Abstract

Lewis argued that although paradoxes such as the famous Grandfather Paradox can be solved, only a limited set of time travel fiction is consistent. In this paper, I discuss how to extend a Lewisian approach to a class of time travel fiction not considered by Lewis: transmigration or mental time travel fiction. To this end, Lewis’s definition of personal time needs refining, and this is the primary focus of my paper. I discuss some alternative refinements of Lewis’s definition: a Solely Mental definition and a Causal definition. I end by also applying these definitions to cases of reverse aging.