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From a biological standpoint, life does not have a beginning -- it's a continuum. Every living cell was formed from another living cell. Living cells produce more living cells, and later they die. The study of when life began, then, is a question regarding abiogenesis.

(Note: It is very probable that there are Biology textbooks that make the claim that "life begins at conception". This is a reflection of the religious/idealistic beliefs of the author(s) and not scientific.)

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Im referring specifically to the case of when human life begins and embryology texts clearly state that human life begins at conception. The operative definition of human life
here is a genetically complete, self directed, and distinct organism within the mother.

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Sounds like a tumor is a human life. It's human (meaning it has human DNA), and it is living (like every cell in my body is). It is distinct. Self-directed: every cell has the full copy of DNA, and is therefore "self-directed". As I said before, if a Biology text-book claims that "human life begins at conception", it is not based on science, but is the ideological belief of the author(s).

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If I cut off my finger, am I still a person? More or less the same person? Does my finger make me, me? What about my leg? Or my internal organs? What physical part of my body makes me, me? What is it that defines my personhood? Am I less of a person if I become a quadriplegic? I don't think so. So, at least these physical parts of my body are not "me" -- they are not what defines my personhood. But, I posit there is ONE physical part that DOES define my personhood: my brain. If I lose my brain, I'm no longer "me". So, this isn't dualistic, per se. I'm not saying there is a "me" that exists outside of my physical being. But, I am saying that a certain part of my physical being is what defines me. (Actually, it's the activity in the brain that creates my personhood... if my brain is not functioning, I'm no longer "me" either.)


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You are basically defining personhood through functionality. So if someone hits me in the head with a bat and causes me severe brain damage, am I no longer a person? Most rational people would scoff at that notion. I might be an impaired person, but I am person nonetheless. (BTW, full sentinence isnt achieved until well after birth. There are some obvious rather distasteful implications for your argument based on that fact alone).

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If you are severely brain damaged, you are a different person -- but still a person. I have an uncle that was shot in the head and has 1/4 of his brain missing. He's not the same person now as he was before he was shot. But, he's still a person.

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One question: what about cloning?


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I am going to defer on this question because in truth it is a whole other can of worms, although I recognize your reason for bringing it up. If you feel it I need to address it I will, but I am tkaing too long on this post as it is. Hopefully I have provided enough response to keep the conversation going.

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I could have used "twinning" instead of cloning to make the same point. The point is that nothing "magical" happens at conception to create a person. Also of interest, is that conception is not a single point in time, either. It takes up to 24 hours for it to happen.

So, what criteria defines personhood?