I'm afraid you've gotten bad information.  Liberalism (in a philosophical sense... not political) doesn't depend on subjective truth.  It is typically the acknowledgment of the objective truth that much of the human experience is subjective, and that there are often multiple ways of doing something, all of which are valid.  It also tends to value individual freedom above group conformity.

Both the egg and the sperm are alive before fertilization.  Scientifically speaking, life doesn't begin.  It continues.  As far as the individual that will grow into a human, it is alive in a scientific sense from conception.

Perhaps God considers the loss of 10,000,000 potential humans as collateral damage ?  Besides life is cheap when you are a God who can create humans out of thin air.

What is life?

Are you thinking of abiogenesis?

A man after my own heart....

Thank you guys for some interesting replies. 

I don't mean to send this thread down the political issue of abortion as that was not my intention. 

hamby, your comment of "life does not begin...it continues" is a point of view I never really considered (I wonder how that would apply to the political debate?).

Sperm without and egg or vice versa is not life.  It is potential life yes but one without the other is basically nothing. 

But it is Kelly's comment that is more to the point.  When conception happens, is that human life?  If anyone is about to become a parent, is the life within the woman life now?  Was it an "it" or life when it was conceived?  I'm guessing here that both Sapient and hamby believe it is life at conception...Kelly not so much?  Or did I get you wrong Kelly?

Is there a debate on this when it does not involve the political issue of abortion?

I imagine there's a lot of philosophic debate among embryologists. Among the general population? Not a lot, though I got into a great discussion about similar things once while getting stoned with some friends.

I imagine there's some point after the first mitosis of the zygote and before high school graduation when self-awareness creeps in. That's the only point I can think of that really distinguishes the life of of a "person" from the life of two haploid cells in the instant before fertilization. Sure, there's lots of other differences. But really, life is life. If you decide that eggs and sperm aren't "life," then what makes the zygote special? What makes the fetus special? How is that life qualitatively different from the two star-crossed gametes?

I'd tend to agree with Kelly on this one. The viability of the fetus is really the determining factor. Until the point that the fetus is able to survive outside the womb, it is essentially a parasite in the womb of the host mother. It's an arbitrary distinction, but it's the best I think we can do for now.

Hey, Razorphreak, a serious question: I'm assuming you believe we are inhabited or are otherwise infused by a soul. Is the soul distinct from the body? That is, does it pre-exist, or is it something that grows with the body? Basically, what's the mechanics of the soul/body duality?

There's no hidden motive for me asking. I'm just curious, and I believe this has a bearing on the topic at hand.

But isn't the possibility for life mean just as much as survivability?

I'll be honest, I don't really see the relevance only because I honestly started this thread looking for different viewpoints on the subject of "when does life begin."  I'd much rather start a new thread on theistic questions regarding a soul.  I really wanted to keep this thread free from atheist vs. theist regards.

But one without the other is nothing no?  Sperm has no purpose without the egg.  And the egg has no purpose without the sperm.  Neither can be called "human" until they are together and the magic happens (don't flame me on that statement ok...I'm talking figuratively).

That did get me wondering...how are sperm and eggs considered "alive?" 

My question to you is since cells/DNA are part of a unique entity we'd call a human being, doesn't that mean those cells/DNA are not life but part of a life?  When sperm and egg come together, do they not create a new unique entity?  So since we are talking human life, parts of the whole, like the thousands of skin cells you shed daily, how can they be considered "life" as well if they are not unique entities themselves (that is they serve no purpose alone/seperated)?  No "theism" in my questions...I'm really intriguied by this line of thought that you present.

I think that's a whole 'nother can of worms. At that point, "possibility" becomes any logical combination of gametes, or even artificial clones. At what point is "potential" and "possible" worth defending?

For instance, females spontaneously reject fertilized eggs all the time. An early-stage foetus might be discarded during regular menstruation, and the female won't even realize she was pregnant. That discarded egg has just as much "potential" as a fertilized egg that attaches to the wall of the womb, and is later carried to term. Are we letting millions of children die each year, simply because we don't do more to ensure every fertilized egg is carried to term?

