Among Embryologists and other scientific specialists with no vested interest in abortion there is no controversy about when human life begins, it is unanimously at conception. Some critics argue that the unborn are not human beings whilst others grant their humanity but argue that the unborn ought to only be granted human rights when they acquire a particular function. That may be the ability to feel pain, experience self-awareness or any number of different abilities. The problem with this is that every acquired characteristic is just a subjective line in the sand, and it could just as persuasively be argued that a working renal system or eyes are the points at which we grant the unborn human rights. There is no particular function that suddenly bestows value upon the unborn, and to present this as the case is not an argument but rather an assertion. Moral consistency dictates that either we have human rights in virtue of being human beings or we don’t, not because of an acquired function at some arbitrary moment. This means that if the unborn are humans then they warrant the human right to not be intentionally killed. If the unborn isn’t human then we are left with a strange question. How exactly can human parents produce offspring that isn’t human but later becomes so?
What is conception?
Conception is the moment when the female egg is fertilized by the
male sperm, this brings into existence the zygote. The zygote is a
genetically distinct, living and growing human. All of us without
exception began our lives as a single cell zygote, we began our lives as
a human being and will remain so until death. Referring to the human
zygote Dr Keith L. Moore states that ‘The cell results from
fertilization of an oocyte by a sperm and is the beginning of a human
What do the experts say about when human life begins?
Dr Alfred M. Bongionni, Professor of Paediatrics and Obstetrics at the University of Pennsylvania -
‘I learned from my earliest medical education that human life begins at
the time of conception…I submit that human life is present throughout
this entire sequence from conception to adulthood and that any
interruption at any point throughout this time constitutes a termination
of human life…’
Professor Micheline Matthews-Roth, Harvard University Medical School – ‘It
is incorrect to say that biological data cannot be decisive…It is
scientifically correct to say that an individual human life begins at
Dr Watson A. Bowes, University of Colorado Medical School – ‘The
beginning of a single human life is from a biological point of view a
simple and straightforward matter-the beginning is conception.’
Professor Hymie Gordon, Mayo Clinic – ‘By all the criteria of modern molecular biology, life is present from the moment of conception.’
Should the unborn have the benefit of the doubt?
As the above quotes demonstrate, experts agree that human life begins
at conception. However even if we didn’t have this knowledge
we should grant the unborn the benefit of the doubt, rather than being flippant
about when human life does or doesn’t begin.
A thought experiment
Imagine you were driving along a road in the dark and you saw a
shadow up ahead, should you drive into it, or press the brakes? Most
people would give the benefit of the doubt to what could be a person in
the road and do what they can to avoid a collision. If we don’t give the
benefit of the doubt to the unborn as Randy Alcorn says ‘we are saying,
this may or may not be a child, therefore it’s all right to destroy
There is unanimous scientific agreement on when human life begins, yet
even if we didn’t have this information it makes sense to grant the
benefit of the doubt to the unborn even if we were unsure. The
scientific data when combined with the philosophical case is extremely persuasive.
There is simply no morally significant difference between us before
we were born and the adult we now are. Obviously there are differences
but as Stephen Swartz points out in his SLED acronym, the embryo for
example differs only in size, level of development, environment, and degree
of dependency . None of which provide sufficient justification for
abortion. From the point of conception we are humans, less developed,
less able, less talented but no less human but equal through our common
human nature. Any interruption of the process from the point of
conception results in the death of a human not anything else.
The burden of proof is on those in favour of killing the unborn to
present proper justification for taking the life of an innocent,
distinct, whole and growing human entity. Without which abortion is
simply an unjustifiable moral wrong that ought not be permissible. Are we unsure about when human life begins? No, but even if we weren't it makes sense to grant the unborn the benefit of the doubt and not practice something that results in the termination of what could have been the beginning of a human life.
 – Moore, K, L. (1977), The Developing Human: Clinically Oriented Embryology, 2nd ed, Philadelphia, Penn: W.B. Saunders.
 Alcorn, R. (1995), Prolife answers to pro-choice arguments, Multnomah, Oregon.
 Klusendorf S. (2009) The Case for Life, Crossway.