Robert Goodin has usefully distinguished two models of liberal multiculturalism: “Protective multiculturalism,” which justifies multiculturalist policies, such as granting minority cultures group rights, on the grounds that such policies may be necessary to defend those cultures against oppression, and “Polyglot multiculturalism,” which positively values multiculturalism for sake of its benefits to society at large. Typically, it is the autonomy of a society’s members that multiculturalism is thought to benefit. The purpose of this paper is to call attention to several other possible benefits of multiculturalism. We find in Mill’s discussion of “individuality” three suggestions as to how the social diversity brought by multiculturalism may promote well-being: through self-development, through individuals’ identification of suitable pursuits, and through social progress. While I believe that all three of Mill’s suggestions are worthy of reexamination, inthis paper I focus my attention on defending the latter.