I'm not discussing the viability of those zygotes. The body rejects them for a reason, in most cases. The lives we would be "saving" by ensuring every zygote becomes a foetus might not be worth saving.

From a biological standpoint, we have an obligation to our species. (Well, "obligation" might not be the correct word. But I haven't had much coffee yet. I can't use my words good until I drank me some coffee.) That obligation is greater than our obligation to an individual.

That leads me to an interesting question: How and why did we evolve the desire to not be pregnant? Even to the point of discarding the product of our own reproduction?

The relevence is limited. Mostly, it's just the "other side of the coin." I was just trying to indulge my curiosity. But, you are absolutely correct. No need to derail a perfectly intelligent conversation to satisfy my own selfish desires. I retract that question for now, with the hope of getting back to it on another thread, after we've played out this thread.

Depends on if we are attempting to alter what happens naturally I suppose, but then that's the political argument I think.  Humans naturally remove both for all manner of purposes.  There is no need to label it good or bad since that is part of nature and nature does not distinguish between the two.

I'm assuming you are talking about the continuation of the species, not your blood line, that "obligation."

I don't think we ever "evolved" out of that desire...wouldn't it be more an issue of societal pressures rather than natural desires to reproduce (that is, at least to those who can reproduce)?  I mean if you cannot financially afford 15 kids, I don't think you'll continue having sex with reproduction in mind right?

The human body. 

The cell is nothing without it.  What I'm trying to grasp, if this was hamby's point, was while the cell may be "alive," is it considered "life."  Perhaps one reason for what has me stumped is when I'm thinking the term "life," I'm thinking human life which is what I meant by the OP.  But I digress that "life" can yes be nothing more than one cell.

hamby, et al, does it make any difference if I were to have specifically asked "when does HUMAN life begin" in your responses (although I do believe Kelly was responding to exactly that point)?

Precisely. If someone chooses to not reproduce, even to the point of aborting a foetus, they are obviously not following some innate desire to reproduce their own specific genes. However, very few people desire to see the end of our species.

I think you've hit the answer to my question about evolving a desire to avoid breeding. Societal pressure seems to be a big evolutionary influence at the moment.

Anyway, that's completely tangential to your original discussion. So, to the real point:

So two gametes are "nothing without [the human body]." How about the zygote? Is it also nothing? How about the embryo? The foetus?

I think that was Kelly's point -- that survivability is the best cutoff we have. It's arbitrary, but pretty much any definition of the beginning of "human life" is arbitrary. As Hamby points out, it's really a continuum. There's no instant in which something goes from non-life to life in the reproductive phase. It's all just "life." It appears that any other question becomes one of practicality, ethics, or politics. Ignore the ethics and the politics, and you're left with practicality. With that, I believe survivability is the only real option as a definition.

At least, that's how I see it. Perhaps I'm missing options, though.

I'd be careful here. I believe it is an error to think humans are unique in their ability to reason. Many other species have demonstrated the ability to reason to one degree or another. Humans have just proven to be particularly clever at it. Just as cheetahs are the fastest sprinters, it doesn't mean other animals can't run.

We have simply specialized in being generalists.

Honestly, this is something that I often wonder about. How do you define the difference between a human's ability to reason and the ability of animals to reason. Regardless, I find the human brain to be the aspect of humanity that distinguishes it from any other life forms. And I think that it is the best decider for the beginning of a life. Although I will admit it remains somewhat arbitrary.

The problem you're going to run into is that you're mixing philosophy with science.  The sex cells are alive by all scientific definitions.  All of them.  By the way, did you notice that even though I addressed the issue of reproduction, someone still brought it up?  It's almost as if people don't read the posts...  Anyway, that's neither here nor there.

Alive = life.  It's just two forms of the same word.  If I have life, I am alive. 

