Logic, which takes thinking as the research object, is an ancient and young science.

The essence of logic is mainly embodied in two aspects:

First, instrumental music. Logic is a tool science and a necessary tool for people to think, demonstrate and express correctly. As far as instrumentality is concerned, logic is similar to grammatical rules, and logic is the "grammar" of thinking. In ancient times, logic was the object of study by philosophers, so for a long time before Marxism came into being, logic was always regarded as a branch of philosophy. But its research object is not world outlook and philosophical methodology, so it is not philosophy. The logical forms and laws of logic research are necessary tools for correct thinking. At the same time, logic is also a necessary tool for argument and expression. Anyone who wants to think, demonstrate and express correctly must use effective logical forms and abide by logical laws.

Second, human nature. Logic is different from grammar. Grammar is national and logic is humanistic. Language has the characteristics of convention, and different nationalities and times are different; The use of language is also restricted by context, which is perceptual and so on. Logical form and its laws are summarized from the whole development process of human thinking and are the reflection of objective laws. People of different nationalities, different times and different regions must use common logical forms and abide by common logical laws in order to think correctly.

Second, the significance of learning logic

Generally speaking, logic is one of the necessary tools to express ideas and think about problems. Learning logic can improve the ability of using concepts, putting forward propositions and reasoning, so that when we speak and write articles, when we know things and think about problems, the concepts are clear, the propositions are appropriate, and the logical reasoning and arguments are convincing. The specific role can be summarized as the following aspects:

First, logic is a necessary tool for people to explore new knowledge.

The knowledge provided by logic is an auxiliary tool for us to correctly understand objective things and acquire new knowledge in our study and practice. It can help people effectively introduce new knowledge on the basis of existing knowledge and gain a new understanding of things. Engels pointed out: "Formal logic is also the first method to explore new results from the known to the unknown." ? 1? In cognitive activities, we can apply the known general principles and regular knowledge to individual special things according to logical knowledge, so as to draw new conclusions; We can also sum up general knowledge from known individual knowledge and special knowledge, thus expanding our knowledge. In scientific experiments, we can apply logical knowledge, draw as many new conclusions as possible according to existing scientific theories and known experimental results, and even put forward scientific hypotheses to establish a new scientific theoretical system. If the periodic law of chemical elements was discovered, Mendeleev, a great chemist who worked out the periodic table of elements, inferred that there were three unknown elements besides the 63 elements discovered at that time, namely scandium with the ordinal number of 2 1, gallium with the ordinal number of 3 1 and germanium with the ordinal number of 32. He not only deduced the properties, atomic weights and specific gravities of these elements, but also corrected the specific gravities of gallium wrongly measured by another scientist. Mendeleev's speculation was confirmed by later scientific experiments. This fact of using logical knowledge to make great discoveries can be said to be everywhere in the history of scientific development.

In work and daily life, logic can help us analyze the situation at any time and make correct judgments, so as to make fewer mistakes and achieve success.

Second, logic is a tool to improve our language expression ability.

"Keep your word", people express their thoughts by speaking and writing articles. People's expressive ability is high or low. The reason lies in logic, grammar, rhetoric and human knowledge. Among them, logic is an important aspect. In the process of expressing ideas, in order to improve the effect of expression, people must have clear views, appropriate words, fluent arts and sciences, clear organization and persuasiveness. These are closely related to logical problems. Almost all normal people have an innate ability of thinking and expression, which becomes more and more refined with the increase of social communication and practical experience. However, this ability is inevitably habitual and random. For example, a store has a sign: "When foreign guests go upstairs, customers stop". What should I do if a person is both a foreign guest and a customer? Although this sentence is grammatical, it makes a logical mistake of "cross-juxtaposition", and people with logical training will not make such mistakes in expression. Errors in writing, such as "digression" and "unreasonable arts and sciences", are also caused by violating logical laws. Logic can reveal the law of correct thinking in theory. By studying logic, we can upgrade from spontaneous logical thinking to conscious logical thinking, thus avoiding making logical mistakes and enhancing our expressive ability.

