 Moreover, sex is not the only ground of legally actionable discrimination. Some critical race theorists, queer theorists, disability theorists, and other feminist legal philosophers have both clarified and complicated the issue of equality and difference by pointing to discrimination based on race, class, ethnicity, sexual orientation, disability and age (Mayeri 2011; Nussbaum 2006; Allen 2005; Crenshaw 1996, 1989; Valdes 1995; Matsuda 1987). As discussed above, the scholarship on intersectionality creates complex pictures of identity and the structure of discrimination. For example, employment discrimination against women of color may not be simply a matter of race-plus or sex-plus, but a phenomenon of interaction between these and possibly other categories. Some feminists have pointed out as a problem in particular of liberal feminism that much of its focus is directed to the concerns of white, middle class, professional women (Williams 2011, 1997, 1992; Roberts 2002; Crenshaw et al. 1996). 