(Written in early ’84 after a bit of research confirmation @ the UCLA Medical School)
When an honest disputation arises because of the genuine lack of information on a subject; the logical, civilized resolution is a temporary COMPROMISE until such time as the relevant ignorance is removed. In a free-society democracy such as ours - this is necessarily the matter of course.
One of the most bitter, divisive and often irrational controversies which has confronted the people of this nation over the past few decades is the ultimately meta-physical question of "When does life begin?". This single issue presents one of the most severe tests to our system which maintains church and state as independent entities.
The tension arises, of course, because within the answer to this deceptively simple question lies both a secular legal pronouncement as well as a profound meta-physical definition. The recognition of the dichotic nature of this issue is most important to maintaining a balanced, rational discussion. The fact that there is a meta-physical aspect to the question insures that there can be no totally satisfactory answer found this side of eternity. The reason for this is that meta-physics (apart from-physics as separated from physical TRUTH by the ancient Greeks) or theological/religious beliefs are, by nature (and definition) those aspects of one's world-view which cannot be proven via empirical fact. This being the case, all such beliefs ultimately take on, and are the result of one's personal convictions. The recognition of this concept, and it's embodiment into our society via the founding father's protection of and commitment to religious (pan-philosophical) freedom has served as a beacon of enlightenment unto the world and a safe harbor for the free will of our citizens.
The resolution of this conflict, therefore, must be dualistic, in that it's very nature is thus. That is, there are two aspects to the answer of when life begins, governed by two different kinds of LAW. The more profound, metaphysic aspect which each individual must come to terms with through their own path of reasoning (in conjunction with their god, church and/or moral conscience), and then the governmental/legal pronouncement necessary to guide society towards the most beneficial long-term results.
The legal, aggregate decision is where the concept of compromise must come into play. The point of contention lies, of course, in striking a "Soloman's balance" between the rights of the involved adults and those of a developing human germ combination (a zygote = a human sperm fertilizing a human egg). The elusive definition of when a zygote constitutes a "being" frames the controversy. It is at this point in the discussion where simplistic answers may tend to dominate more reasoned ones. In fact, to admit ignorance on the part of everyone concerned may be the first step towards a mature consideration of the legal/moral dilemma.
The legal responsibility of the government is to preserve "life". The implicit (meta-physical) assumption of western culture is that life begins when a soul enters the body. Because of this meta-physic aspect to the legal question, there can be no absolutely correct and provable definition, hence reason and compromise must be employed.
The fact is, that the biology of the situation is rather complex, and may mislead as well as guide one's thinking along fruitful paths. There is, however, I submit, a logical parallel to be drawn between the beginning of a human's life (the experience and memory of it's thoughts and emotions) and the onset of it's brain-wave functioning! This stage of development seems to correspond as closely as possible to the concept of the entering-in (creation) of the soul. For our essential being, it seems, resides in our thoughts and emotions (cf. the philosopher's quote: "I think, therefore, I am"), which correlates with the concept of our "spiritual" selves having dominion (reigning) over our physical bodies.
This concept may serve as a guide to targeting when removal of a zygote is more justified. In fact, there are numerous levels of functioning of the human brain, as evidenced by progressively more complex electro-chemical wave patterns appearing during development (full insulation of brain cells/myelination not being completed until two years after conception!). However, the fact that the "neural groove" (precursor to the brain) does not begin to form until eighteen days after conception and that the first slow surface brain waves appear at three months give some idea of how much of a "spiritual" vs. physical entity exists at these stages. For, even though the biological term is "embryonic" even before the initial zygote has divided once, such entities correspond more to a used sanitary napkin or "wet dream" aftermath than what non-scientists imagine an embryo to be. <ie. "Portnoy's mother" was NOT correct, by common sensical reasoning.>
The moral/logical responsibility of the government then, appears to lie in providing the best of family planning education and FREE PREGNANCY TESTING encouraged at the earliest possible stage. Research and development of accurate, early detection tests would seem to be in order, also. (As well as better methods of birth control such as RU486 and, of course, male variations of such.)
Addendum
The comprehensive view of this question, however, from a biological as well as psychological and sociological analysis must recognize that Human Life is the most delicate (long-time to maturity/independence) form on earth, and that, all objections aside - THE MOTHER whose body nourishes and helps determine the child's physical/mental characteristics is the judge of last resort as to whether an embryo shall survive or not. If society, through government attempts to legislate it's morality upon a symbiotic relationship (of sorts) which nature/god has evolved into a system whereby the person most naturally & fully responsible for the long-term development of a human child does not have explicit control of whether to continue, her implicit actions (diet, chemical/physical abuse, general physical/psychological health) will accomplish much more harm in delivering deficient individuals than allowing her the chance to plan/control her family (in the long-run, societal result). (Since certain neuro-transmitters from the mother pass through the placenta, unhappy feelings toward a "forced" pregnancy can produce a most unhealthy start/baseline for long term psychological development.)
The personal consequences of course, always remain for the individuals affected, and the ultimate moral consequences are a matter between oneself and one's God, once all things are considered.