Title: The Genesis of Lewis’s Counterfactual Analysis of Causation

Abstract: Lewis presented a prototype counterfactual analysis of causation back in 1958 — aged just 16 or 17 — in the very first undergraduate philosophy essay he ever wrote. I place this paper in its historical context, relating it to the state of the debate at that time both about counterfactuals and, in philosophy and law, about causation. I also trace his view as it developed in two further versions of the paper written during the following two years, and say something about the further development of his view between then and the publication of his seminal ‘Causation’ in 1973.