Philosophy 190: David Lewis
Short Writing Assignment 8

Spring, 2014

Instructions

Note: this assignment is for students in Group IV only (see syllabusfor a list of group assignments).


Due, as an attachment, via the “Assignments” tool on ecommons, by midnight Thurs., May 29. eCommons site


Please respond to the following question in two pages or less (double spaced). (Needless to say this should be your own original work.)


Consdier definition M5 of Materialism, the one Lewis settles on as correct:

Among worlds where no natural properties are instatiated, no two differ without differing physically; any two such worlds that are exactly alike physically are duplicates. (“New Work,” p. 37)

Why, according to Lewis, are sparse real universals, or something like them, necessary to make this definition work? In particular: on the following page, Lewis mentions that physical theories “recognize only a limited range of natural properties.” Why not just define a “natural property” as one recognized by (the successful descendant of) our current physical theories?