This paper combines the ancient idea that causes necessitate their effects with Angelika Kratzer’s semantics of modality. On the resulting view, causal claims quantify over restricted domains of possible worlds determined by two contextually determined parameters. I argue that this view can explain a number of otherwise puzzling features of the way we use and evaluate causal language, including the difference between causing an effect and being a cause of it, the sensitivity of causal judgements to normative facts, and the (...) semantics of causal disagreements. (shrink)