Answering the Arguments for Abortion Rights
Part Three: Is the Unborn Human Less Than Human?
by Francis J. Beckwith
Realizing that many popular arguments for abortion rights -- such as some of the
ones found in the first two installments in this series -- have little logical merit,
many philosophers, ethicists, and theologians have presented more sophisticated
arguments for abortion rights. These radical and moderate pro-choice thinkers
agree with pro-life advocates that the abortion debate rests on the moral status of
the unborn: if the unborn are fully human, then nearly every abortion performed is
tantamount to murder. They argue, however, that although the unborn entity is
human, insofar as belonging to the species homo sapiens, it is not a person and
hence not fully human.
Those who argue in this fashion defend either a decisive moment or gradualist
approach to the status of the unborn. Those who defend a decisive moment view
argue that, although human life does begin at the moment of conception, it is at
some later stage in the unborn human's development that it becomes worthy of
our protection. It is at this moment that it becomes a person.
Other philosophers take a gradualist position and argue that the unborn human
gradually gains more rights as it develops. Hence, a zygote has less rights than a
6-month-old fetus, but this fetus has less rights than an adult woman.
In order to understand decisive moment and gradualist theories, it is important that
we carefully go over the biological facts of fetal development. In this third
installment of my four-part series I will cover the facts of fetal development and
some decisive moment theories. In Part Four I will critique some more decisive
moment theories and the gradualist view, concluding with responses to common
questions asked about the pro-life view that full humanness begins at conception.
LIFE BEGINNING AT CONCEPTION AND
THE FACTS OF PRE-NATAL DEVELOPMENT
While going over the facts of prenatal development I will present the case for the
pro-life view that full humanness begins at conception. I will deal with objections to
this view when I critique the decisive moment and gradualist views in both this
article and the final part of this series.
Pregnancy begins at conception, the time at which the male sperm and the female
ovum unite. What results is called a zygote, a one-celled biological entity, a stage
in human development through which each of us has passed (just as we have
passed through infancy, childhood, and adolescence). It is a misnomer to refer to
this entity as a "fertilized ovum." For both ovum and sperm, which are genetically
each a part of its owner (mother and father, respectively), cease to exist at the
moment of conception. There is no doubt that the zygote is biologically alive. It
fulfills the four criteria needed to establish biological life: (1) metabolism, (2)
growth, (3) reaction to stimuli, and (4) reproduction. (There is cell reproduction
and twinning, a form of asexual reproduction, which can occur after conception.
For more on twinning, see below.) But is this life fully human? I believe that the
facts clearly reveal that it is.
First, the human conceptus -- that which results from conception and begins as a
zygote -- is the sexual product of human parents. Hence, insofar as having
human causes, the conceptus is human.
Second, not only is the conceptus human insofar as being caused by humans, it is
a unique human individual, just as each of us is. Resulting from the union of the
female ovum (which contains 23 chromosomes) and the male sperm (which
contains 23 chromosomes), the conceptus is a new -- although tiny -- individual. It
has its own unique genetic code (with forty-six chromosomes), which is neither
the mother's nor the father's. From this point until death, no new genetic
information is needed to make the unborn entity a unique individual human. Her
(or his) genetic make-up is established at conception, determining her unique
individual physical characteristics -- gender, eye color, bone structure, hair color,
skin color, susceptibility to certain diseases, etc. That is to say, at conception, the
"genotype" -- the inherited characteristics of a unique human being -- is established
and will remain in force for the entire life of this individual. Although sharing the
same nature with all human beings, the unborn individual, like each one of us, is
unlike any that has been conceived before and unlike any that will ever be
conceived again. The only thing necessary for the growth and development of this
human organism (as with the rest of us) is oxygen, food, and water, since this
organism -- like the newborn, the infant, and the adolescent -- needs only to
develop in accordance with her already-designed nature that is present at
This is why French geneticist Jermoe L. LeJeune, while testifying before a Senate
Subcommittee, asserted: "To accept the fact that after fertilization has taken place
a new human has come into being is no longer a matter of taste or opinion. The
human nature of the human being from conception to old age is not a
metaphysical contention, it is plain experimental evidence."
There is hence no doubt that the development of a unique individual human life
begins at conception. It is vital that you -- the reader -- understand that you did
not come from a zygote, you once were a zygote; you did not come from an
embryo, you once were an embryo; you did not come from a fetus, you once
were a fetus; you did not come from an adolescent, you once were an
adolescent. Consequently, each one of us has experienced these various
developmental stages of life. None of these stages, however, imparted to us our
Within one week after conception, implantation occurs -- the time at which the
conceptus "nests" or implants in her mother's uterus. During this time, and possibly
up to fourteen days after conception, a splitting of the conceptus may occur
resulting in the creation of identical twins. In some instances the two concepti may
recombine and become one conceptus. (I will respond below to the argument that
the possibility of the conceptus twinning and the subsequent concepti recombining
refutes the pro-life claim that full humanness begins at conception.) At about three
weeks, a primitive heart muscle begins to pulsate. Other organs begin to develop
during the first month, such as a liver, primitive kidneys, a digestive tract, and a
simple umbilical cord. This developing body has a head and a developing face with
primitive ears, mouth, and eyes, despite the fact that it is no larger than half the
size of a pea. Toward the end of the first month (between 26 and 28 days) the
arms and legs begin to appear as tiny buds. A whole embryo is formed by the end
of the first month.
From the eighteenth day after conception, substantial development of the brain
and nervous system occurs.
This is necessary because the nervous system integrates the action of all the
other systems. By the end of the twentieth day the foundation of the child's
brain, spinal cord, and entire nervous system will have been established. By
the sixth week, this system will have developed so well that it is controlling
movements of the baby's muscles, even though the woman may not be
aware she is pregnant. At thirty days the primary brain is seen. By the thirty-third day the cerebral cortex, the part of the central nervous system which
governs motor activity as well as intellect, may be seen.
Despite its small size, the unborn child by the beginning of the second month looks
distinctly "human" (although -- as this article maintains -- it is human from
conception). At this point it is highly likely that the mother does not even know she
is pregnant. Brain waves can be detected in the unborn at about forty to forty-three days after conception. During the second month, the eyes, ears, nose, toes,
and fingers make their appearance; the skeleton develops; the heart beats; and
the blood -- with its own type -- flows. The unborn at this time has reflexes and
her lips become sensitive to touch. By the eighth week her own unique fingerprints
start to form, along with the lines in her hands.
A vast majority of abortions are performed during this time, despite the scientific
facts which clearly show that an individual human life is developing, as it would after
birth, from infant to child to adolescent to