Such an assumption does not work when applied to debate against me. My stance is rooted in facts which have been presented to me over time, facts used in the determination of other issues regarding life, humanity, and the law.
These are comprised of three sets.
The first establishes the unborn baby as a living organism. The second establishes that the living organism is of the species homo sapiens and not some other species. The third is that the living human organism that is the unborn baby is a separate and distinct organism from the mother, and not just an extension of her bodily tissue.
For those who, for whatever reason, did not take biology and never sat in sex ed while in school, I'll briefly go over my path to my conclusion.
The characteristics of a living organism are clearly defined by the scientific community. These standards are used for many things besides this argument. Application of these standards is the method by which it is determined whether a new discovery is a living organism, a dead organism, or an inanimate object (an object which was not at some point living.) This determination is used to decide everything from how to pursue a course of research related to a new discovery to issues of environmental protection (such as protected species) and whether a discovered environment could support the existence of living organisms.
To exclude the determination of the product of human reproduction from the scientific standard for determining and defining life would place the discussion in the realm of hedging and intellectual compromise for the purpose of excusing an unethical act. It would be moving the goalposts - arbitrarily placing the criteria for a solid standard out of the range of the currently accepted, evidence-supported area. Doing so sets the criteria and places the standard firmly in the realm of the unprovable and unsupportable, so that unethical actions may appear to be acceptable. I reject arguments based on arbitrary, unprovable criteria.
Characteristics used to define a subject as a living organism are met by human offspring following conception in the following ways:
1) Metabolism - it consumes nutrition, and produces & expels waste.
2) Respiration - though the gas exchange is through the umbilical cord, one still takes place.
* reminder for those who want to debunk the respiration argument - a gas exchange through the cell membrane is enough to label bacteria a living organism.
3) Growth - it takes in material taken in during metabolism is organizes into the organism's body, increasing its mass.
4) Homeostasis - the organism needs to maintain a stable system, or it will die. (Miscarriage)
5) Response to its environment - There is a complex relationship between the body of the mother and the body of the offspring from the very beginning of pregnancy. It is shown in various ways, beginning with the hormonal changes initiated during the process of implantation, continuing after a successful implantation, when the blastocyst secretes the hormone human chorionic gonadotropin (HCG) to maintain an environment conducive to its development. There are other action-response combos like this throughout gestation, right up to labor. The fetus controls the timing of labour by increasing the supply of androgen precursors for estriol production, via activation of the fetal HPA axis.
6) High degree of organization - everything has its place from the time it is just one cell with its various parts to the moment of birth, when the complex human body has all of its limbs and organs. Having vital parts compromised by being misplaced or malformed can severely impact upon the state of the organism, resulting in reduced function, pain and suffering, or even death. The organism has a program (DNA) directing that organization. Abnormal variations in that program can be devastating to the organism's physical form.
7) Reproduction - in this case, cell division at first, and then the formation of sex organs during gestation fulfill this characteristic. It may be of interesting note to expectant mothers that at week 16, the ova form, meaning that when you carry a baby girl, you're also carrying half of the genetic material for the bodies of your possible future grandchildren.
Facts that convince me that an unborn baby is human, and not some other species:
The cells that make up the organization are programed by deoxyribonucleic acid. There are 23 pairs of human chromosomes, that is chromosomes that match the human genome and not that of some other species, in the first cell formed after sperm meets egg. From that moment, the cells are a living human organism, and not some other species. The organism remains homo sapiens throughout its life, at no time having a change of DNA that would define it as anything else.
The fact that convinces me that the unborn baby is an organism which is separate and distinct from the mother is the established fact that the DNA of the organism is not an exact match to the DNA of the mother. Having received half of its DNA from the father, the living human organism growing in the womb is unique and distinct from the mother's body. This creates differences which become more apparent as the body develops, but even from the moment of conception, the code is there. This fact makes the post-conception organism different from the pre-conception organisms from which it formed, in that the sperm and the ovum do not contain genetic code which was not contributed by their respective bodies of origin, and so each individually can be considered to not be independent of the body in which it is contained. This is why I see it as acceptable to use birth control which prevents conception, but not any means of aborting an existing pregnancy.
The above facts, combined, convince me that from the moment of conception, the unborn baby is a living human organism. As such, I believe it should be afforded the same rights as any living human organism, and therefore that life cannot rightfully be ended for any reason which would not be considered to be a valid reason for ending the life of a living human organism after the birth has occurred.
Therefore, in order to convince me and my voting stylus to accept a pro-choice argument, that argument must either
1) Disprove the facts that lead to the conclusions explained above, (prove to me that the organism is not a living organism, not genetically human, or not genetically distinct from the mother)
2) Offer a logical, reasonable explanation which proves that the reason being given for the abortion would be accepted as a legally valid reason to end the life of a grown man or woman.
