Ethics has seen even more influential work by women and feminist philosophers (naturally, not all feminists are women). For a summary, see Rosemarie Tong, Feminine and Feminist Ethics (Belmont, CA: Wadsworth, 1993). Some of the new work, the so-called "ethics of caring", centered on the work of Nel Noddings, is rapidly becoming a standard chapter in introductory ethics texts.
Much traditional theory in social ethics has been contractualist. The idea is that human relations are based on exchange agreements, whereby each party gives and gets something of equivalent value in return. The "social contract" between the sovereign and the people is an example. So are legal contracts, and, of course, the marriage contract. But women philosophers have pointed out that motherhood, a major and uniquely female experience, hardly fits this model. A mothers day-to-day relationship with a child can hardly be based on a contract with the child, whereby the mother agrees to provide care in exchange for something of equivalent value from the child. Some feminist philosophers such as Sara Ruddick and Virginia Held have proposed that motherhood is a model of virtue superior to the traditional contractualist view. Ruddick and Held are widely anthologized.
Contemporary women philosophers have written extensively on ethical issues that are of particular interest to women, e.g., abortion, the rights of children, pornography, sexism in language, sexuality and sex roles, discrimination in hiring, and the ethics of reproductive technologies such as surrogate motherhood and embryonic gender-selection. Indeed, the most widely-anthologized and influential articles on the ethics of abortion are by the philosophers Judith Jarvis Thomson ("A Defense of Abortion", 1971) and Mary Anne Warren ("On the Moral and Legal Status of Abortion", 1973).
Also, women philosophers such as Karen J. Warren, Val Plumwood, and others have helped formulate a distinctive approach to environmental ethics called eco-feminism. According to Warren, in her essay "The Power and Promise of Ecological Feminism", "ecofeminists insist that the sort of logic of domination used to justify the domination of humans by gender, racial or ethnic, or class status is also used to justify the domination of nature. Because eliminating a logic of domination is part of a feminist critique whether a critique of patriarchy, white supremacist culture, or imperialism ecofeminists insist that naturism is properly viewed as an integral part of any feminist solidarity movement to end sexist oppression and the logic of domination which conceptually grounds it."