AbOrTiOn, good or bad?

Getting an abortion should be no more an issue than having an unwanted growth removed from one's backside. It is only the theological roots of our moral values that makes an abortion more significant. Let's face it, if we (Americans) weren't in the process of emerging from the under the thumb of Puritannical views of sex (ie, abstinence before marriage, sex is for procreation only, missionary position, etc.), would abortion be such a controversy?

I do think special status should go to an actual life. I would maintain that this occurs at the moment when consciousness/experience/any-kind-of-feeling-at-all arises. I do not know when this is, or even how it happens.

I'd agree that after this point the question becomes substantially more complicated, but until that point we're really talking about tissue--living tissue with the potential to become a human, but tissue nonetheless.

I was not aware that we knew what parts of the brain are responsible for the ability to experience. I didn't think we knew why experience should be necessary for the working of the brain. I thought, for all we currently know, my brain and body would act just as I do, without 'me' experiencing it. I shouldn't think I would even believe in the idea of experience if I didn't experience myself and know it were possible.

And if we don't know why we experience, or what experience is, how can we know when, or how, it arises?

This argument excluded ( since all the activists seems to have been defanged) , why do people argue continuously about things when they know they'll never be able to convince the other person? Both arguments for and against abortion are logical and founded on goodwill and morality.

I'm confused about your terminology. 'Experience' is physiological, not metaphysical. We experience the world through our senses which are part of our nervous system and operate on fairly well understood electro-chemical reactions. The sensory input goes to the brain where it is either ignored, transferred to short-term (or working) memory and, depending on that sensory input's perceived importance or its connection to previously encoded sensory input, either forgotten or encoded to long-term memory. Theoretically, if technology and neurological knowledge were advanced enough, I could surgically remove your brain and, by carefully creating and controlling nerve impulses to your brain, make it so that you would never know the difference (ie, make you think you still had your body, lived your life, etc.--a little like The Matrix except you would just be a disembodied brain).

Now if you're talking about the soul, why worry anyway--the soul's immortal (but this, however, makes the debate a theological one).

Always difficult to find the right word for this concept, I meant experience as a noun, not a verb, but admittedly the concept is still vague. Dawkins uses the word 'consciousness', and describes it as 'the most profound mystery facing modern biology'; a religious/spiritual person might call it a 'soul', or 'spirit' (which may or may not be immortal, or theological, since it does not imply to me the existence of any God/gods).

It is, for me, the prerequisite for existing as a moral entity. Which is, of course, problematic, it being a mystery 'n' all...

I'm not familiar with Dawkins, but it sounds metaphysical. It begs the question, though, of whether the abortion issue should be resolved in terms of mystical speculation or empirical evidence.

In the end, it seems more logical to base rules on what we can observe and test rather than on what we cannot observe or test.

Perhaps, but if we know we lack the ability to observe and test the key factor in a problem, the most logical course of action seems to me to be to focus our effort on finding a way to observe and test what we currently cannot, rather than resting on the laurels of what we can. In the meantime, we should decide which side of the argument to give the benefit of the doubt. I'd would recommend the side which would cause the least harm were it wrong.

What are the 'necessary parts of the brain'? How do they differ from the unnecessary parts of the brain? Is it not possible that any brain whatsoever could imply a degree (however small) of consciousness?

The lobes of the cerebral cortex would be the necessary parts. Consciousness, which basically refers to the knowledge of one's own existence (as it's being used here), doesn't seem to exist until sometime after child birth (well after the cerebral cortex is developed and active--it seems we actually have to learn that we exist).

Now, as to whether or not a brain of any size implies a degree of consciousness--probably not, but it's not so much size that's important as is the presence of the proper features. Consciousness seems to depend on the cerebral cortex. Some animals (insects, most fish--I think, and some lizards) don't have a cerebral cortex at all. Mammals do, but not as complex as the human cortex (though there is a lot of evidence that the other primates are capable of self-awareness, too). You can sort of think of the brain as a computer and consciousness as a program. Unless the computer meets the system requirements of the program, it's not going to be able to run that program. Our brains don't meet the system requirements of consciousness until a certain stage of development.