Philosophy 188 - 10.1.1 The Abortion Debate

This section investigates biological, political, legal, and moral aspects of the issue of abortion. Unlike a miscarriage, a spontaneous loss of pregnancy due to injury or natural defect, an abortion is the intentional ending of a pregnancy. When abortions are medically induced, a pregnancy is terminated using drugs, surgery, or a combination of the two. In some cases, abortions are performed out of medical necessity to save the life of a pregnant person (therapeutic abortion), while in others a person who is pregnant elects to have the procedure for other reasons.

Political efforts to legalize contraception and later abortion arose as part of many women’s rights movements. As shown in Figure 10.2, some countries still prohibit abortion, and others place limits on when it is allowed, such as when the life of the person carrying the pregnancy is at risk.

A map of the world with shading to indicate the legality of abortion. In the following nations/regions abortion is available on request, with various gestational limits: Russia, Turkey, China, Australia, most of Europe, Canada, the United States, Argentina, and South Africa. In the following nations/regions abortion is allowed on broad social/economic grounds: India, Japan, Finland, England, Ethiopia, Democratic Republic of the Congo. In the following nations/regions, abortion is allowed to save or preserve the health of the pregnancy carrier: most of Africa, most of South America, most of the Middle East, Mexico, and Poland. In the following nations/regions, abortion is prohibited entirely: Egypt, Iran, the Philippines, portions of Africa, potions of Central America.
Figure 10.2 Legal status of abortion around the world as of March 2022. (source: Center for Responsive Politics; attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

In the United States, the right to an abortion prior to the viability of the fetus was deemed protected by the Constitution in the historic Supreme Court decision Roe v. Wade (1973). The court established a trimester system to guide abortion decisions. The court initially acknowledged an unmitigated right to abort in the first three months of pregnancy but left it up to the government to regulate abortion in the second trimester and restrict or ban it in the last trimester if the life of the person carrying the pregnancy was not in danger.

A subsequent Supreme Court decision, Planned Parenthood v. Casey (1992), reaffirmed Roe v. Wade and ruled that state abortion regulations could not place serious obstacles in the path of someone who chose to seek an abortion before a fetus was viable. The decision also replaced the trimester system with the notion of fetal viability—or the fetus’s ability to survive outside the womb (approximately at 25 to 28 weeks). Someone therefore cannot freely seek an abortion if the fetus is viable.

Utilitarianism and Liberal Views on Individual Rights

Normative moral theories, such as those we considered in the previous chapter, factor into how societies view abortion. In Hinduism, for example, moral actions are based on the principle of ahimsa, or “non-harming,” which means that in considering abortion, the choice is governed by what does the least harm to all involved (e.g., to the parents, the fetus, and society). Portions of the Vedas, Hinduism’s most sacred texts, condemn abortion (BBC 2009). Hinduism considers abortion wrong unless it is necessary to save the life of the person carrying the pregnancy. At the same time, in practice, abortion is common in India because some families prefer to have boy children (Dhillon 2020).

Utilitarianism, the consequentialist approach first advanced by Jeremy Bentham, judges an action to be moral if it provides the greatest good to the greatest number. John Stuart Mill’s work On Liberty popularized and adapted this idea so that it could be implemented within representative governments. Mill recognized that the natural rights of various individuals in society will often come into conflict. To maximize individual freedom, Mill proposed the harm principle. It states that a person’s actions should only be limited if they harm another person. A person’s speech should therefore not be curtailed unless it harms another by, for example, directly inciting violence. The harm principle became the cornerstone of 19th-century liberalism. As a result, many people living in liberal societies today evaluate the morality of abortion by weighing the rights of the pregnant person against the rights of the living organism inside the womb. Those who support abortion tend to use the term fetus for the living organism and do not regard it as a person with rights. Those who oppose abortion use the term unborn child and maintain that it has the rights of personhood.

Metaphysical perspectives heavily inform the debate over whether or under what circumstances an abortion is a moral act. For some, the question revolves around what constitutes a person and what rights persons and nonpersons possess. For those who embrace the Judeo-Christian view that humans have a mind, body, and soul, the question often becomes about when the soul enters the body.


Central to the abortion debate, the concept of personhood is best understood as a capacity humans possess that distinguishes them as beings capable of morality. Historically, philosophers like Aristotle and Immanuel Kant have identified reason as a principal factor that justifies the special value assigned to humans. Aristotle argued that rational activity is the peculiar function of humans. He thought we perfect ourselves by perfecting our rational nature. Kant located our worth and dignity in our capacity for rationality. He tells us that “rational beings are called persons inasmuch as their nature already marks them out as ends in themselves” (Kant 1997, 4:428). In other words, personhood, for Kant, is contingent on possessing a rational nature.

