What Is an Economic Fallacy?

Fallacy is a Chinese vocabulary, and pinyin is miù lùn. Refers to ridiculous and wrong speech. Also refers to wrongful jail. For example, saying "reading is useless" is purely a fallacy. "Han Shu · Criminal Law": "Husbands have the filial piety and integrity, and they have never had such a criminal fallacy, but they are drowning in the end?"

[miù lùn]

Any word can be deduced from fallacy

The English text of this sentence is "Everything is implied by a fallacy", which is a theorem in logic. (P Q).

The concept of "any sentence can be deduced from a fallacy" was first proposed by Russell. He gave a ridiculous example "If 1 + 1 = 3, then Russell is Pope" and gave "proof":

According to the definition of natural number 3, 3 = 2 + 1, but we know that 1 + 1 = 3, so 1 + 1 = 2 + 1, and use the same axiom to get 1 + 1-1 = 2 + 1-1, that is, 1 = 2;

Consider the set {Russell, Pope}. The number of elements in this set is two, but it has been proved that 1 = 2, so it can also be said that the number of elements in this set is 1. From this, we can conclude that Russell = Pope.

With this example, we can give a formal definition of "logical implication" (ie, "introduction"): "P Q if and only if Q is true or P is false".

Here is a classic paradox: if on a small island, one person says, "Everyone on our island is telling lies." But he is the man on that island.

If this sentence is correct, and what he said is also false, then the people on this island are telling the truth. If the people on the island are telling the truth, that person is also telling the truth, that is, everyone on the island is telling the truth. If so, that person is also telling the truth, then everyone on the island is telling the truth ...

On the contrary, if the words he said were false, that is, the people on the island were telling false stories, he would also be telling lies. If he tells the truth, everyone on the island tells the truth and he tells the truth. If ...

This is a typical example.