What are the classic examples of fallacy?

And then the second point. Logic derives examples. There are two requirements:

Be prepared for the first example. Whether it is accumulation in life or preparation before the game, examples of fallacy cannot be thought of on the spot, otherwise it is very likely to be extreme. Second, keep the examples simple.

What is simple, is to go into simple terms, understand at a glance, don't cite examples with logical reasoning others think for a long time, this is not good. At this point, the fallacy is basically finished. And then I say more, when the first point can be done, a lot of debate techniques that are more powerful than the fallacy can be launched, and you can only use this technique if you don't reduce the fallacy, so use this technique, that's called Shinobi.

There are a lot of techniques that can be used, and then I chose this technique, which is called Shinobi.

This can be tested in the following ways: First, is there any essential similarity between the fallacy method we use and what the other person is talking about? (If the other side says that socialism is not applicable in some countries, we think that the other side is saying that socialism is not good, but in fact we have expanded the scope, and our fallacy is a failure) Second, is the logic we use reasonable?

For example, we think that learning is more important than practice for college students, but is your argumentation process clear? Are you logically valid? Logical irrationality is the easiest way to overturn the fallacy).

Classic examples of fallacies include, but are not limited to:

1. Case 1:

During the Warring States period in our country, there was a man in the state of Chu who sold spears and shields.

He raised his spear and said, "This is the sharpest grass in the world, and the strongest shield can pierce through it"!

The onlookers were also amazed!

Then he put down the grass in his hand, picked up his shield and said: "This is the strongest shield in the world, and the sharpest grass cannot pierce it"!

A melon-eating crowd couldn't help but ask: "What will be the result of stabbing your shield with your grass?" ”

The people of Chu were immediately dumbfounded, unable to solve his problems. The onlookers also burst into laughter!

This is where the idiom "self-contradiction" comes from.

2. Case 2:

A said, "The older a person gets, the more he will understand." ”

B retorts with the fallacy: "If the older you get, the more you know, then those centenarians are the most learned people in the world."

3. Case 3:

A: "How can something that is not noble be popular?" So popular music is noble music. ”

B retorted: "So, the popular ** is also noble? ”

Analysis: "How can something that is not noble be popular?" This sentence is equivalent to saying that "whatever is popular is noble." B assumes that it is true, and derives that "the popular ** is also noble".

This is a very absurd result.

4. Case 4:

A congregant came to the church and said to the priest: "I am religious, but I don't know what God can help me." ”

The believer worriedly said, "My neighbor is also religious, and if I pray to God for rain and he prays for a sunny day, what will God decide?" ”

The priest was speechless!

5. Case 5:

The ancient Greek philosopher Plato once defined "man": "Man is a two-legged animal without feathers".

So one of his students stripped off a rooster and laid it in front of everyone.

The crowd laughed!

For example, the results of the conditions are reversed, such as "study hard to earn money", but in fact, "earn money" is the condition; The definition is not clear, as if two people are debating (in life it is generally not called "debate", it is called "quarrelling". After arguing for a long time, I didn't find that what the two people said was related to the original proposition; Some of the premises are omittedSyllogism, the result is correct, but the premise is wrong; Can recognize other people's sophistry.

in formal logic.

, the fallacy.

It's one of a kind"I want to get away with it"methods of rebuttal and reasoning. On the surface, it seems to agree with the other party's point of view, but in fact it is reasoning according to the other party's point of view, so as to deduce a ridiculous result to prove the falsity of the other party's point of view. Reductive is a method of refutation that is often used by people.

This approach is the method of "retreating and introducing absurdity". The so-called "retreat is advance" is because this method achieves the purpose of refuting the opponent's argument by assuming that the opponent's argument is true; The so-called "introduction of absurdity" is because this method logically leads to absurd conclusions from the arguments of the other side.

As soon as you listen to it, you will immediately feel that the other party's argument is untenable. Then the negation of the posterior inference according to the sufficiency condition hypothesis. Proving the other side's argument is necessarily false.

This step is often not spoken. Because it goes without saying. It is necessary to clarify the law of fallacy and the law of counterproof.

The connection and difference between them.