The question, then, is when personhood begins. No one is a fully functioning rational agent the moment they are born. In fact, we categorize some humans as dependents, as unable to act as rational agents, when their reason is not fully functioning or formed (e.g., children or those with late-stage Alzheimer’s). Is there some threshold or line of demarcation that distinguishes the point at which reason is sufficiently developed for a human being to be considered a person by this definition? What would it mean for a society if only those who met that threshold were guaranteed the right to life?

Aristotle and Potentiality

The opening of the chapter on metaphysics considered the acorn and oak tree, asking how a being (in this case the acorn) can change so radically and yet remain essentially the same thing. Plato suggested that beings in the physical world are imperfect reflections of perfect forms that are part of an invisible, nonmaterial world. Whereas forms represent an unchanging ideal, beings in this world change. Aristotle proposed the theory of hylomorphism, which states that form is actually present in the material world and responsible for causing the acorn to actualize its potential as an oak tree. From this perspective, just as the acorn contains the essential identity of the fully grown oak tree, so does the human embryo contain the essential identity of a human being. Since the embryo contains the human essence, pro-life advocates argue that it is just as immoral to kill an embryo as to kill a human that has been born (Lee 2004).


Aristotle’s concept of hylomorphism is explored in greater depth in the chapter on metaphysics and the chapter on value theory.

Aristotle and the Soul

For Aristotle, the soul is the form of the living body. In his work On the Soul, Aristotle identifies three types of souls. The soul of a plant acts upon the body so that it can survive and reproduce. The soul of a lower-level animal acts on the body so that it can survive, reproduce, perceive, and act. The soul of a human makes it possible for the body to fulfill all the purposes of a lower-level animal and carry out rational thought. Some have argued that Aristotle believed that the rational soul only entered the human body once it was equipped with organs, at 40 days or more after conception. However, this is likely a misinterpretation promoted by the Greek philosopher Alexander of Aphrodisias from 200 CE onward. In his text Generation of Animals, Aristotle conveys the belief, shared by others of his day, that ensoulment occurs upon fertilization (Bos 2012). Yet the belief that the soul enters the body after 40 days—whether or not Aristotle supported it—became widespread within monotheism and has greatly impacted the abortion debate.

Ensoulment in the Jewish, Christian, and Muslim Traditions

Today major monotheistic religions object to or seek to limit abortions because they believe that a fetus has a God-given soul. To abort then is to destroy God’s creation. The Hebrew Bible, which is part of both Jewish and Christian scripture, is silent on this issue of ensoulment. Genesis 2:7 describes how God created the first man, Adam: “then the Lord God formed man from the dust of the ground, and breathed into his nostrils the breath of life; and the man became a living being.” One of the Hebrew words for soul, neshama, also means “breath.” In Judaism, the introduction of form or soul into the body becomes an act of God that gives life. No mention is made in the first five books of Moses, the Pentateuch, about when this occurs in natural procreation. The later Babylonian Talmud, compiled between 200 and 500 CE, divulges that “the embryo is considered to be mere water until the fortieth day” (quoted in Schenker 2008, 271). This pronouncement may reflect the influence of Greek ideas.

The Aristotelian view of ensoulment is expressed within Christianity. The influential Christian theologian Saint Augustine (354–430 CE) saw the killing of a 40-day-old fetus as an act of murder. A century later, the code of the Byzantine Emperor Justinian I, who reigned from 529 to 565 CE, declared that fetuses under 40 days did not possess a soul (Jones 2004). In the 12th century, the philosopher and theologian Thomas Aquinas also followed Aristotle’s thinking and suggested that a human soul was not fully “formed” until a period of time after conception (40 days for boys and 90 days for girls). Moreover, while Aquinas did not sanction abortion at any stage of pregnancy, he specifically notes that murder has been committed only after the fetus has become animated or ensouled. Aquinas’s understanding of ensoulment remained the official church view until late into the 19th century. Pope Pius IX (1792–1878) altered the official position of the church on ensoulment in order to address theological concerns regarding the Immaculate Conception (McGarry 2013). Beginning with Pope Pius IX, then, the church’s view has been that the soul is present at conception.

According to the Hadith, which along with the Quran constitutes the central written texts of Islam, the soul enters the body 120 days after conception. Yet Islamic clerics have restricted abortions to the first 40 days or prohibited them altogether—as the Quran implores parents not to kill their children for fear of want (Albar 2001). Like in Judaism and Christianity, opposition to abortion arises from a belief in the sanctity of life that God has bestowed on his creations.

Read Like a Philosopher

This excerpt from Thomas Aquinas’s Summa Theologica addresses questions of how and why the soul should be viewed as distinct from the body and how we might go about defining the soul.

