Belief 3: It happens between
conception and childbirth
A newly formed zygote:
(commonly referred to as a "just-fertilized ovum")
The process of conception:
There is a general consensus that an ovum and spermatozoon are forms of human
life. People also agree that neither forms a human person.
People have different beliefs about the relationship between conception and
Most pro-lifers believe that human personhood begins during the
Most pro-choice advocates believe that personhood is attained later at
some stage of pregnancy, or even at childbirth.
At conception, a spermatozoon and ovum join to produce what is commonly
called a "just-fertilized ovum." The proper medical term is zygote.
A near consensus exists that:
A zygote is definitely alive: There is a general consensus that a
zygote is: "...biologically alive. It fulfills the four criteria needed to establish
reaction to stimuli, and
The fourth criteria may appear strange. Zygotes can reproduce themselves
through twinning during the first 14 days after conception. That is how
mono-zygotic (identical) twins develop. After 14 days, a yellow streak
appears that will eventually develop into the spinal column. Twinning cannot
occur after that point.
A zygote has human DNA: In almost all cases, at the time of
conception, the 23 chromosomes from the ovum and the 23 chromosomes from the
spermatozoon combined to form a 46 chromosome DNA structure. The DNA is new,
unique and definitely human.
A zygote is a form of human life: A zygote is alive and carries
human DNA. Thus, it is a form of human life.
However, many pro-choicers believe that a zygote is not a human person. They view it as only a potential human
person. They believe that personhood develops at a later stage of pregnancy.
Resolving the conflict over abortion access:
Debates about abortion will never be settled until the precise status of a
human zygote is agreed upon:
Is it, or is it not, a human person?
If it is not a human person, there needs to be agreement on the stage of
pregnancy or delivery that the embryo or fetus attains personhood.
An agreement on these questions would go a long way towards resolving the
abortion conflict. However there would still be disagreements:
If a zygote is considered a person, then abortion is an act of murder.
A case can be made for the criminalization of all abortions.
systems, except for that adopted by the Roman Catholic Church, would say that
an abortion would be ethical when a continued pregnancy threatens the woman's life.
Some would argue that an abortion would be acceptable if continued
pregnancy would very seriously disable the woman.
If a zygote is not a person, then at least an early abortion involves
the killing of a non-person which has the possibility of someday developing
into a person. A good case could be made to allow women to choose freely
whether to have an abortion up to a time when personhood is attained.
The color microphotograph of a just-fertilized ovum shown by permission from Dr. R. C. Wagner,
Department of Biological Sciences, at the University of Delaware, Newark, DE. They have many
other photographs at their Web page:
We thank Dr. Wagner for allowing us to reproduce these microphotographs.
Carl Sagan, "Billions and
Billions", Random House, New York NY (1997), Pages 163-179.