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When did philosopher David Kellogg Lewis develop modal realism?
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The American philosopher David Kellogg Lewis developed his theory of modal realism during the 1970s and 1980s.1
Modal realism is the philosophical view that there exists a vast plurality of worlds, each of which is a spatiotemporally and causally closed system, disjoint from all others and containing its own collection of concrete particulars. Lewis argued that these nonactual worlds are just as real as the actual world, with the term "actual" functioning similarly to indexical terms like "here" or "now," depending on the context of the speaker.23