Linguistic relativity the thesis that at least some distinctions found in one language are found in no other language (a version of the Sapir-Whorf hypothesis); more generally, the thesis that different languages utilize different representational systems that are at least in some degree informationally incommensurable and hence non-equivalent. The differences arise from the arbitrary features of languages resulting in each language encoding lexically or grammatically some distinctions not found in other languages.
The thesis of linguistic determinism holds that the ways people perceive or think about the world, especially with respect to their classificatory systems, are causally determined or influenced by their linguistic systems or by the structures common to all human languages. Specifically, implicit or explicit linguistic categorization determines or influences aspects of nonlinguistic categorization, memory, perception, or cognition in general. Its strongest form (probably a straw-man position) holds that linguistically unencoded concepts are unthinkable. Weaker forms hold that concepts that are linguistically encoded are more accessible to thought and easier to remember than those that are not. This thesis is independent of that of linguistic relativity. Linguistic determinism plus linguistic relativity as defined here implies the Sapir-Whorf hypothesis.
See also SAPIR-WHORF HYPOTHESI. W.K.W.