Brendan Balcerak Jackson (Cologne) gives a talk at the MCMP Colloquium (25 October, 2012) titled "Defusing Easy Arguments for Numbers". Abstract: Pairs of sentences like the following pose a problem for ontology:

(1) Jupiter has four moons.

(2) The number of moons of Jupiter is four.

(2) is intuitively a trivial paraphrase of (1). And yet while (1) seems ontologically innocent, (2) appears to imply the existence of numbers. Thomas Hofweber proposes that we can resolve the puzzle by recognizing that sentence (2) is syntactically derived from, and has the same meaning as, sentence (1). Despite appearances, the expressions ‘the number of moons of Jupiter’ and ‘four’ do not function semantically as singular terms in (2). Hofweber’s primary evidence for this proposal concerns differences in the focus-related communicative functions of (1) and (2). In this paper I raise several serious problems for Hofweber’s proposal, and for his attempt to support it by appeal to focus-related phenomena. I conclude by offering independent evidence for an alternative, purely pragmatic resolution of the ontological puzzle.