Thirdly, logic is a tool to master and learn new scientific knowledge.

Any science is composed of some basic concepts and propositions, and has an independent category system. The relationship between concepts, the relationship and deduction between propositions, and the proof of a proposition are all based on logical laws. They all have internal logical relations with each other. If we master some logical knowledge, we can consciously analyze its internal structure and the logical relationship between its parts according to the internal relationship of subject knowledge, and then master these scientific knowledge quickly and accurately, so as to achieve the effect of "learning from others" and "learning more".

Fourthly, logic is also a tool for people to identify and expose logical fallacies and refute sophistry.

The correct thinking forms summarized by logic from a large number of human thinking materials and the laws and rules that should be followed in using these thinking forms are the standards for identifying logical fallacies. By studying logic and mastering the correct thinking form and its laws and rules, we can consciously find and avoid logical errors and clarify confused concepts, so as to publicize the truth and educate the masses. For example, someone said, "I'm not a judge, so I'm not studying law!" "For people with logical knowledge, it is not only easy to find mistakes, but also easy to refute ideas. After a little analysis, it is not difficult to find that this statement is actually an omitted syllogism reasoning. Although the premise of this reasoning is true, the conclusion is false. Because it violates the syllogism reasoning rule that "the item in the premise is not GAI, and the conclusion can't be GAI", it makes the logical mistake of "expanding the big item".

Learning and mastering logical principles can not only help you not to make or make fewer logical mistakes, but also effectively analyze the fallacies of others and refute their sophistry. For example, Tom saw an advertisement in the newspaper. The advertisement is a beautiful bicycle, which costs 55.99 pounds. He went to the shop to see the bicycle, and then said to the manager, "Why doesn't this car have a light?" And the car in the advertisement has lights? The manager said, "The advertised car price does not include lights." If you want to buy a car, you have to add the price of the lamp. "Tom was very angry." This is very dishonest. Since the lamp is advertised, it should be included in your price. "Yes, sir," said the manager, "in our advertisement, there is still a beautiful girl sitting on the bus, but when we sell bicycles, we don't provide a girl for the buyer! "The manager is obviously quibbling about his fraud, and the method used is' mechanical analogy', because the lamp is an accessory of the car and the girl is not an accessory of the car. The two can't be compared, and it is easy to expose his sophistry logically.

Above, the function of logic is only illustrated from four aspects. In fact, its role goes far beyond these aspects. We admit that logic does play a great role as a tool of human thinking, but we can't exaggerate its role too much. It should be said that logic only helps people to think correctly from the logical form of thinking. As for judging whether the content of thinking is true or not, there is nothing we can do, which depends on other knowledge to solve. Only by combining logical knowledge with other related scientific knowledge can we ensure people's correct thinking.

Third, the method of learning logic.

This course is both boring and abstract for beginners. However, as long as you are willing to work hard and use the right method, you can master its content well. The basic method of learning logic is to integrate theory with practice. Specifically, it is:

First of all, we should master the basic theory of logic and understand and master the main definitions, laws, rules and formulas. The key contents of each chapter should be understood repeatedly and memorized on the basis of understanding.

Second, we should do exercises seriously. In order to facilitate everyone to review and consolidate what they have learned, there are thinking questions and thinking training questions at the end of each chapter. Doing exercises carefully can help beginners master relevant contents and consolidate their logical knowledge such as definitions, formulas and rules.

Third, it should be applied in combination with practical problems in daily thinking and expression. This can not only consolidate theoretical knowledge, improve application ability, but also realize the happiness of learning and improve interest in learning.

Finally, it is very important to choose the right teaching materials. I suggest you read the third edition of Logic edited by Jiang Quanji and Chi Weidong. This book is easy to understand, published by Higher Education Press, and is the largest circulation textbook in China.