70 Paradox Examples That Will Mess With Your Mind

An observation that having many options to choose from, rather than making people happy and ensuring they get what they want, can cause them stress and problematize decision-making.

If you seek pleasure or happiness for the sole purpose of achieving it for yourself, you will fail. Instead, you must pursue other goals that will bring you happiness or pleasure as a side-effect.

The more similar two options are, the more difficult it is to decide between them, and the less consequential the decision becomes. A rational decider might find herself spending the most time on the least important decisions.

Intentionally blank page paradox: Many documents contain pages on which the text "This page is intentionally left blank" is printed, thereby making the page not blank.

Pilots who are psychologically unfit can bail out of combat duty, but anyone who attempts to do so establishes his sanity.

A word that does not describe itself is heterological. Does "heterological" describe itself?

What happens when Pinocchio says "My nose grows now"? Basically, his nose would have to grow to make Pinocchio’s statement not a lie, but then it can’t grow otherwise the statement would not be a lie.

When two countries each have nuclear weapons, the probability of a direct war between them greatly decreases, but the probability of minor or indirect conflicts between them increases.

There should be many alien civilizations in our galaxy if there is nothing particularly special about Earth. We haven't discovered any proof of extraterrestrial intelligent life, though.

Imagine that you are holding a postcard in your hand with the words "The statement on the opposite side of this card is true" inscribed on one side. That will be Statement A. The opposing side of the card states, "The statement on the other side of this card is false," when you flip it over (Statement B). A paradox arises when attempting to assign any truth to either Statement A or B: if A is true, then B must also be true, yet for B to be true, A must be untrue. On the other hand, if A is untrue, then B must also be false, hence A must inevitably be true.

A paradox involves a heap of sand from which grains of sand are removed individually. The dilemma is to think about what happens when the process is done enough times that only one grain remains: is it still a heap? Assuming that removing a single grain does not turn a heap into a non-heap. If not, when did it go from being a heap to not being one?

A law student agrees to pay his teacher after (and only after) winning his first case. The teacher then sues the student (who has not yet won a case) for payment.

Paradox consists of a pair of statements, each of which ‘says’ the other is false.

The idea that people can perform tasks more effectively by focusing less directly on doing them, suggesting that direct intentional effort is not really necessarily the most effective approach to achieve a goal.

If we don’t know what we don’t know, how do we know what to look for? Even if we happen to encounter what we don’t know by chance, we wouldn’t know it and wouldn’t know to inquire.

First noted by Marvin Stern and George Gamow, physicists who had offices on different floors. Gamow, who had an office near the bottom of the building noticed that the first elevator to stop at his floor was most often going down, while Stern, who had an office near the top, noticed that the first elevator to stop at his floor was most often going up. This creates the false impression that elevator cars are more likely to be going in one direction than the other depending on which floor the observer is on.

A younger version of the physicist who is developing a time machine comes visit. The younger version builds the time machine using the schematics that the older version gives him, and uses it to travel back in time as the older version of himself.

If you were to measure the coastline of a country by using a ruler on a globe, you would come out with a vastly different number than if you were to pace around the edge. The closer you look, the more wiggles and squiggliness you come across and instead of converging on a more accurate length, the coastline just keeps getting longer. The smaller your ruler, the longer it gets.

Would a ship still be the same if all of its wooden components were replaced during restoration?

On the one hand, Galileo proposed, there are square numbers. On the other, there are those numbers that are not squares. Put these two groups together, and the total number of square numbers must be less than the total number of square and non-square numbers together. However, because every positive number has to have a corresponding square and every square number has to have a positive number as its square root, there cannot possibly be more of one than the other.