The paper proposes a unification of the two main frameworks commonly used for the analysis of collective decisionmaking: the framework of preference aggregation, developed from the seminal work of K. Arrow on social choice theory; and the more recent framework of judgment aggregation. Such unification provides several original insights on collective decision-making problems. The methods used are based on logic and, in particular, on formal semantics. Categories and Subject Descriptors I.2.11 [Artificial Intelligence]: Distributed Artificial Intelligence—Multiagent Systems General Terms Economics, Theory Keywords Collective decision-making, social-choice theory, preference aggregation, judgment aggregation, many-valued logic