Apologies for the short one today- I usually write these in a burst of motivation, and I haven’t really had one of those this week.
The Liar’s Paradox is the simplest paradox there is. It’s just one sentence long, and it’s a total mindblow.
Here it is.
“This sentence is a lie.”
Well, is it? Because if you say that it is a lie, then the statement must be true, since that’s what it claims. And if you say that the sentence is true, then it must be a lie, because it says that it is a lie. Either way, you find yourself saying that the sentence is true and false at the same time- which is impossible! Paradox!
The cool thing about the Liar’s Paradox is that it can be remixed and twisted into tons of other paradoxes.
For example, there’s the Card Paradox, where the front of a card says “The back of this card is true,” and the back of the card says “The front of this card is a lie”.
Or there’s the Cretan Paradox, where someone from Crete says “all Cretans are liars” or “Cretans never tell the truth”.
Or there’s the Pinocchio Paradox, where no one can decide what happens if Pinocchio says “My nose will grow now”.
Or, of course, there is heterological, which I covered in an earlier post because I love how small it is.
All of these paradoxes are slow-acting, by which I mean, they don’t seem paradoxical immediately, but if you stare at them for a moment and think it through, it hits you. For that reason, when I need to tell someone a quick, easy-to-get paradox, I go for a version of the Liar’s paradox.