We need to resist the temptation to present noncanonical voices as representative, as introducing diversity by giving the Black or women’s or whatever perspective. Such voices need to be diverse and to disagree among themselves. One of the sillier arguments against taking diversity as a reason for affirmative action has it that doing so presupposes that there is a distinctive perspective a member of the group in question will bring. The reality, of course, is exactly the reverse: it is when members of marginalized groups are scarce that those who are present are put in the role of representatives of their race, gender, disability, sexual identity, or whatever. One of the goals of affirmative action is to have enough members of such groups around that the diversity among them is always apparent (meaning both that there are enough people for the diversity to be represented and that they are sufficiently at home not to need to hide their diversity behind a united front).
Naomi Scheman, Engendering the Subject, 1993