The connection between them is that the method of reduction is to be used in the law of counterproof. The difference between them is:

The method of counterargument is the method of argumentation, and the method of fallacy is the method of refutation; The fallacy method uses a single form of reasoning, while the law of counterproof is more complex than the fallacy method, and it needs to further apply the law of exclusion after the fallacy method is applied.

Classic examples of fallacies:

NewtonIt was once said: ".Counter-evidence.

He is one of the most skilled mathematicians." Generally speaking, the method of refutation is often used to prove that the positive proof is difficult, the situation is numerous or complex, and the negation of the proposition.

For more obvious questions, the problem may be solved very simply.

The argument of the method of counter-evidence can be briefly summarized as "negation leads to contradictory negation." That is, starting from the negation of the conclusion, drawing contradictions, and reaching a new negation, it can be considered that the basic idea of the law of counter-evidence is the dialectical "negation of negation."

The application of the counter-proof method is to prove that "if p, then q" is a true proposition, starting from the opposite conclusion, and deriving contradictions with facts, theorems, known conditions, basic facts, etc., so that the original proposition is a true proposition.

The process of argumentation of the counter-evidence method is as follows:

First, the thesis is proposed: then the counter-thesis is set and deduced according to the rules of reasoning to prove the falsity of the counter-thesis. Finally, according to the law of exclusion, since the counter-argument is false, the original thesis is true. In the conduct of counter-argument, only the judgment that contradicts the thesis can be used as a counter-thesis, and the opposing judgment of the thesis cannot be used as a counter-thesis, because two judgments with an opposing relationship can be false at the same time.

An important part of the counter-argument is to determine the falsity of the counter-thesis, and it is often necessary to use the fallacy method. Counter-evidence is an effective method of interpretation, especially when it is difficult to make a direct argument or refutation.

The method of counterproof is often used in mathematics. When the argument is not easy or cannot be proved from the front, it is necessary to use the method of counter-proof, which is called so-called"Positive and difficult is the opposite"。

Negative of Conclusion B'In more than one case, it is necessary to put b'The evidence of the various possible situations is denied one by one. Example: At a banquet, there are two kinds of people A, B, and C, one who only tells the truth, and the other who lies, and A says that B and C are lying. B vehemently denied it, but C said that B did lie.

Proofreading. One of A, B, and C tells the truth, and the other lies. If the conclusion is not true, there are five possible scenarios.

A, B, and C all tell the truth;

A and B both tell the truth, and c lies;

a, c, both tell the truth, and b, lie;

B and C both tell the truth, A lies, and A, B, and C all lie. If it is, then A tells the truth, and thus B, C lies, which contradicts itself, and if so, then A tells the truth, and thus blies, which contradicts itself; If it is, then it is contradictory to atell the truth, and thus to clie; If it is, then it is contradictory to clie and thus to blie, and if it is, then it is clying, and thus bto tell the truth, which is contradictory to itself. Therefore, one of A, B, and C tells the truth, and the other lies.

The extended exhaustive fallacy is one of the methods of counter-proof, which first assumes that the conclusion to be proved is not true, and then carries out a series of logical reasoning under this assumption until a contradictory conclusion is reached, and accordingly overturns the original assumption, so as to confirm the validity of the conclusion to be proved. It can also contradict known axioms, theorems, or definitions in mathematics; It can also contradict accepted facts in everyday life; It is even possible to reason from two different perspectives and come to conflicting conclusions.

If he is not a hero if he fails, then Jing Ke is no longer a hero, and his two major goals of sacrificing himself to Qin - assassinating Ying Zheng and forcing Qin to return to Yandi ended in failure. Napoleon was not a hero either, he was defeated at Waterloo and released to St. Helena, where he eventually died of illness and loneliness. Mr. Sun Yat-sen is not even a hero, the achievements of the Xinhai Revolution were stolen by Yuan Shikai, the second revolution failed, the national defense movement still failed, and his will also said that "the revolution has not succeeded" Are they really not heroes?

If the older you get, the more you know, then those centenarians are the most learned people in the world.

If a girl shaves her hair short and breaks up, then a bald person is going to say goodbye to humanity forever!