To seek the nature of the soul, we must premise that the soul is defined as the first principle of life of those things which live: for we call living things “animate,” [*i.e., having a soul] and those things which have no life, “inanimate.” Now life is shown principally by two actions, knowledge and movement. The philosophers of old, not being able to rise above their imagination, supposed that the principle of these actions was something corporeal: for they asserted that only bodies were real things; and that what is not corporeal is nothing: hence they maintained that the soul is something corporeal. This opinion can be proved to be false in many ways; but we shall make use of only one proof, based on universal and certain principles, which shows clearly that the soul is not a body.

It is manifest that not every principle of vital action is a soul, for then the eye would be a soul, as it is a principle of vision; and the same might be applied to the other instruments of the soul: but it is the first principle of life, which we call the soul. Now, though a body may be a principle of life, as the heart is a principle of life in an animal, yet nothing corporeal can be the first principle of life. For it is clear that to be a principle of life, or to be a living thing, does not belong to a body as such; since, if that were the case, every body would be a living thing, or a principle of life. Therefore a body is competent to be a living thing or even a principle of life, as “such” a body. Now that it is actually such a body, it owes to some principle which is called its act. Therefore the soul, which is the first principle of life, is not a body, but the act of a body; thus heat, which is the principle of calefaction, is not a body, but an act of a body.

Secular Notions of Personhood

Some contemporary philosophers have laid aside a belief in a God-given soul and turned to modern views of personhood to justify both support for and opposition to abortion. Mary Anne Warren, for example, identifies five characteristics essential to the concept of personhood (Warren 1973):

  • Consciousness (in particular, the capacity to feel pain)
  • Reasoning (the developed capacity to solve new, complex problems)
  • The presence of self-awareness and self-concepts
  • Self-motivated and self-directed activity
  • The capacity to communicate messages that are not definite or limited in terms of possible content, topic, or type

Warren argues that a fetus is not a person because it does not satisfy any of the characteristics essential to personhood. Abortion, Warren argues, is always morally permissible because a fetus is not a person and does not have rights (e.g., it does not have a right to life). The rights of the person carrying the pregnancy will always override or outweigh any consideration that might be given to a fetus. Warren believes there is no moral basis for limiting or restricting abortion, but she recognizes the possibility that we might do so on nonmoral (practical or medical) grounds. For example, we might justify restricting abortion in a situation where someone would suffer serious harm from medical complications if the procedure were performed.

Others argue that it is not the rational ability present in an individual that makes them a person or secures their moral status, but rather that our rational nature grounds our moral status—and if human nature is the source of our worth, then any human, even a child, has value whether their reason and agency has fully developed. Children, for example, are not fully functioning rational agents. We recognize this distinction, but we do not use it to justify intentionally harming children or using them as a means to our own ends. We assume that children, like all humans, possess a worth and value that prohibits such treatment. Similarly, people who oppose abortion say that the unborn are potential persons, which is sufficient to grant the unborn child at least a right to life.

Some philosophers, like Ronald Dworkin, go a step further, arguing that full moral status is assigned to any human in virtue of being a member of the human species (Dworkin 1993). Dworkin’s approach focuses on whether an entity is human and uses that as a basis for assigning full moral status rather than making such status contingent on whether a specific individual has fully formed rational capacities.

The Right to Bodily Autonomy

When the issue of abortion is couched in terms of rights, the debate centers on the conflict between the right(s) of the fetus or unborn child and the rights of the pregnant person. If a fetus has a right to life, then the question is whether its right is sufficiently strong to outweigh someone’s right to bodily autonomy—the right of individuals to determine what happens to their bodies.

In A Defense of Abortion, for example, Judith Jarvis Thomson (1929–2020) set out to show that granting a fetus a right to life does not mean that its right is unlimited. She proposed the following thought experiment: Imagine that you wake up one morning and find yourself in the hospital lying next to a famous violinist, currently unconscious, with a fatal kidney ailment. The Society of Music Lovers has reviewed all the available medical records and found you to be the only suitable match for the violinist. They kidnapped you and plugged his circulatory system into yours so that your kidneys can filter out the poisons in his bloodstream. This will cure him within nine hours. Do you have an obligation to stay plugged in? What if the time needed to cure him is nine days? Nine months? Nine years? At what point does your freedom trump the violinist’s right to life? Thomson thus asserts that the right to life does not necessarily require someone to carry a fetus to term (Thomson 1976). Because every person has a right to bodily autonomy, abortions are permissible in at least some cases.

The Sanctity of Human Life

One of the most pervasive moral arguments against abortion is based on the idea of the sanctity of human life. Those who oppose abortion on religious grounds often equate abortion with murder. Broader concerns warn that if a society abandons the sanctity of human life, then it becomes easier to justify other types of killing (Singer 1993). Within the United States, it was just a decade or so after abortion was legalized that the debate on euthanasia arose.

The content of this course has been taken from the free Philosophy textbook by Openstax