Linguistic relativity is often defined by its detractors in ways that make it seem a radical and implausible idea. Here, it is taken simply as the claim that linguistic diversity (the different forms of human language) has a nontrivial impact on cognitive diversity (the various ways or styles of thinking in humans). Although I believe that some versions of it are plausible, the aim is not to defend or attack the hypothesis, but to clarify it and to present some philosophical consequences of its acceptance.