Full Idea
Consideration of our ability to count objects across possibilities strongly favour both the Barcan formula and its converse.
Gist of Idea
Our ability to count objects across possibilities favours the Barcan formulas
Source
Timothy Williamson (Truthmakers and Converse Barcan Formula [1999], §3)
Book Reference
-: 'Dialectica' [-], p.267
A Reaction
I'm not sure that I can understand counting objects across possibilities. The objects themselves are possibilia, and possibilia seem to include unknowns. The unexpected is highly possible.