to all women". Much like Crenshaw, Collins argues that cultural patterns of oppression are not only interrelated, but are bound together and influenced by the intersectional systems of society, such as race, gender, class, and ethnicity. Collins describes this as "interlocking social institutions [that] have relied on multiple forms of segregation... to produce unjust results". Collins sought to create frameworks to think about intersectionality, rather than expanding on the theory itself. She identified three main branches of study within intersectionality. One branch deals with the background, ideas, issues, conflicts, and debates within intersectionality. Another branch seeks to apply intersectionality as an analytical strategy to various social institutions in order to examine how they might perpetuate social inequality. The final branch formulates intersectionality as a critical praxis to determine how social justice initiatives can use intersectionality to bring about social change. One writer who focused on intersectionality was Audre Lorde, who was a self-proclaimed "Black, Lesbian, Mother, Warrior, Poet". Even in the title she gave herself, Lorde expressed her multifaceted personhood and demonstrated her intersectional struggles with being a black, gay woman. Lorde commented in her essay The master's tools will never dismantle the master's house, that she was living in "a country where racism, sexism, and homophobia are inseparable". Here, Lorde outlines the importance of intersectionality, while acknowledging that different prejudices are inherently linked. Lorde's formulation of this linkage remains seminal in intersectional feminism. Though intersectionality began with the exploration of the interplay between gender and race, over time other identities and oppressions were added to the theory. For example, in 1981 Cherríe Moraga and Gloria Anzaldúa published the first edition of This Bridge Called My Back. This anthology explored how classifications of sexual orientation and class also mix with those of race and gender to create even more distinct political categories. Many black, Latina, and Asian writers featured in the collection stress how their sexuality interacts with their race and gender to inform their perspectives. Similarly, poor women of color detail how their socio-economic status adds a layer of nuance to their identities, ignored or misunderstood by middle-class white feminists. According to black feminists, experiences of class, gender, and sexuality cannot be adequately understood unless the influence of racialization is carefully considered. This focus on racialization was highlighted many times by scholar and feminist bell hooks, specifically in her 1981 book Ain't I A Woman: Black Women and Feminism.