"If one acknowledges that the embryo or fetus might be a human life, isn't that a strong reason not to abort it?"
That seems rather to partake of a fallacy of equivocation at a minimum and maybe a couple of other informal fallacies which refuse to spring to mind at the moment. A single skin cell is both human and alive, yet they die regularly and become part of the epidermal layer which is sloughed off during normal activities. I think what you mean is that an embryo or fetus might be a "person" and that I would flatly deny.
"Medical science tells us the embryo is like a blueprint with all the building materials at hand and a full construction crew in place. In fact even while the zygote is still in the fallopian tube, the construction crew is already furiously at work. Is there any point before birth (or even after) that is more significant than that first moment? "
I would assert that in forming a person there is no point that is more particularly important than any other. Estimates for the number of zygotes which do NOT make it to parturition range as high as 80%, many zygotes dying soon after fertilization and others failing to implant for any of a variety of reasons. I.e., known miscarriages are but the tip of the iceberg, so to speak Even at birth the body and brain are far from complete. Indeed human infants are, compared to our nearest primate relatives born prematurely. In any event, in addition to the ossification of the skeleton, the brain has to finish its wiring up, and to wire itself properly it requires environmental stimulation. We literally, to take some small liberties with the science, have to teach ourselves to hear and see as well as control our voluntary and semi-voluntary muscles. And of course we have to learn a language and a culture and most usually a religion. All of this requires environmental input. Indeed environmental input is absolutely critical at some points if the process is ever to occur at all. I.e., a young child denied proper social contacts will never learn to be "human", never learn to speak, never learn how to "properly behave". "Feral" children are, fortunately, rare, but the lessons we learn from them are utterly clear: Persons are MADE, not born, and certainly not merely conceived. It takes years to go from a mass of rapidly reproducing and differentiating cells to a person, a "human being", and it takes far more than just genes to make it happen. Genes are a necessary but NOT a sufficient condition for making a person.
I think it a safe assumption that you believe each person, or each human perhaps, has a soul. When is it that you suppose "ensoulment" occurs? Does this have anything to do with your judgments of when it is that a "person" or a "human being" "is"?
San Diego, Ca.
"If anyone can show me, and prove to me, that I am wrong in thought or
will gladly change. I seek the truth, which never yet hurt anybody. It is
only persistence in self-delusion and ignorance which does harm."
Thank you for your e-mail, also on Carl Sagan & the Moral Law. You make some important points which I don't know whether I can answer or not. I will post your letters with whatever comments I can. Maybe someone else will want to jump in as well. I do have a question about this:
"Estimates for the number of zygotes which do NOT make it to parturition range as high as 80%, many zygotes dying soon after fertilization and others failing to implant for any of a variety of reasons. I.e., known miscarriages are but the tip of the iceberg, so to speak"
I have heard statistics like that, but have not been able to find the studies they are based on. I asked a doctor friend who told me figures like that were in the medical textbooks, but he had not heard of the actual studies, especially about zygotes conceived but which fail to implant. Do you know where those studies can be found?
Fr. Phil Bloom
Response from Michael (A study which seems to support the 80% "spontaneous abortion" rate)
Did Aquinas say a baby has no soul until forty days (for a boy) or eighty days (for a girl) after conception, so abortion is okay before those times?
From Sarah: "Do you honestly believe that making abortion illegal will solve the problem?"
From Abortionist to Catholic: Bernard Nathanson, M.D..
Abortion and Forgiveness
See also: What Percent of Embryos Implant?