Full Idea
What binds the constituents of a structured proposition together into a single unity, a proposition? Can the very same constituents constitute two distinct propositions? These are questions about 'the unity of the proposition'.
Gist of Idea
Unity of the proposition questions: what unites them? can the same constituents make different ones?
Source
Trenton Merricks (Propositions [2015], 4.II)
Book Reference
Merricks,Trenton: 'Propositions' [OUP 2015], p.126
A Reaction
Merricks solves it by saying propositions have no structure. The problem is connected to the nature of predication (instantiation, partaking). You can't just list objects and their properties. Objects are united, and thus propositions are too.