This thesis presents an account of the nature of structured propositions and addresses a series of questions that arise from that proposal. Chapter 1 presents the account and explains how it meets standard objections to such views. Chapter 2 responds to the objection that this version of propositionalism is really a form of sententialism by arguing for the distinct advantages of the propositionalist view. Chapter 3 argues against a closely related view of propositions by way of general principles about how to construct such theories. Chapter 4 illustrates how a theory of propositions of the sort proposed can be defended against a recent argument that propositions need not play a central role in linguistic theory.