 David Lewis famously tried to analyze causation in terms of counterfactuals (Lewis 1973). He recognized that in order for his theory to succeed, he needed to restrict the analysis to counterfactual relations among distinct events (see especially Lewis 1986). For instance, we typed the word “Lewis” near the beginning of this paragraph. If we had not typed the letters L-e-w, then we would not have typed the word “Lewis”. But typing the letters L-e-w did not cause us to type “Lewis”. Typing L-e-w was part of the act of typing “Lewis”. The events typing L-e-w and typing “Lewis” are not distinct from one another in the right kind of way to stand in causal relations to each other. Lewis’s account of distinctness is somewhat involved, but it specifically excludes relations of logical entailment and spatiotemporal inclusion.