WHEN DOES A HUMAN LIFE BEGIN TO BE A HUMAN LIFE AND END?
HUMAN LIFE IS A CONTINUUM FROM THE MOMENT THAT A SINGLE-CELL EMBRYONIC ZYGOTE, AN ORGANISM WITH 46 CHROMOSOMES, THE NUMBER REQUIRED OF A MEMBER OF THE HUMAN SPECIES COMES INTO EXISTENCE EITHER NATURALLY THROUGH THE PENETRATION OF A SPERM INTO AN OOCYTE (FERTILIZATION), OR THROUGH THE LABORATORY MANIPULATION OF AN OOCYTE, SUCH THAT THE OOCYTE, NOW A ZYGOTE, IMMEDIATELY PRODUCES SPECIFICALLY HUMAN PROTEINS AND ENZYMES, DIRECTS HIS/HER OWN FURTHER GROWTH AND DEVELOPMENT AS HUMAN, AND IS A NEW, GENETICALLY UNIQUE, NEWLY EXISTING, INDIVIDUAL HUMAN INDIVIDUAL.
HUMAN LIFE ENDS, AFTER HAVING BECOME FULLY DEVELOPED IN THE WOMB, WHEN THE UNITY OF THE ACTION OF THE COMPLEXUS OF BRAIN, HEART AND LUNGS HAS CEASED TO FUNCTION.
When Does a Human Begin?
November 18, 2011 by Gerard M. Nadal
When one considers the ethics of manipulation, the question of whether we ought to, or whether we may manipulate an organism or entity depends on the answer to the first and most fundamental question:
What is it?
Ascertaining the identity and status of the object of our intended manipulation is essential.
In the fields of obstetrical medicine and reproductive medicine the ethical debates have raged for four decades. Enlightened discourse between opposing parties must assume good motives by all involved, and then go about asking the essential questions, following where the truth of science and reason lead.
Many claim that life begins at some point distant from fertilization, always beyond the point at which they propose some manipulation (abortion, embryonic stem cell culturing, etc…). There are always a list of biological functions that are given to define when human life begins: Cognitive capacity, etc.
The simple biological truth of the matter is that the Cell Theory states that all cells arise from pre-existing cells. There is no blackout period between sperm and egg uniting, and then the emergence of ‘life’ at some point distant.
The Carnegie stages of human development indicate that human development begins in the zygotic stage. Then there is the assertion of developmental biologist and leading textbook author in the field, Scott Gilbert. In his text, Gilbert takes us through the life cycle of a dog. His text, Developmental Biology, is arguably the leading text in the field. According to Gilbert:
“Traditional ways of classifying catalog animals according to their adult structure. But, as J. T. Bonner (1965) pointed out, this is a very artificial method, because what we consider an individual is usually just a brief slice of its life cycle. When we consider a dog, for instance, we usually picture an adult. But the dog is a “dog” from the moment of fertilization of a dog egg by a dog sperm. It remains a dog even as a senescent dying hound. Therefore, the dog is actually the entire life cycle of the animal, from fertilization through death.”
First, note how he sets the word dog off in quotes at one point, to communicate the very essence of the organism:
But the dog is a “dog” from the moment of fertilization of a dog egg by a dog sperm…
The same may be said of all vertebrates, including cats, giraffes, chimpanzees, and humans. Substituting the word human for dog in Gilbert’s analysis gets to the heart of the matter. We are human for our entire life cycle. We are whole and complete in form and function at every stage of our development, for that given developmental stage. The prepubescent child is fully human, even though they lack the capacity to execute all human functions, such as abstract reasoning, or reproduction.
In the same way, the early embryo is alive and fully human, though it has not yet executed all human organismal functions.
Photo via: embryology.med.unsw.edu.au
- Gerard M. Nadal
A correlative question is: when does a person begin to be a person?
The theologian would respond that human life begins with the union of the human soul with the human body. When that occurs in time only God knows, but it is reasonable to assume that it begins with EITHER the fertilization of the egg by the spermatazoon, or by the manipulation of the oocyte in the laboratory resulting in the presence of the 46 chromosomes.
The philosopher might respond that according to the principle of individuation, the moment the organism acquires sui motio, the ability to activate itself, it acquires personhood, perhaps between Carnegie stages 7 and 8 in the above scale, although some would argue that personhood is coexistent with life.