It is commonly taken for granted that abortion is necessarily impermissible if the fetus is a person with a right to life. In her influential essay “A Defense of Abortion,” Judith Jarvis Thomson offers what I will call the violinist example to show that merely having a right to life does not in and of itself give rise in the fetus to a right to use the mother's body. On Thomson's view, if the fetus has a right to use the mother's body that precludes terminating its life by means of an abortion, it is because the mother did something to give the fetus that right. Thus she concludes that the proposition that the fetus is a person does not imply that abortion is morally impermissible.