Like their predecessors, and like their male counterparts, most women philosophers of the 20th century have significant expertise in several specialities. Moreover, their work represents the gamut of 20th century philosophy's interests in moral pragmatism, logical positivism, philosophy of mathematics, of psychology, and of mind. Their writings include feminist philosophy, classical moral theory reevaluated in light of Kant, Mill, and the 19th century feminist and abolitionist movements, and issues in logic and perception. Included in the fourth volume of the series are discussions of L. Susan Stebbing, Edith Stein, Hedwig Conrad Martius, Simone de Beauvoir, Simone Weil, Mary Whiton Calkins, Gerda Walther, and others. While pre-20th century women philosophers were usually self-educated, those of the 20th century had greater access to academic preparation in philosophy. Yet, for all the advances made by women philosophers over two and a half millennia, the philosophers discussed in this volume were sometimes excluded from full participation in academic life, and sometimes denied full professional academic status.