In this thesis, the author considers the nature of the relativity thesis of language and some of the philosophical problems that arise from it. The thesis has probably become best known as the Sapir-Whorf hypothesis of the relativity of language, after two scholars of American Indian languages who supported various forms of the hypothesis. Views similar to theirs have been expressed by a number of different authors both before and after the writings of Sapir and Whorf. The introduction is devoted to a discussion of some of the variety of the formulations of the thesis. There is mention of a few of the many authors who have been thought to be "relativists". Some attempt has been made by others to systematise the various possible theses, and ...