“But what G. Cantor posits as the defining formal property of an infinite set is that such a set can be put in a 1-1C with at least one of its proper subsets. Which is to say that an infinite set can have the same cardinal number as its proper subset, as in Galileo’s infinite set of all positive integers and that set’s proper subset of all perfect squares, which latter is itself an infinite set.”

— David Foster Wallace