Amos: "HEll, bruce, if you define your terms right you can make dairy farms look like charnel houses. The assertion that from conception on the individual zygote has full human nature is specious. Folks who choose it as a belilef, in the absence of some better analsyis, are free to live by it"

Ok, let's look at this. I have posited a solid scientific rational argument for defining the new life as human from the moment of conception:

1. when the gametes from both parents fuse, a new life with a unique DNA is formed, even if this life consists of one cell at the beinning. This unqiue DNA did not exist before the gametes of both parents (sperm & egg). This moment is called conception.

2. This new life carries the genes / DNA of a particular species. As I've already said, when a woman is expecting, what is she expecting. If we wait around 9 months, what do we expect to be born? An elephant? An aardvark? A sand eel? Hopefully not, except perhaps in the Twilight Zone!
A chimpanzee shares 98% of our DNA, but look at the difference that 2% makes!! Are chimpanzees human (they deserve compassionate treatment, sure, as do all animals, but they are not human). The 'zygote' as you like to call it, already shares 100% of our DNA. It will not develop / grow up to be a chimpanzee, but a human.

3. From the moment of conception there is a continuum of development until death. At no point in this continuum can the person be considered more or less human. If they become ill or sick, as some have argued, have they transmorgified into elephants? Or sand eels? or chimps?

This is a perfectly rational science-based perspective.

There is also a religious perspective, for the religious minded: that God breathes a new soul into the new life at conception, and from that moment the time of death is at God's disposition, when He calls that person from this life.

Now, the religious perspective has been rejected by several on this thread. Fair enough, us religious lefties can't prove there is a soul, or life after death or even a God (at least by scientific empirical means) so I suppose it's a lot to ask the Doubting Thomases since we don't have the holes for them to put their hands in.

But I have already outlined a solid scientific rational argument more according to the tastes of those so-inclined, and apparently that's not enough either. So here's a case where neither science nor rationality nor religious belief is going to have any influence on the thinking and behaviour of those who choose to believe what they wish, despite all evidence to the contray.

Fine, but at least stop saying religion is a waste of time beause it is not rational. Neither is the pro-choice argument. It is based on beliefs, not on empirical science or reason.

These beliefs in turn form the basis of laws / court rulings by which we must all live (i.e we must respect the law as it stands or be in breach of it). So beliefs are capable of forming society, and not always religious beliefs either!

(Which is not to say the pro-choice argument is not pragmatic: sure, it's far more convenient to just make all these people disappear instead of overhauling our society so such a scenario becomes almost - or hopefully completely - unnecessary)

As for a woman having control over her own body, fair point. I would not advocate anyone not having control over their body (which is one of the reasons I would be opposed to murder, slavery, rape, torture etc.,). Problem is, in the case of abortion, control is being extended over SOMEONE ELSE'S BODY. What about that person's own right to have 'control over their body'?

The 'pro-choice' lobby seem to regard the unborn child as a clump of tissue, a by-product of bodily functions...basically like a piece of s***. Denying someone the 'right' to abort then seems as unreasonable as denying someone with constipation a dose of laxatives. Trouble is, it's not a piece of s***, it's another human being we're talking about here.

Whether I like it or not, that's the rationality of the situation.