According to whether there is overlap between the extensions of concepts, they can be divided into two categories: compatible relationship and incompatible relationship.
There may be four kinds of compatible relationships, namely, the same relationship (same relationship or overlapping relationship), true inclusion relationship (genus relationship), true inclusion relationship (species relationship) and cross relationship.
There may be two incompatible relationships, namely, contradictory relationship and antagonistic relationship.
Euler diagram is as follows
2. Briefly describe the logical method of defining words (or concepts)
The logical methods of defining concepts include definition, division, restriction and generalization.
Definition is a logical method to reveal the connotation of concepts. In the logical structure, the definition consists of defined item, defined item and defined joint item, and its structural form is Ds is Dp. The common method of definition is the logical method of "genus plus species difference" For example, "commodity is a labor product for exchange" is a definition. "Commodity" is the definition item, "labor products for exchange" is the definition item, and "Yes" is the definition item. In the definition, "labor product" is "genus" and "used for exchange" is "species difference".
Division is a logical method to clarify the extension of a concept, that is, to divide the objects reflected by a concept into several small categories. Division consists of three elements: parent, child and division basis. There are many methods of segmentation, such as once segmentation and continuous segmentation. For example, "students can be divided into college students, middle school students and primary school students" is a division, "students" is the "mother item" and "college students, middle school students and primary school students" is the "child item", and the education level is the basis for the division.
Restriction is a logical method to narrow the extension of a concept by increasing its connotation. For example, "Bridge → Arch Bridge → Stone Arch Bridge → Zhao Zhouqiao" is a series of restrictions.
Generalization is a logical method to expand the concept extension by reducing the connotation of the concept. For example, "novel → literary works" is a generalization.
3. Briefly describe the definition, elements and basic rules of syllogism reasoning.
Syllogism is indirect reasoning based on two nature propositions containing the same item and a new nature proposition.
A syllogism consists of three propositions. Any valid syllogism has and can only have three different terms. In the same syllogism, each term appears twice. The subject of the conclusion is called the minor term, the predicate of the conclusion is called the major term, and the term that appears in the premise but does not appear in the conclusion is called the middle term. The premise containing small events is called "minor premise", and the premise containing big events is called "major premise".
The basic rules of syllogism are as follows (different textbook items are different):
1, an effective syllogism can only have three different terms;
2. At least once on the premise of GAI;
3. Items that are not GAI in the premise may not be Gai in the conclusion;
4. Two negative premises cannot lead to a conclusion;
5. If one of the premises is negative, the conclusion is also negative;
6. If the conclusion is negative, one of the premises must be negative;
7. The premise of two special names cannot be concluded;
8. If one of the premises is special, then the conclusion is also special.
(Some textbooks don't take 1 as the basic rule, while others combine Article 5 and Article 6 into one. )