This is from Christopher Kaczor’s book The Ethics of Abortion (2nd ed.), pp 185-187.
8.10 The Right to Control Your Own Body
When defenders of the violinist argument speak of the “right to decide what happens in and to one’s body,” what exactly does the term “right” mean? John Finnis disambiguates the term “right” and utilizes the work of Wesley Hohfeld (Finnis 1973). A Hohfeldian “liberty right” to X is the claim that the agent has no duty not to X. For example, if a person has a right to free speech, this means that the person has no legal or ethical duty to refrain from speaking. By contrast, if a person has a “claim right,” then other people have a duty to aid, provide, or do something or refrain from doing something with respect to the person with that right. An agent’s right to live is a claim right which means that other people have the duty not to intentionally kill the agent.
How do these various kinds of rights apply to abortion? Let’s first look at abortion understood as a claim right. All people have duties not to interfere with other people’s bodies. This duty readily connects to the violinist analogy, for doctors have duties not to hook up unconsenting people to violinists. Patrick Hopkins asserts that “the fetus has no right to occupy its mother’s (or anyone else’s) body” (Hopkins 2008, p. 317). So, does the fetal person violate the claim rights of women to control their bodies?
People do indeed have duties not to make use of the body of other persons. But a human fetus, like a human newborn or a human adult with serious mental handicap, does not have any duties because he or she cannot have a duty to do what is impossible for him or her to do. Abortion cannot therefore be justified in terms of a mother’s claim right against her unborn child.
On the one hand, the “right to control one’s body” could itself be understood as a liberty right. A right to control what happens in and to one’s body may be understood to mean (analytically) that the agent has no duty not to have an abortion. But if the right to control one’s body is understood in this sense, then the assertion of this right to justify abortion is question begging, since precisely what is at issue is whether or not there is a duty to refrain from abortion. If one asks why abortion is permissible, the question remains unanswered if we assert a “right to control one’s body” understood in this sense.
Perhaps the “right to control one’s body” should be understood as a premise in an argument to justify the conclusion that abortion is permissible. However, the right to control what happens in and to one’s body admits of many exceptions both legally and morally. This right does not include the right to take heroin for fun, the right to undress in public, or the right to shout “Fire!” in a crowded theatre, or the right to walk around naked in public. We must use our bodies to pay taxes, sign up for selective service (for men), and so forth. So, taken as a universally true premise, there simply is no such thing as the absolute right to control what happens in and to one’s body. This premise, since it is false, cannot be used to justify abortion.
Indeed, the right to control one’s body ends when the body of another person begins. In the case of pregnancy, there are at least two bodies involved— two beating hearts of circulating blood of different types. Indeed, if the human being in utero is construed simply as a part of the body of the woman absurdities arise. Pregnant women would have four eyes and four legs, and about half the time such a pregnant woman would have a penis. Two human bodies are present in pregnancy, which explains cases of mothers dying in pregnancy but their unborn children surviving, something which is not true of mere parts of human bodies.
A third problem with justifying abortion via a liberty right to control one’s body is the rights of the fetal person. All human persons have claim rights not to be intentionally killed. But if the human fetus is a person, he or she also has a claim right not to be killed. If we grant the supposition of the violinist argument, a liberty right to intentionally kill the human fetus cannot exist, since the claim right of the unborn child not to be killed means that all other people have a duty not to intentionally kill the fetal person. So, the claim right to life of the fetal person means that there is no liberty right to abortion, where abortion means intentionally killing the human being prior to birth as a means or as an end.
In response, Thomson’s argument could be understood as defending that abortion ought not to be understood as intentional killing but rather as removing the developing person with the side-effect of fetal demise. Thomson is defending not termination abortions but only evacuation abortions with the foreseen but not intended death of the unborn.
Thomson may indeed be defending only the foreseen death of the unborn. If so, she has provided no defense of the reality of abortion as practiced. Abortionists have the intention of ending the life of the human being from in utero. For this reason, when the baby survives the abortion, it is accounted by the abortionist as well as others as a “botched” or “attempted” abortion, a failure in what was intended. Indeed, sometimes when the baby is born alive, abortionists will finish the job they set out to do in procuring the abortion, namely a dead child. For example, the Associated Press reported “A doctor [Kermit Gosnell] whose abortion clinic was described as a filthy, foul-smelling ‘house of horrors’ that was overlooked by regulators for years was charged Wednesday with murder, accused of delivering seven babies alive and then using scissors to kill them” (Walters & Dale 2011). Later in pregnancy, following viability, where there is indeed a choice between removing the baby alive or dead, abortionists attempt to secure death.
Epistle of Dude 