As I said, IMHO. I have, unfortunately been exposed only to Catholic teachings, and as such my views are rather limited. I don’t really believe in souls anymore, so I’m not really all too much into guessing when a soul would be created.
Answers given by different belief systems (religious, moral, legal, scientific) vary from the sanctity of zygotes (extremes of Catholocism), thru conception, implantation, quickening, first trimester, second trimester, various other dates, viability, birth, breathing unaided, being named, being owned by the father, being accepted by the tribe, self-consciousness, puberty!
All of these answers are probably ‘correct’ within the axioms and conclusions of the particular belief systems.
Religious doctrines set out what a good life is from god-given principles- the start of life depends on these principles- different for each religion.
Moral philosophy usually does nothing more than say ‘If you believe this, then you should also believe that’.
Legal systems set a definition which isdefined by the needs of that society- look at the changes wrought on the law by the advance of medical science.
Science, too, has axioms, and it is on these axioms that decisions about the existence of ‘life’ will depend.
Short answer:
‘Humanity starts at the point when the dominant belief system says it does.’
On a kind of tangent, can anybody fill me in on what the fundies (who I think believe that the soul is added at the point of conception) say about identical twins, where the ovum splits into two individuals after conception, does the soul split in two as well? or does God quickly make an extra one.
FWIW, I started out catholic but am now atheist.
From the christian point of view, I would think there is no moment when either life begins or the soul enters. God is eternal, and both the soul and the life have existed since the Beginning and will continue until the End, whatever those may be. There is no conflict regarding gametes which fails to develop, since those events have always been known to God. Also, the soul never transfers to the body or the person. The soul has always been, and always belonged to that person, and is never contained within the flesh.
From a more scientific point of view, I would agree that human life begins when the baby can survive outside the mothers womb, though there is not a specific moment in time when this happens. Again, just my opinion, take it with a grain of salt.
Good question - not too sure how I would answer it…
My own opinion has always been that we cannot tell when “life” begins, so the safest assumption to make is that it starts with conception.
[hijack]Which is why I am opposed (on principle) to abortion.[end hijack]
Gp
Not exactly an answer, but:
Again, I’d think this event would have been known by God. The question places limitations on God that, according to dogma, don’t exist (i.e., God didn’t know this conception would be twins, God has the same temporal frame of reference that you and I have, etc).
One is evil and without a soul, the other is a good person with a soul. This is demonstrated in those pictures where the different halves of the face were combined together forming a “good” and “evil” face. When identical twins form, one is the embodiment of the “evil” face, the other is the embodiment of the “good” face.
I hope to God you’re on medication for whatever afflicts you.
–Tim
yes, me and my litle blue friend work well together.
And on a more serious note, I believe that if souls were going to be made for twins, they would have been made at the point where the god made the other souls, because it is, of course omnipotent, so it knows all. If they were made at conception, two souls would be made. If made when children were born, then no problem.
At what stage does a human being start being human? In my book, when it’s able to formulate a coherent sentence… or about 2 years old.
Until then it’s just something with the potential to be human.
At what stage does a human being start being human?
I was unaware that being a human being is nothing more than a prerequisite to being human. So a brain damaged child who will never, never be able to form a sentance is not human? All the parts are there, they just don’t work right, so it’s not human yet?
A flashlight that is not lit is still a flashlight. Just because the circuit is not completed and the electricity is not creating a light does not mean that it’s not a flashlight. Why is a human being that cannot form a sentance “just something with the potential to be human”?
“No” is a perfectly valid sentence. So is “me hungry”. Whether a person needs to speak, sign, use computer assistance, or telepathically beam the thought directly into my head to get the message across, they still need to form the thought and be able to express it to qualify as human in my book.
I have a very tough definition of what it means to be human.
But please don’t pretend that people with brain damage are anything at all like a Flashlight with no electricity. That’s the stupidest argument I’ve ever heard.
You’re not a human being until you’re in my phone book.
[/Bill Hicks]
Stick around, we can do much better than that 
The word “no” is the representation of an idea. A sentence is a strucure and form in which our words must be molded to make our expressions easier to understand. A sentence is much different than a word.
