A particular self-referential paradox relating to the number of words in a descriptive phrase.

Hempel's paradox

The paradox where, given the observation that certain English phrases unambiguously define real numbers while others do not, there is an infinitely long list of English phrases that unambiguously define real numbers, yet (using a similar technique to Cantor's diagonal argument) it is possible to generate another such phrase not in the list.

A paradox arising from the question of what constitutes evidence for a statement. Observing objects that are neither black nor ravens may formally increase the likelihood that all ravens are black, even though, intuitively, these observations are unrelated.

A paradox of self-reference, where, supposing that every man either shaves himself or is shaved by the barber, and the barber shaves all and only the men who do not shave themselves, then it is impossible to determine who shaves the barber.

plural of liar paradox

Grelling-Nelson paradox

(philosophy, logic) A paradox involving statements such as "this sentence is false", or "the following statement is true: the previous statement is false", which cannot be meaningfully regarded as either true or false.

A thought experiment involving a game between two players, one of whom purports to be able to predict the future. The first player has to try to maximize winnings by choosing one of two boxes of money; however, the amount won also depends on whether a prediction made about the choice by the other player proves to be true.

Alternative form of twin paradox