1. To be satisfied means to fulfill a desire. But if all you desire is to be satisfied, you'll never be satisfied.
    Your classic catch-22
  2. If a barber shaves all and only men who do not shave themselves, does he shave himself?
  3. If this sentence is true, Santa Claus exists.
  4. Can an all-powerful God create a rock so heavy He couldn't lift it Himself?