Of all the doctrines of Tlon, none has caused more uproar than materialism. Some thinkers have formulated this philosophy (generally with less clarity than zeal) as though putting forth a paradox. In order to make this inconceivable thesis more easily understood, an eleventh-century heresiarch conceived the sophism of the nine copper coins, a paradox as scandalously famous on Tlon as the Eleatic aporiae to ourselves. There are many versions of that “specious argument,” with varying numbers of coins and discoveries; the following is the most common:

On Tuesday, X is walking along a deserted road and loses nine copper coins. On Thursday, Y finds four coins in the road, their luster somewhat dimmed by Wednesday’s rain. On Friday, Z discovers three coins in the road. Friday morning X finds two coins on the veranda of his house.

From this story the heresiarch wished to deduce the reality—i.e., the continuity in time—of those nine recovered coins. “It is absurd,” he said, “to imagine that four of the coins did not exist from Tuesday to Thursday, three from Tuesday to Friday afternoon, two from Tuesday to Friday morning. It is logical to think that they in fact did exist—albeit in some secret way that we are forbidden to understand—at every moment of those three periods of time.”
The language of Tlon resisted formulating this paradox; most people did not understand it. The “common sense” school at first simply denied the anecdote’s veracity. They claimed it was a verbal fallacy based on the reckless employment of two neologisms, words unauthorized by standard usage and foreign to all rigorous thought: the two verbs “find” and “lose,” which, since they presuppose the identity of the nine first coins and the nine latter ones, entail a petitio principii. These critics reminded their listeners that all nouns (man, coin, Thursday, Wednesday, rain) have only metaphoric value.

-Tlon, Uqbar, Orbis Tertius, Jorge Luis Borges (1941).