What does it mean to be a woman? Do women have a unique nature and a unique vocation? Should feminists work to help women specifically or to support all people? Thinking Woman examines the lives and ideas of women in the history of philosophy who wished to understand and advocate for themselves as women. Some, like Hildegard of Bingen and Edith Stein, found women to be a unique creature designed by God, necessary for good stewardship of creation. Others, such as Mary Wollstonecraft and Sojourner Truth, found women to be identical to men in all but biology and thus identical before the law. Still others, from Simone de Beauvoir to Judith Butler, found the very question troubling as they tried to sort out cultural ideas from biological rules. These women and their views form a canon on the question of women, a canon that can help guide the conversation for thinkers and activists today who want both to understand women and to advocate for justice for all people.