Metaphysical explanations: The case of singleton sets revisited

Many contemporary metaphysicians believe that the existence of a contingent object such as Socrates metaphysically explains the existence of the corresponding set {Socrates}. This paper argues that this belief is mistaken. The argument proposed takes the form of a dilemma. The expression “{Socrates}” is a shorthand either for the expression “the set that contains all and only those objects that are identical to Socrates” or for the expression “the set that contains Socrates and nothing else”. However, Socrates' existence does not explain the existence of the set that contains all and only those objects that are identical to Socrates, because there is such a set no matter whether or not Socrates exists. And although Socrates' existence does explain that of the set that contains Socrates and nothing else, this explanation is a conceptual rather than a metaphysical one. Both these claims rely on a deflationary account of the use of set theoretic vocabulary that is explained, though not properly justified, in the paper.