class to allow his aphorism about Arabic numerals to sink in, then continued. “There is, however, a different way of explaining numbers and this is the method which I prefer. It is that of sets. To my mind it is a more natural interpretation. Numbers are virtual objects; you cannot, for example, own the number two.”
He waited a moment for the ripple of laughter to die down, looking rather pleased with himself. Then he continued: “Sets, as I say, are more fundamental. Zero can be explained as an empty set. In other words, 'You have nothing'. One is a set of one element which contains only an element that is an empty set.