 The central concept of feminist epistemology is of situated knowledge: knowledge that reflects the particular perspectives of the knower. Feminist philosophers explore how gender situates knowing subjects. They have articulated three main approaches to this question—feminist standpoint theory, feminist postmodernism, and feminist empiricism—which have converged over time. Conceptions of how gender situates knowers also inform feminist approaches to the central problems of the field: grounding feminist criticisms of science and feminist science, defining the proper roles of social and political values in inquiry, evaluating ideals of objectivity, and reforming practices of epistemic authority and epistemic virtue.