If you cannot do one of those 2 things, then your argument is bogus and therefore unpersuasive, as it advocates the killing of a living human being for unjustified reasons, and therefore a violation of the most basic human right.
I must note (because I hear the slogan shouted often enough) that there are no rosaries (or any other religious doctrine) included in this argument. My conclusions are not based on religion, so arguing against a religious outlook on the subject is futile. Neither are my conclusions drawn on any belief regarding the timing of the arrival of the soul, the timing of specific development such as a heartbeat or brain waves, or the existence of any disabling condition. My belief on the subject is based merely in whether or not we are dealing with a distinct, living human organism, and the question of whether any given argument in favor of abortion would be accepted at any other stage of human existence, such as during adulthood.
In all other circumstances, the legal standard in the U.S. for not considering it to be a criminal act for one citizen to deliberately end the life of another human being is in defense of human life against the one being terminated. There are variations on this, including self-defense, and the execution of a convicted murderer. Even accidentally ending the life of another human can lead to criminal conviction if it is determined that the death occurred due to negligence on the part of the killer, or due to an assault.
I contend that as human beings, we do not have the right to split hairs and make excuses when deciding whether or not to set and maintain a standard by which we can measure the right of any living human organism to take the life of another, and we certainly cannot apply standards to some living human organisms while denying them to others without first supporting that decision with unarguable certainty. All humans have equal right to life, regardless of age, race, sex, religion, or any other characteristic.
Therefore, my conclusion is that it is heinously immoral to offer the protection of societal and legal recognition of one's inalienable right to life for humans who have finished gestating and been born, but deny it to those who have not. Only in circumstances when the continued gestation of the pregnancy directly endangers the life of the mother due to her physical health conditions is the use of abortion to terminate a pregnancy justified on the basis of existing legal and constitutional reasoning. All other reasons are invalid, and the procedure should be illegal to perform without that justification.
I have a few different email accounts leaving the same set of strawman arguments in reply to this, so I'm going to take a moment and address them.
The first strawman is a reply to only one, not all of the criteria I laid out, as if justifying a kill by stating reasons why one of the criteria alone does not by itself make killing unjust would justify killing an organism which meets all of the criteria together.
The fallacy in that argument is that it simply doesn't address the point. The debater is unable to provide anything which differentiates living human organisms he or she wants to justify killing from living human organisms he or she does not want to justify killing. The argument only draws some similarity between the targeted living human organism separate from the mother, and human tissue which is not an organism or separate from the body from which it originates, and other organisms which are not human.
The paragraph which starts, "The above facts, combined, convince me..." excludes all arguments which do not conclusively disprove the distinction between an organism which meets all of those criteria and an organism which does not.
The second is an argument against imposing artificial life support on a dying human.
Pregnancy is not artificial life support. A dying human will die without outside interference, and non-interference is the argument I've made here. An argument against artificially terminating a pregnancy is not an argument to impose artificial life support, and there is nothing in my argument which leads to yours. Further, it does not justify the 99% of abortions done strictly for the convenience of the mother, not due to any handicap or other gestational issue.
While I am addressing fallacious arguments against this one, I'll also hit another frequently posted reply to it that hasn't shown up here yet.
Numerous individuals have attempted to use cancer as an example of a similarly distinct living organism that it's acceptable to kill.
There's only one problem with that: Cancer is not a distinct, living human organism. It's an overzealously reproducing bad copy of organ tissue. While the product of human conception is distinct from the mother because half of his or her genetic material comes from the father, cancer is simply a diseased part of the host's own body with no foreign DNA. While the product of human conception is biologically organized for functional purposes to grow through a full life-cycle and, under normal circumstances, reproduce in adulthood, cancer has no such function and if left to develop in its predetermined course will grow out of control until it kills the host.
So cancer is neither truly distinct from the host, nor a complete organism. The validity of cancer treatment does not justify abortion.
It's a nice try at an argument, but it's not as well thought out as those using it believe.
Some other posts on Abortion:
Oversight and Abortion: The skeleton in Feminism's closet
If feminism's take on abortion is really about protecting women from dangerous "back-alley" medical practices, why do feminists defend front-door "back-alley" abortion?
Feminism, your hypocrisy is showing.
Feminists defending women's right to bodily autonomy are nowhere to be seen when that right butts up against the abortion industry.
Where are you, NOW?
How much influence has feminism had on today's youth?
This is kinda scary.
Planned Parenthood faces lawsuit for performing abortion on 13 year old and returning her to abuser following abortion.
This is what feminists don't tell you: The abortion industry is just set of another corporate entities feeding off of its consumer base and its workers. Do not be fooled into believing there is anything benevolent about it.
Planned Parenthood defector says loophole lets clinics profit from fetal organ sales
Planned Parenthood uses partial birth abortions to sell body parts.
Second Planned Parenthood Senior Executive Haggles Over Baby Parts Prices, Changes Abortion Methods