What are persons? What is valuable? -- Philosophical considerations -- I was once a fetus: that is why abortion is wrong -- Brain life and the argument from potential: affirming the ontological status of human embryos and fetuses -- Human being, a person of substance: a response to Dean Stretton -- Concept of person in bioethics -- Abortion and virtue ethics -- Embryos, four-dimensionalism, and moral status -- Christian hypothesis -- Fetal interests, fetal persons, and human goods -- Scientific considerations -- Fetal pains and fetal brains -- Biological definition of the human embryo -- Perspectives from law and political philosophy -- Public reason and abortion revisited -- Abortion, sexual markets and the law.