As I've said before, this question is mostly semantic, and frankly, I don't give a damn.  I don't know if you've been following some of the other threads, but there's been a lot said recently about the concept of a species.  The uncomfortable truth is that "species" is  (and I'm going to keep saying this until someone notices) specious.  Life is a continuum.  Zoologists invented the taxonomic classifications before they knew about DNA, or that all life was related to a common ancestor.  Though the divisions of species work well enough, they are far from exact.  This is because there is no objectively real division between life.  You and I have over 90% of the same genetic material as an oyster.  Statistically, the differences between any two animals are so slight as to almost be insignificant.  Having said that, of course we can look at a human and say, "That's a human."  For all intents and purposes, you and I share so many similar qualities that there's no problem saying we are the same thing, but from another point of view, we're not.  My genome is not replicated by any other organism on earth, and neither is yours.  We are discreet entities that have never existed before and will never exist again.  Furthermore, either one of us, were we to reproduce (I have no idea if you have kids) could, in theory, become the father of a new "species."  Since species are only identified in reverse, we have no way of knowing for many, many generations.

I know I'm not really answering your question, but that's because your question is somewhat misplaced.  Taxonomy, though it represents real phenotypic and genotypic differences between discreet genetic "packages," is an artificial construct that makes it easier for scientists to conduct research.  Politically, the definition of "human" matters quite a bit, but scientifically, it's nothing magical.

I need to point out, just to be thorough, that there are certainly quantifiable, real differences between say, eukaryotes and prokaryotes.  It doesn't take a rocket scientist to realize that there are plenty of clear cut divisions that enable us to construct taxonomic boxes for things.  However, at the fringes, it gets really nebulous. 

A blastocyst formed in a human female will, if implantation is successful, form an embryo and a placenta, from the embryoblast and trophoblast, respectively.  To a scientist, it's a blastocyst.  Is it human?  I dunno.  It's a blastocyst.  When it's an embryo, is it a human?  I dunno.  It's an embryo.  All of these terms have exact scientific meanings, and refer to a very specific entity.  As far as I know, scientifically, a life form becomes its taxonomic name after birth.  In other words, if you show me a mass of cells from a chimp and ask me to identify it, I'll do some experiments and tell you it's a blastocyst.  If it's from further in pregnancy and has certain developmental characteristics, I'll tell you it's an embryo.  If you ask me what species produced it, I'll tell you a chimpanzee.  Show me a baby chimp, and I'll tell you it's a chimpanzee.  At each stage, we have a precise way of identifying the thing.  To call a blastocyst a chimpanzee is a scientific mistake.  Since humans are just another life form in the same tree, I can't think of any reason to treat humans differently.

I saw the comment about semantics in your original post as a clear means to prevent anyone from attacking the whole in your definition. "A sperm cell meets almost all of the requirements for life, but that's just semantics." A sperm cell is neither alive nor a life.

No, I'mthinking.  (Ironic name...)  Read what I'm about to write very carefully.  Sex cells are haploid.  Unlike polyploid cells, which have two or more homologous copies of each chromosome, haploids have one.  This is not a problem for the definition of life, for there are many kinds of single celled organisms that do not reproduce by meiosis.  Horizontal transfer and binary fission are also common among single cells.  It is not restricted to prokaryotic cells, either.  Some eukaryotic cells undergo cytokinesis instead of mitosis or meiosis.  In short, gametes are unusual in sexually reproducing organisms because they are haploid rather than diploid.  However, this has no particular bearing on the existence of their metabolic processes, only on the chapter of the science book they're going to be mentioned in.

A sperm cell meets all of the requirements for life, and one of them has an asterisk because it is an entirely different kind of cell than any other in the organism.  I'm not going to argue with you about this because there is no argument to be had.  If it is a cell, it is alive.  Period, end of story, fin, fine, done.  Your lack of scientific knowledge is a problem for you, but I'm not going to get into a debate where the answer is easily apparent for anyone who wants to crack a textbook.

