speaking or discourse. For example, if a child speaks, the preface does not match the postscript.

Logical errors that arise consciously against the requirements of the same law on propositions are logically called "stealing topics." Its performance is to consciously change the content of the topic, stealing the beam and changing the pillars, so as to achieve a certain purpose. For example, during the Qing Dynasty, a scholar was sitting on a high platform to read a book. The wind was strong and the pages turned upside down. The student chanted two poems: "The breeze is illiterate, why do you read the book indiscriminately?" Distorting the meaning of the word "Qing", framed scholars to ridicule the Qing court for being illiterate and guilty of gross disrespect.

Paradoxical logic error

In the same thinking process, two contradictory or opposing thoughts cannot be true. One of them must be false. This is a requirement of the law of contradiction. Can be expressed by the formula: A is not non-A, A represents a concept or a proposition. A concept cannot be both it and not it, just like a person cannot be both a person and a person; a proposition cannot affirm both an object and negate it. A logical error that occurs in violation of the law of contradiction is called "contradictory." For example, the joke of the famous Chu man selling spears and shields: He boasted that his shield was very solid and that no one could pass through it; he also boasted that his spear was extremely sharp and could pierce anything. The mistake he made was the classic paradox. Another person says, "For a month, this problem has been entangled with me, and when I am very busy or in a good mood, I temporarily put aside this problem and can no longer think about it." Me ", there will be no" can't think of it "and the speaker will also make a" contradictory "mistake.

Ambiguity in logical errors

Two contradictory thoughts cannot be false, and one of them must be true, which is the requirement of the law of exclusion. Can be expressed by the formula: A or non-A, A represents a concept or a proposition. In the same thinking process, if A does not reflect an object, then non-A reflects that object. For example, if this person is a student, he belongs to either a "secondary school student" or a "non-secondary school student", both of which must be one and cannot be false.

Any proposition either affirms that an object has a certain situation, or denies that an object has such a situation, the two must be one, and two contradictory propositions cannot be false. It requires that in two contradictory thoughts one must clearly recognize that one is true. If this requirement is violated, neither this nor that is recognized, and it is vague, then it will make a "ambiguous" logical error. Because this logical error is characterized by negation of two contradictory ideas, some people call this error "ambiguity."

The Chu people boasted about their spears and shields. When others asked him: how do you use your spear to penetrate your shield? The spear cannot pass through my shield ", which means that he denies both A and non-A. Logically speaking, his silence violates the law of the middle row. In other words, Chu people's answer to any sentence violates the law of contradiction, and a sentence of no answer violates the law of exclusion.

When people lack sufficient understanding of a set of contradictory propositions, they cannot clearly affirm or deny anything, and this situation cannot be diagnosed as a violation of the law of exclusion. For example, "there is life on Mars" and "there is no life on Mars". This is a set of contradictory propositions. Although there must be a truth in it, people cannot express their position clearly. In addition, denying concepts or propositions that are not contradictory relationships does not violate the law of exclusion. Such as "No rain or snow today". "Rain" or "snow" does not have a contradictory relationship, so it can be denied at the same time.

Definition of logical error cycle, same language repetition

Definition is a logical method to reveal the connotation of a concept, that is, to explain the essential attributes of an object in a concise way. The definition consists of three parts: the defined item, the definition item, and the definition joint item. A defined item is a concept that reveals its connotation through definition; a defined item is a concept that is used to reveal the connotation of a defined item; a concept that connects a defined item and a defined item to form a definition is a definition joint item. There are certain rules for the definition, which requires that the definition item cannot directly or indirectly contain the defined item. If you include the defined item directly, you will make a logical error of "same language repetition"; if you indirectly include the defined item, you will make a logical error of "cyclic definition". For example, "a thimble is a rhetoric that uses a thimble technique." To use the "thimble technique" to explain the "thimble" is to say nothing. This definition makes the mistake of "same language repetition". Another example is "if" odd number "is defined as" even number plus one ", then" even number "is the number obtained by" odd number plus one ". The interpretation of "odd" with "even" and "even" with "odd" makes this definition a mistake of "cyclic definition".

