Chapter 67 <A dog can be a sheep>

During the Warring States period, the debaters of Hui Shi's school put forward many sophistical propositions that violated both common sense and logic. Dogs can be sheep.is one of them. How can a dog be a sheep?These debaters left little material for their specific arguments.Historians of logic speculate that their argument is likely to be as follows, based on Hui Shi’s school’s idea of ​​contract difference: Sheep are animals, and dogs are animals; therefore, dogs are sheep. If this conjecture is correct, the above argument applies a syllogistic reasoning, but it violates the rule that the middle term of the syllogism must be distributed in the premise at least once, and makes a mistake that the middle term is not distributed even once.Because the middle term animal, as the predicate of the two affirmative premises, is not distributed, that is, the major premise does not affirm that sheep is all animals, and the minor premise does not affirm that dogs are all animals.In this way, the middle-breast animal has lost the role of a bridge connecting the big-breast sheep and the small-breast dog, so the conclusion that the dog is a sheep cannot be deduced.

From the perspective of dialectical logic, the above argument made the mistake of substituting the general for the individual.Because animals are general, sheep and dogs are individual, and sheep and dogs not only share the attributes of animals, but also have different characteristics.The above argument only emphasizes the commonality between sheep and dogs one-sidedly, and obliterates the distinctive personalities between the two, thus leading to the sophistical conclusion that dogs are sheep. Sophists often make this mistake in their arguments.For example: (1) Lu Xun exposed the sophistry of the reactionaries in his article "The Soul of Debate": A has a sore, and you have a sore; so you are the same as A.Traitors tell lies, and so do you; so you are a traitor.

(2) During the Cultural Revolution, the Gang of Four slandered learning foreign advanced science and technology as the philosophy of foreign slaves.In their critical articles, there is a popular reasoning: foreign slaves advocate learning foreign advanced science and technology, and you advocate learning foreign advanced science and technology; so you are foreign slaves. The middle terms of the two syllogisms in example (1) are sore and false respectively, and the middle terms of the syllogisms in example (2) advocate learning foreign advanced science and technology, and they are inextensible as predicates of affirmative judgments .Therefore, they all committed the sophistry error that the middle item was not distributed even once.