The best paradoxes raise questions about what kinds of contradictions can occur--what species of impossibilities are possible. Argentine writer Jorge Luis Borges (1899-1986) whose work appeals to all lovers of paradox, explored many such questions in his short stories. In "Tlon, Uqbar, Orbis Tertius," he describes an encyclopedia, supposedly from another world, created as an elaborate hoax by a group of scholars. Borges's scholars even imagine the paradoxes of their fictitious world; so alien is the thinking of "Tlon" that their paradoxes are commonplace to us. The greatest paradox of Tlon is that of the "nine copper coins":

--> quote

On Tuesday, X crosses a deserted road and loses nine copper coins. On Thursday, Y finds in the road four coins, somewhat rusted by Wednesday's rain. On Friday, Z discovers three coins in the road. On Friday morning, X finds two coins in the corridor of his house. ... The language of Tlon resists the formulation of this paradox; most people did not even understand it. The defenders of common sense at first did no more than negate the veracity of the anecdote. They repeated that it was a verbal fallacy, based on the rash application of two neologisms not authorized by usage and alien to all rigorous thought: the verbs "find" and "lose," which beg the question, because they presuppose the identity of the first and of the last of the nine coins. They recalled that all nouns (man, coin, Thursday, Wednesday, rain) have only a metaphorical value. They denounced the treacherous circumstance "somewhat rusted by Wednesday's rain," which presupposes what is trying to be demonstrated: the persistence of the four coins from Tuesday to Thursday. They explained that "equality" is one thing and "identity" another, and formulated a kind of reductio ad absurdum: the hypothetical case of nine [people] who on successive nights suffer a severe pain. Would it not be ridiculous--they questioned--to pretend that this pain is one and the same? ... Unbelievably, these refutations were not definitive...

<-- end quote

To the Tlon way of thinking, the "nine copper coins" has the quality of true paradoxes, that it is never fully explained away. It is interesting to wonder if our paradoxes would seem as banal to the inhabitants of another world.