The content of our propositional attitudes is often characterized by assigning them abstract entities, namely propositions. In decision theory the attitudes are also assigned numerical measures. It may thus be asked how assignments of these two types are related to each other-both metaphysically and structurally. In the first section of this paper I argue for the importance of this question and I review Davidson's unified account of decision theory and radical interpretation as a failed attempt to answer it. Then, in the main part of the paper, I present a unified measurement-theoretic account of linguistic meaning, propositional mental content, and action, an account that avoids the difficulties of Davidson's picture. Thus in the second section I outline two theoretical preliminaries (the representational theory of measurement and Savage's decision theory), in the third section I present the proposed novel account, and in the fourth section I defend it against various objections.