The problem of the ‘Unity of the Proposition’ is the problem of explaining the difference between a content-expressing declarative sentence and a ‘mere list’ of referents. The prevailing view is that such a problem is to be solved metaphysically, either by reducing our ontology to exclude propositions or universals, or by explaining how it is possible for a certain kind of complex entity – the ‘proposition’– to ‘unify’ its constituents. I argue that these metaphysical approaches cannot succeed; instead the only viable approach is linguistic, identifying features of the (type–) sentence itself that enable it to express a content. Thus the problem of the ‘Unity of the Proposition’ (distinguishing sentences from lists) is distinct from the problem of ‘propositional unity’ (explaining how the constituents of propositions form a unified content). I suggest that, while the latter problem is not pressing, the former does not permit of an answer which applies in generality in all languages; we can only fully explain the Unity of the Proposition for single languages or groups of similar languages.