ABSTRACT
When people say that such-and-such a thing “is non-existent” they usually mean that there is not any “thing” of the kind spoken of. Venn meant this when he described 1 his encounter with what he imagined to be a very ingenious tradesman: “I once had some strawberry plants furnished me which the vendor admitted would not bear many berries. But he assured me that this did not matter, since they made up in their size what they lost in their number. (He gave me, in fact, the hyperbolic formula, xy = c, to connect the number and magnitude.) When summer came, no fruit whatever appeared. I saw that it would be no use to complain, because the man would urge that the size of the non-existent berry was infinite, which I could not see my way to disprove. I had forgotten to bar zero values of either variable.”
