Many people have a misunderstanding that logic is boring and difficult to learn. This is a psychological obstacle to learning logic well. In fact, logic is not boring at all. Although the objects of logic research are abstract formal structures and laws, they are all used all the time in daily thinking and can be encountered everywhere in daily language materials. Logic is closely related to daily life, study and work. It is not only useful, but also lively and interesting. As for logic, it depends on how to understand it, because logic itself has different branches and levels. Just like mathematics, many contents in advanced mathematics may be difficult for middle school students or liberal arts students, but arithmetic, algebra and plane geometry are not so difficult. This book introduces general logic. Its position in logic science is equivalent to elementary algebra and plane geometry in mathematics. Is the basic logic. It is not difficult for a person who already has a knowledge base in middle school to learn logic well.

Of course, it takes some time to learn any subject well. There are some obvious differences between logic and other disciplines (especially other courses of liberal arts). Learning logic should pay attention to the following questions:

1. We should pay full attention to the function of formulas and learn to analyze problems formally.

There are many formulas in logic, such as "all s are p", "p or q", and some formulas also contain some special symbols, such as ∧, ∨, → and so on, which is an important feature of logic. Some people get bored when they see these formulas when they are learning logic, hoping to avoid these formulas and learn logic. This idea is naive. Because the main research object of logic is the logical form of thinking, and the logical form can only be accurately expressed by means of formulas, canceling these formulas is equivalent to canceling logic itself. Therefore, learning logic can not only avoid formulas, but also focus on these formulas, learn to abstract their logical forms from concrete thinking, and formally analyze them. For example, there is such a logic test:

"All criminal acts are illegal, so all illegal acts are criminal acts." Is this reasoning correct? Why?

Some students replied: "incorrect, because only those illegal acts that are very harmful to society and should be punished for violating the criminal law constitute crimes." This answer certainly does not meet the requirements, because it is not a test of legal common sense, but a test of logical knowledge. This test question actually asks whether the enumerated reasoning form is correct, that is, whether the previous judgment can be logically deduced from the latter judgment, rather than whether the latter judgment itself conforms to the jurisprudence. If you master the relevant logical formulas skillfully, you can quickly abstract the logical form of the original reasoning "all S are P, so all P are S", and then analyze whether this reasoning form is correct. Only in this way can the answer meet the answer requirements.

Try to understand the basic principles and don't be satisfied with rote learning.

Of course, logic also has some basic knowledge to remember, but compared with other disciplines, there are relatively few things to remember. Some people learn logic and are satisfied with memorizing definitions, rules and formulas, but they don't really understand it, let alone use it. As a result, their logic is not good. Some people have memorized their logic textbooks, but their grades are still not ideal, because most logic questions are applied and the answers can't be called directly from memory. This also shows that you can't learn logic by rote.

Learning logic focuses on understanding. We should ask more questions about the definitions of some basic concepts and the main rules of reasoning, and we should not only "know what it is" but also "know what it is" in order to grasp the essence of these logical principles. In addition, we should also pay attention to the internal relations between the contents of each part. For example, the structural form of a judgment determines its logical nature, and the logical nature determines the reasoning rules based on it, and the reasoning rules determine its effective formula and the logical mistakes often made when using this reasoning, and so on. If we grasp the internal relationship between these contents, we can get twice the result with half the effort, which is impossible for mechanical memory.

3. We should conscientiously complete a certain number of exercises and pay attention to integrating theory with practice.

Logic is an instrumental subject. In order to transform the learned logic knowledge into the ability to apply logic, we must pay attention to integrating theory with practice.

Logic textbooks are generally accompanied by a certain number of exercises to help readers understand and apply relevant logic knowledge. Completing these exercises is a necessary part of learning logic. The content of exercises generally involves the practice of specific thinking, and completion is the minimum requirement of integrating theory with practice. In addition, readers should always use the logical knowledge they have learned to guide their thinking activities and language expression (including speaking, writing, debating, giving speeches, etc.). ), and analyze the logical structure, thinking methods and logical errors of various language materials you see or hear every day, so as to learn to use logical knowledge flexibly and really improve your thinking ability and expression level.

-From Logic (Yang Shusen), page 15- 17, Higher Education Press, April 20 10.