 Stressing that fetus are not self conscious subjects of experience, some philosophers have denied that fetuses are moral persons with rights to life that outweigh women’s privacy rights. Those who oppose abortion privacy argue that abortion should not be left to private choice because the unborn are in fact equal members of the moral community, along with newborn infants. Membership in the moral community is conferred by human status or potential personhood, these philosophers argue. Religious ethicists sometimes characterize the unborn as acquiring souls in utero. Some moralists maintain that women’s decisional privacy must yield if science establishes that a totally unique human life comes into being with fertilization of an ovum. In support of moral and legal abortion rights, Peter Singer has argued that science proves that unique human lives do not begin at conception. Instead, fertilization begins a process of initially pluripotent cell development that may result in several human lives, due, e.g., to twinning and other divisions, or in no human life, due, e.g., to defects that result in spontaneous abortion. Philosophers Margaret Little and Rosalind Hursthouse contributed nuance to the ethics of abortion debate by arguing that while autonomy and privacy concerns are important, sui generis considerations of obligation and virtue are ethically relevant to decisions about terminating a pregnancy (Little 1999; Hursthouse 1991).