What is a Paradox

Famous Paradoxes

A paradox is a statement that contradicts itself or a situation which seems to defy logic. That's a simple definition of paradox.

Often premises can be proven false which rectifies the contradiction. Sometimes they are just play on words, however, some paradoxes still don't have universally accepted resolutions.

On this page you can find several good paradox examples to tease your mind.

Paradox Examples

1. Liar Paradox (Epimenides Paradox)

This is a well known paradox written by the great stoical logician Chrysippos. The poet, grammarian and critic Philetus of Cos was said to have died of exhaustion attempting to resolve it.

  1. A Cretan sails to Greece and says to some Greek men who are standing upon the shore: "All Cretans are liars." Did he speak the truth, or did he lie?
  2. A week later, the Cretan sailed to Greece again and said: "All Cretans are liars and all I say is the truth." Although the Greeks on the shore weren't aware of what he had said the first time, they were truly puzzled.

If someone says "I always lie", are they telling the truth? Or are they lying?

2. Double Liar Paradox (Jourdain's paradox)

This version of a famous paradox was presented by English mathematician P. E. B. Jourdain in 1913.
The following is written on opposite sides of a card:

Back side:
THE SENTENCE ON THE OTHER SIDE OF THIS CARD IS TRUE.

Face side:
THE SENTENCE ON THE OTHER SIDE OF THIS CARD IS FALSE.

3. Barber Paradox (Russell's Paradox)

Analogue paradox to the 'liar paradox' formulated by English logician, philosopher and mathematician Bertrand Russell.
In a village, the barber shaves everyone who does not shave himself/herself, but no one else.
Who shaves the barber?

 

4. Lazy-bones Paradox

If destiny designed a master plan which defines everything that is to happen, isn't it useless, for example, to go to a doctor? If I am ill and it is my destiny to regain health, then I will regain health whether I visit a doctor or not. If it is my destiny to not regain my health, then seeing a doctor can't help me.
How could you question the presented opinion?


My Favorite Sophisms

1. Crocodile Sophism

A slim crocodile living in the Nile took a child. His mother begged to have him back. The crocodile could not only talk, but was also a great sophist and stated, "If you guess correctly what I will do with him, I will return him. However, if you don't predict his fate correctly, I'll eat him."
What statement should the mother make to save her child?

2. Is it possible to give what we don't have?

Sophist: "Yes, greedy man gives his cash with sorrow. However, he doesn't have the cash with sorrow, so he gives what he doesn't have."

3. What is better - eternal bliss or a simple bread?

What is better than eternal bliss? Nothing. But a slice of bread is better than nothing. So a slice of bread is better than eternal bliss.

A few sentences from life - funny paradox quotes

  1. Nobody goes to that restaurant; it's too crowded.
  2. Don't go near the water 'til you have learned how to swim.
  3. The man who wrote such a stupid sentence can not write at all.
  4. If you get this message, call me, and if you don't get it, don't call.
  5. ADVERTISEMENT: Are you an analphabet? Write a letter and we will send you free of charge instructions how to undo it.

Think about these

  1. Let's say there is a bullet which can shoot through any barrier. Let's also say there is an absolutely bullet-proof armor which no object can penetrate. What will happen if such a bullet hits such an armor?
  2. Can a man drown in the fountain of eternal life?
  3. Your mission is not to accept the mission. Do you accept?
  4. A girl goes into the past and kills her Grandmother. Since her Grandmother is dead, the girl was never born. If she were never born, she never killed her grandmother.
  5. If the temperature this morning is 0 degrees and the Weather Channel says, "it will be twice as cold tomorrow", what will the temperature be?
  6. Answer truthfully (yes or no) to the following question: Will the next word you say be 'no'?
  7. What happens if you are in a car going the speed of light and you turn the headlights on?
  8. I conclude with this challenge:
    Let the God Almighty create a stone, which he is not capable of lifting!
 

Share this page with your friends

Check out more Logic Puzzles >>