What are we to do? Making sense of ‘joint ought’ talk

We argue for three main claims. First, the sentence ‘A and B ought to φ and ψ’ can express what we a call a joint-ought claim: the claim that the plurality A and B ought to φ and ψ respectively. Second, the truth-value of this joint-ought claim can differ from the truth-value of the pair of claims ‘A ought to φ’ and ‘B ought to ψ.’ This is because what A and B jointly ought to do can diverge from what they individually ought to do: it may be true that A and B jointly ought to φ and ψ respectively, yet false that A ought to φ and false that B ought to ψ; and vice-versa. Third, either of two prominent semantic analyses of ‘ought’—Mark Schroeder’s relational semantics, and Angelika Kratzer’s modal semantics—can model joint-ought claims and this difference in truth-value.