Judith Butler is an American philosopher known for her work in feminism, queer theory, and political theory. Some of her major works examine gender and sexuality, challenging essentialist views. In Gender Trouble, she argues that gender is a social construct and performative, rather than determined by sex or biology. She asserts that there is no innate gender identity and that gender is formed through citational acts over time. Butler seeks to deconstruct notions of fixed gender and sexuality, viewing them as cultural rather than natural categories.