Logic
- Barbershop paradox: The supposition that if one of two simultaneous assumptions leads to a contradiction, the other assumption is also disproved leads to paradoxical consequences.
- What the Tortoise Said to Achilles "Whatever Logic is good enough to tell me is worth writing down...," also known as Carroll's paradox, not to be confused with the physical paradox of the same name.
- Crocodile dilemma: If a crocodile steals a child and promises its return if the father can correctly guess what the crocodile will do, how should the crocodile respond in the case that the father correctly guesses that the child will not be returned?
- Catch-22 (logic): A situation in which someone is in need of something that can only be had by not being in need of it.
- Drinker paradox: In any pub there is a customer who, if they drink, everybody in the pub drinks.
- Paradox of entailment: Inconsistent premises always make an argument valid.
- Lottery paradox: There is one winning ticket in a large lottery. It is reasonable to believe of a particular lottery ticket that it is not the winning ticket, since the probability that it is the winner is so very small, but it is not reasonable to believe that no lottery ticket will win.
- Raven paradox (or Hempel's Ravens): Observing a green apple increases the likelihood of all ravens being black.
- Unexpected hanging paradox: The day of the hanging will be a surprise, so it cannot happen at all, so it will be a surprise. The surprise examination and Bottle Imp paradox use similar logic
Read more about this topic: List Of Paradoxes
Famous quotes containing the word logic:
“We want in every man a long logic; we cannot pardon the absence of it, but it must not be spoken. Logic is the procession or proportionate unfolding of the intuition; but its virtue is as silent method; the moment it would appear as propositions and have a separate value, it is worthless.”
—Ralph Waldo Emerson (1803–1882)
“Though living is a dreadful thing
And a dreadful thing is it
Life the niggard will not thank,
She will not teach who will not sing,
And what serves, on the final bank,
Our logic and our wit?”
—Philip Larkin (1922–1986)
“...some sort of false logic has crept into our schools, for the people whom I have seen doing housework or cooking know nothing of botany or chemistry, and the people who know botany and chemistry do not cook or sweep. The conclusion seems to be, if one knows chemistry she must not cook or do housework.”
—Ellen Henrietta Swallow Richards (1842–1911)