Scientifically, a distinct life is formed at conception in that the zygote is of DNA distinct from that of both the mother and the father. Now if any argument is made for destroying that life, it must be based on the premise that interdependence justifies killing, in which case any of us may be killed, or that some degree of unintentional suffering justifies killing, and based on that logic we could kill anyone who, intentionally or unintentionally, caused us pain, or finally that it is wrong to kill a person only if they know that they are being killed in their last moments, which would justify killing someone if it were done while they were in a coma or done too quickly for them to have any realization of it. All of these arguments are unthinkable when applied to grown adults, so I hold that we have to draw an absolute line as to what a person is. If personhood begins with the formation of the forebrain, then the fetus must, prior to that point, either be dead or genetically part of the mother. If this is not the case, then we can only state that life does indeed begin at conception. That is a phrase that some people associate with religion, but it is actually scientific. Until a scientist produces evidence that a fetus is dead or genetically one with its mother up to a certain point in pregnancy, it is the only logical position to take. A person isn't a "little bit alive". Either they are or aren't alive. Of course, I know from experience that such words make people consider me a religious nut for my views, despite the fact that I held them even when I was a non-religious liberal and the fact that I use very similar reasoning as the basis for opposing the death penalty, so there really is no point in debating the issue, since almost no one changes their views on it. I've learned from experience that pro-choice people stay pro-choice and pro-life people stay pro-life. I have seen every pro-choice case but I find none of them persuasive, and I'm sure that pro-choice people think the same of pro-life arguments.

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"I am a Tory Anarchist. I should like every one to go about doing just as he pleased- short of altering any of the things to which I have grown accustomed." (Max Beerbohm)