If you say that being able to express ideas is all that’s needed to be human, than a crying baby that wants something is human. His cry is the equivilant to the word no, or the phrase “me hungry”. Expression and structure are not the same.
Well, I hope you meet your criteria, cause it would be quite interesting for you to be defining human when you are, in fact, not even human by your own terms.
How so? What do nervous cells communcate with (you get one guess)? How brain damage different from a broken circuit?
This is when I resort to the dictionary. Merriam-Webster Online, to be exact.
Main Entry: sen·tence
4 a : a word, clause, or phrase or a group of clauses or phrases forming a syntactic unit which expresses an assertion, a question, a command, a wish, an exclamation, or the performance of an action, [stuff deleted]
See that? Good.
**
Nope. Sorry. A cry is NOT the equivalent of ‘me hungry’. I happen to have a 4 month old baby right here (her name is Samantha, and she is CUTE), and her wail means absosmurfly nothing. It’s impossible to tell if it means she is cranky, hungry, dirty, or unable to cope with the complexities of life. The wail is totally generic.
<sigh> Go away troll.
Ooh look boys and girls! A lightbulb and the human nervous system both use ELECTRICITY! That must mean that because electronic items must be repaired, so can the human brain, so every brain-dead human is still alive, and… and … and…
Look Fromesiter (what the heck does that mean anyway?), the definition of what is human is completely arbitrary. I define it as a being that can coherently express an idea. A generic yell is not an idea, ergo babies (and fetuses) are not human. They’re just things that might be human, one day.
By the same yardstick, humans that suffer brain damage and lose the ability to create and express an idea lose their humanity.
Is it not a short jump from classifying someone as non-human because they cannot compose a coherent sentance to the opinion that the sentance that they do compose is so full of c**p and rubbish and illogical nonsense that it could easily be classified as “in-coherent”.
By this definition, probably half of the SDMB members would be classified as non-human by the other half (certainly in GD :)).
Gp
What sort of ‘things’ exactly?
And
What if they lose only the ability to express the ideas, but can still concieve them? - Stephen Hawking for example; is he somehow rendered human only by his voice synthesiser? (certainly without it, he’d have a very hard time expressing ideas).
As you said, maybe ‘human’ is an arbitrary definition, but to boil it down to essentially ‘you’re human only if I have the necessary skills/tools/patience to understand your expressions’ is putting the cart before the horse.
The potential debate here between Barbarian and Mangetout is looking interesting.
Mangetout- consider this thought experiment:
A man with testes and sperm in one room. A Woman with ovaries and eggs in another. By some means, one of the woman’s eggs is fertilised by one of the man’s sperms. When does human life come into existence. There are three possible answers: 1/ Potentiality for human life was always there, therefore additional human life was always present. 2/ In some way the humanness happenned at fertilisation. 3/ Not yet, sometime later.
If 1/, then we have problems about counting humans. Some Cathlolic theology points towards this option being at least considered- see Humanae Vitae for reasons why artificial birth control is wrong- it uses the potentiality argument. If 2/, the questions is ‘What happenned, what is different?’. If 3/, then conception is not important and humanness starts later.
The point is, if you are accepting any of these save 1/, then you have entities that are not human that then become human- ‘things that might become human one day’.
Unless you are arguing for potentiality which includes all possible sperm/egg contacts in future, then there are ‘things’ that become ‘human’.
Of course we (humans) are, at least in part, organisms that will become things one day.
To Barbarian:
There is a good argument that all things of human inherited provenance or with potential human form are best decribed as human. Many people would consider their severely brain damaged relative human, even if they were unable to communicate in any meaningful way. The concept of personhood is possibly what you are looking for- the ability to interact as a person with other persons. This is defined very differently to ‘being human’ and is a useful distinction.
For instance, it is possible to feel emotions towards someone you remains very human- they are a life form born of other humans, but who have no personhood.
The moral question that needs to be answered is ‘How should I act towards an ‘X’’; the decision may be different when the ‘X’ is a person than when the ‘X’ is merely a human.