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What are the famous paradoxes?
1, a white horse is not a horse

Speaking of paradox, China's famous paradox: A white horse is not a horse. Gong Sunlong thinks that a white horse is not a horse, because "horse" emphasizes a kind of life, while "white horse" emphasizes a kind of color, and their definitions are different.

Someone asked Gong Sunlong: If there is a white horse now, it can't be said that there is no horse. Since a white horse means a horse, why is it said that a white horse is not a horse?

Gong Sunlong said: If you want to find a horse, you can bring a Huang Ma or a dark horse. If you want a white horse, neither Huang Ma nor a dark horse will do. If a white horse is a horse, then finding a white horse is finding a horse. If I say I want a white horse, but you bring a Huang Ma or a dark horse, it is obviously wrong. Therefore, a white horse is not a horse.

Someone asked: All horses in the world have their own colors. If you say so, are there no horses in the world? Gong Sunlong added: Horses have colors, so they have white horses. If a horse has no color except itself, how can it be said to be a white horse? Therefore, when it comes to white, it is not a horse. The requirement of a white horse is that it must be as white as a horse, so it is not a horse.

There are still many issues to be discussed between the two sides, so I won't go into details because of the limited space. I believe everyone also realized the main idea of GongSunLong from this paragraph. Today, there are still many people who think about this problem from the perspective of logic and even mathematics.

2. The paradox of hanging

In the famous novel Don Quixote, the author described a very strange country. This country has a very wonderful rule. They ask travelers who come here to explain what they are doing here. If they are wrong, they will be hanged. No matter what the traveler says, he may be banned by this country, which will lead to his failure and eventually end in hanging.

However, there is a traveler who is very clever. When asked this question, he thought for a moment and said, I'm here to hang myself. When this sentence was said, even the soldiers were dumbfounded. If this man is right, then according to the regulations, they can't hang him; However, if he is wrong, then he has not been hanged here, so there is no reason to hang him. In this way, the man saved his life.

3. The barber paradox

In fact, the barber paradox is somewhat similar to the liar paradox. The paradox is that it is strange to have a barber. He made an interesting rule, that is, to cut the hair of local people who don't cut their own hair. This rule is a paradox: does he want to cut his hair?

If he doesn't give himself a haircut, then he is the local people who don't give himself a haircut, and he is the object of his own haircut; If he cuts his own hair, he breaks his own rules, because he doesn't cut his own hair for those who can cut their own hair.

4. Theseus' ship

The ship of Theseus first came from Plutarch, an ancient Greek philosopher in the 1 th century. He put forward a famous thought experiment: suppose there is a big ship that ages with time, and people have to constantly replace its deck, parts and equipment.

At first, I just changed a deck of cards. As time went on, more and more parts were replaced, until one day, even the last original brand was replaced. So, is this ship still the original one?

If this ship in theseus is a new ship, then the question comes: This ship has never disappeared. How can we talk about a new ship? If it's still the original ship, it's meaningless, because everything on the old ship is gone. What makes you say it's still the original ship?

5. Tram problem

Of all the paradoxes, nothing is more controversial than the tram problem, because it involves ethical issues. This paradox assumes that a train (or tram) is running on the track, and suddenly it is found that there is a frenzied person in front who binds five people to the track. At this time, it was too late for the train to brake, and five innocent people were at stake.

At this time, the driver found a fork in the track and could make an emergency turn. Desperately, however, at that fork in the road, there was another person tied to the tracks. So, should he change?

At first glance, turning is a better choice. After all, everyone knows that 5 > 1 can save four more lives. However, isn't the man at the fork in the road the life of a living person? Why is he unlucky? Moreover, if the driver chooses to take the initiative to open it, then he will change from a helpless person to an active murderer. Is this really appropriate?