This chapter discusses typologies of modern feminist theories. Lorber's categorisation of feminist theories distinguishes between three broad kinds of feminist discourses: gender reform feminisms, gender resistant feminisms, and gender revolution feminisms. Lengermann and Niebrugge-Brantley categorise the various types of feminist theories as theories of gender difference, theories of gender inequality, theories of gender oppression, and theories of structural oppression. All theories of gender difference are based on the thesis that the differences between men and women are immutable. These theories include cultural feminist theories, institutional role feminist theories, and existential feminist theories. Cultural feminism is a variety of feminism emphasising essential differences between men and women, based on biological differences in reproductive capacity. Institutional role feminist theories argue that gender differences result from the different roles that women and men come to play within various institutional settings. Existential feminist theories focus on the marginalisation of women as other in a male-created culture.