I don't care much for this language.  Although it's technically true, it's missing a very important point.  The human body is clearly programmed such that each sperm is not destined for an egg.  Even in the ejaculate of a successful copulation, only one out of millions of sperm will fuse with the egg.  Sperm, from a biological function perspective, are meant to be thrown away.  We have a mechanism for re-absorption of unused or non-motile sperm into the body.  We have nocturnal emissions.  There are many ways in which sperm can become separated from the body, and as a functional argument, are doing exactly what they are "supposed to do," even without fertilization.

A severed finger is not part of a biological design.  It is an accident that can lead to the death of the organism it was attached to.  Furthermore, a severed finger is part of an organ -- the skin -- and contains elements of larger structures, like muscles, tendons, and bones.  It is not really a "whole" anything.  A sperm, on the other hand, is a self sustaining, organized, metabolizing singular entity.

Oh, and just to reemphasize the point, a sperm has a longer lifespan than some animals.

Sex cells DO make copies of themselves - they combine, grow into larger multi-cellular organisms, which, among other things, produce more sex cells.

Many life-forms go through stages in their life-cycle where they could barely be recognised as living things - spores, seeds, pupae. Would you classify these as neither alive nor living things? If not, does that mean that living butterflies arise from non-life?

'Life' is a process. We perceive certain apparently discrete entities as individual life-forms, but few, if any of these are truly independent entities. No sexually reproducing can make a copy of itself independently of other living entities, so are they not alive?

The point about symbiotic organisms illustrates that this division into 'individual' things is not always unambiguous, just as with 'species'.

I think that sperm, ova, zygote, embryo, fetus, etc for a particular 'species' are all part of that particular process. In the case of our own 'species', they are all part of the particular sequence of fertilization, growth, maturation, breeding, etc that is a 'human life'.

When we talk about a human life in the sense of an individual, conscious entity, the characteristics that we think of as defining a person, typically grow from virtually zero at the point of fertilization to recognizably 'human'  over the growth process, roughly continuously, albeit with some major spurts of growth at various points in the time-line of an individual human entity.

For many practical purposes, especially legal, we have to draw lines somewhere, but this inevitably is to some extent arbitrary.

EDIT:

I think the question of 'soul' is actually quite relevant here, because it is the idea of an 'essence', some discrete attribute of an entity that is either there or not, such as a 'vital force' making the difference between living and non-living entities, or 'mind' in the dualistic sense, and, of course, the 'soul', that leads to this sort of question. The reality, as our scientific investigations continue to reveal, is that the attributes we try to 'explain' with such concepts are emergent properties of particular complex structures and processes, not separate things in themselves.

Wow you all, thanks .... And the "source" of all this great posting (you that are alive with consciousness) is what ? The Source ???

Basically what I am reading here is how we divide and measure the ONE. That is what we do, in all of science and philosophy. Just as I choose the word "source", I realized it is in error, for lack of knowing "everything". All I am left with is all is ONE , the father / mother TOTAL cosmos is alive, in a linguistic sense !  Now what, dogma ? !!!  Call it spirit, ? Does life come from un-life ?  A beginning ???  Life  / Dead ?  I AM confused ..... All I can say is all is ONE, all is equal, yet we still bicker, and it seems we always will. Go science and philosophy .... let's figure it all out !   

Now what was that rant ? Ummm, Beer, Pot, LSD flash back, Allan Watts, Dad, Mom, Friends, Science, and ALL the rest that I AM .... 

Possible life ??? My sense of morality is to love it all, to understand it all, to do all we can do, to stop suffering for all that can feel .... within our free will capacity ....  (does the forest feel and love the sun ? ))))))) 

 Geeezzz , fix my words and math ....   

"What isn't god",  I most always ask the religious ... and my fellow atheists. 

It has been interesting for sure...