Improper juxtaposition of logical error concepts

The concept of juxtaposition belongs to the scope of concept division. The so-called division is a logical method to clarify the concept extension, that is, to divide a generic concept into several sub-concepts based on a certain concept. The division consists of three parts, namely the parent of division, the children of division, and the criteria of division. Among them, the object that is divided is called the parent of division; the concept divided from the parent is called the child of division; the basis of division is usually an attribute of a thing, called the criterion of division. When dividing a genus concept, the sub-concepts obtained after the division can be used as the parent and then divided, which is called "continuous division". No matter how many levels a concept is divided into, each division must follow the division rules, that is, the same standard must be followed in a division. The concepts divided according to different standards cannot be juxtaposed. If the concepts at different levels are juxtaposed in the same division, a logical error of "improper juxtaposition of concepts" will be made. For example, "I like to read foreign works, classical works, novels, prose, Tang poetry, etc." This sentence uses multiple criteria for the classification of works. It juxtaposes concepts divided by different criteria, making the mistake of "improper juxtaposition of concepts."

Logical error causal inversion

Causality is a way of universal connection between things. If the existence of a phenomenon inevitably causes another phenomenon to occur, then the two phenomena have a causal relationship. Among them, the phenomenon that causes a certain phenomenon is called a cause, and the phenomenon that is caused is called a result. Cause and effect are relative in the chain of cause and effect. The result of this matter may be the cause of the other thing, but as far as the cause and effect are concerned, it is absolute. , Can not be the cause. For example, a reformer in Britain in the 19th century found that every hardworking farmer owns at least two cows; those who have no cows are usually those who are lazy. Therefore, his reform approach was that the country gave two cows to every farmer who did not have cows. In this way, the whole country would not have any lazy people. The reformer made the mistake of causal inversion. The farmer owns two cows because of hard work, not because he has two cows. The result of such a reform is naturally that those who are industrious are self-service, and those who are lazy are also lazy.

Argument of Logic Error Cycle

Demonstration is the process of determining the authenticity of another proposition with several real propositions. There is an important principle of argumentation,

Avoiding Group Policy Logic Errors

That is, the authenticity of the argument should not depend on the authenticity of the topic. Whether a topic can be established depends on the authenticity of the argument to prove it. If the authenticity of the argument is in turn based on the authenticity of the topic, it is tantamount to no argument. A logical error made in violation of this rule is called a "circular argument." For example, some people once argued against Copernicus's solar center that they thought the universe was finite. The argument is that the universe orbits the earth one day and night, and the authenticity of the argument relies on the thesis that the universe is finite (because if the universe is infinite, you cannot understand why the infinite universe can orbit itself between day and night The center of the world-the earth moves a week). This makes the mistake of "circular argument".

Logical error

Another important rule of argument is that it is required to proceed logically from the argument, that is, there must be a necessary connection between the argument and the argument.

If you violate this rule, you will make a logical error of "unable to deduce". There are several common situations:

1. Inferential form is incorrect

The argument cannot necessarily be derived from the argument. For example: "He is very shortsighted and must be very smart." There is no necessary connection between "myopia" and "smart", and we can't take my nearsight as a basis to prove whether he is smart. This argument actually uses the following reasoning:

All smart people are nearsighted. He is very nearsighted, so he must be very smart.

This reasoning violates the reasoning rules of syllogism: the middle term must be extended at least once. The expression of "myopia" in both premises is affirmative and neither delays, so this form of reasoning is invalid.

2. Arguments and topics are irrelevant

That is, arguments and topics have nothing to do with content. For example: "He doesn't study hard. Because only by studying hard can he be admitted to the university." In this argument, the argument "no admission to the university" is true, but there is no logically necessary connection between the argument and the topic. The starting point is unable to deduce the conclusion that "he studies without using work".

3. Insufficient arguments

That is, the arguments cited are necessary but not sufficient to determine the authenticity of the topic. For example, "If it rains, the ground will be wet. Now the ground is wet, so it must be raining." "Rain" is a sufficient condition for "wet ground", but "wet ground" is not a sufficient condition for "rain wet", and the conclusion of "rain" cannot be derived based on the condition of "ground wet".

4. False reason

Although the reason for the argument is put forward, it is false. For example, in the fable story "Wolf and Lamb", the reason for the wolf to eat the lamb is that the lamb is standing downstream drinking water and polluting its upstream water. This reason is obviously untenable.