Lorde identified issues of race, class, age and ageism, sex and sexuality and, later in her life, chronic illness and disability; the latter becoming more prominent in her later years as she lived with cancer. She wrote of all of these factors as fundamental to her experience of being a woman. She argued that, although differences in gender have received all the focus, it is essential that these other differences are also recognized and addressed. "Lorde," writes the critic Carmen Birkle, "puts her emphasis on the authenticity of experience. She wants her difference acknowledged but not judged; she does not want to be subsumed into the one general category of 'woman.'" This theory is today known as intersectionality.