David K. Lewis

David K. Lewis was an influential American philosopher known for his work in various areas, including metaphysics, philosophy of language, and philosophy of mind. He is best known for his theory of modal realism, which suggests that possible worlds are as real as the actual world we live in. This means that all possible scenarios and outcomes exist in their own separate worlds. Lewis also made significant contributions to discussions on counterfactuals, the nature of meaning, and the foundations of social and ethical theory. His ideas have profoundly shaped contemporary philosophical thought.