What is the theme in Sister Outsider: Essays and Speeches by Audre Lorde?

Institutional dehumanization is the central theme in this book. All of the essays and speeches in Sister Outsider deal in one way or another with the problems of institutional dehumanization in the society of the late 1970s and early 1980s in America. Institutional dehumanization is a pattern in a given society of devaluing the individuality of its members in favor of other ideals. American society, to Lorde, values profit over human interests, and this is exacerbates the problems created by racism, sexism, and other prejudices. Groups that are marginalized by prejudice are further marginalized because they have little economic power. White, heterosexual, patriarchal society discourages the expression of traits that do not fall into its norms.