Some feminists have seen sex role theory as limited, even dangerous; others see it as useful mid-range theory. This article sheds light on this debate through an examination of the discourse of the men's liberation movement of the 1970s. Men's liberation leaders grappled with the paradox of simultaneously acknowledging men's institutional privileges and the costs of masculinity to men. The language of sex roles was the currency through which they negotiated this paradox. By the late 1970s, men's liberation had disappeared. (...) The conservative and moderate wings of men's liberation became an anti-feminist men's rights movement, facilitated by the language of sex roles. The progressive wing of men's liberation abandoned sex role language and formed a profeminist movement premised on a language of gender relations and power. The article ends with a discussion of the implications of this case for debates about sex role theory, and urges the study of contemporary organizations whose discourse is based on the language of sex roles. (shrink)