Thomson characterizes the prolife argument in this way: “Every person has a right to life. So the fetus has a right to life. No doubt the mother has a right to decide what shall happen in and to her body; everyone would grant that. But surely a person’s right to life is stronger and more stringent than the mother’s right to decide what happens in and to her body, and so outweighs it. So the fetus may not be killed; an abortion may not be performed.” Thomson then introduces us to her famous violinist analogy. In it you are asked to imagine that you have been kidnapped and rendered unconscious by a vigilante gang of classical music aficionados who have surgically connected you to an unconscious violinist for whom you are alone anatomically suited to be his organic dialysis machine until he fully recovers nine months later. You awake and are told that the violinist will die if you unplug yourself from him. Thomson argues that even though the violinist has a right life, you nevertheless have a right to unplug yourself from him. This allows her to make the point that even if a person, X, has a right to life, that right by itself does not entitle X to coerce another person, Y, to provide bodily aid and sustenance to X, even if such assistance is necessary to keep X alive.
You can read Thomson's article here. In addition to chapter 7 in my book Defending Life: A Moral and Legal Case Against Abortion Choice (Cambridge University Press, 2007), the following are publications of mine that offer critiques of Thomson's argument as well as similar ones:
- Francis J. Beckwith, "Defending Abortion Philosophically: A Review of David Boonin's A Defense of Abortion."Journal of Medicine & Philosophy 31 (April 2006): 177-203.
- Francis J. Beckwith and Steven D. Thomas, "Consent, Sex, and the Prenatal Rapist: A Brief Reply to McDonagh"s Suggested Revision of Roe v. Wade." Journal of Libertarian Studies 17.3 (Summer 2003): 1-16
- Francis J. Beckwith, “Personal Bodily Rights, Abortion, and Unplugging the Violinist.” International Philosophical Quarterly 32.1 (March 1992): 105-118.