What I got to wondering as I kept pondering the point you make here is if the  philosophic is just as important as the biological.  Should we care about the purposes of each stage?  Take Kevin's post for example.  Each time I read it I can't help but think of the extremity of the ideas not just against my own personal opinions but at the same time thinking how many Americans might react to something like that.  Thinking about it can open a Pandora's Box of scenarios not just from the moral aspects of it but think if it had been an option say 100 years ago; would this world have never seen the likes of someone like Hitler or Einstein or for that matter any single person on this forum (whoa)?

But extremes aside, is there more to "life" than just the biological?  If so then I think hamby's point of human life being nothing special (paraphrasing from the "Since humans are just another life form in the same tree, I can't think of any reason to treat humans differently" point) just flew right out the window.  So I wonder, since we agree on the scientific, is the philosophical aspect of "when does life begin" important? 

My personal take: just as important as the biological.

One day, I'm going to start a betting pool in the mod forum.  I would have totally won this one.  I'm going to call it:  Guess The Fallacious Response.  Everybody chips in ten bucks, and the one who guesses the next fallacy by the selected theist wins the pool.

Anyway, before you finish reading this post, please take some time and read this article:

Does Science Take Away Wonder and Awe?

Done?

Ok.  Now you know that science doesn't, in fact, take away wonder or awe.  You also know how fulfilling it can be to take a scientific discovery and run with it because the scope of even a small insight can have enormous impact on our day to day lives.

To address your main point, the reason the scientific explanation sounds cold to you is that you've been fed (and believed) a bullshit version of human life.  There is no magic in the universe.  There is no "higher meaning."  There is no inherent sanctity of human life -- or any other life, for that matter.  However, the very act of living is amazing.  The realization that each moment I experience is a singular, unrepeatable, unimaginably brief flicker of time makes that last bite of seared tuna taste really fucking awesome!  If I never get another bite, I have done something amazing, and my existence was better for it.

(Speaking of which... tonight, I'm making a Tuna, Fennel, Avocado, and Tangerine salad with Citrus Vinaigrette.  I've wanted to try this recipe for months!)

As I've said, I have a very clear understanding of my position on abortion, and I'm very comfortable with it, regardless of political posturing.  Does this mean I'm a cold, calculating shell of a man who doesn't have any human compassion?  Of course not.  Ask anyone.  I'm a very empathetic person, and my preferred field of study -- evolutionary psychology, specializing in human sexuality -- is interesting to me precisely because I want to help other people have a healthy and true understanding of their own bodies and minds.  I'm tired of seeing my friends repeat mistakes over and over because they simply don't understand their own instincts.

Whether it's inner city violence, spouse abuse, genocide in Rwanda, or the destruction of the rain forest, there is something happening in the world that you look at and think, "That sucks, but damn... it's just part of the way the world works,"  and then you go on being a good person in spite of it.  Just because science looks with an unbiased eye at human existence, it doesn't mean that you or I or anyone else must turn into a cold, heartless person.  The true explanation that fetuses are not technically humans doesn't make pregnancy any less wonderful for a couple who's been trying to get pregnant for years.  The fact that a girl who doesn't want a baby gets an abortion doesn't make parenthood any less wonderful for those who love it.

Think of it one more way.  Suppose that scientists discovered, with as much certainty as they have about evolution or gravity, that human fetuses go through a phase where they are not only not human, they are actually chimpanzee -- in every way.  (I know it's stupid and far fetched, but run with it.)  When you have a candlelight dinner with your beloved, and you gaze longingly into each others' eyes, is the experience any less meaningful?  Of course not.  Science doesn't take away from the warmth of your life.  It just explains in true terms why it is as warm and wonderful as it is.

Any cell regardless of its function is useless on its own. It's a large combination of similar cells that make up an organism and the parts required for it to function. It's like the tree/forest analogy. So if a cell is nothing, why is a conglomeration of nothings not also nothing?

Reproduction is only one of the criteria for defining living organisms. How could two not live things suddenly turn into life?

Define "functioning." Does that include the ability to regulate bodily functions? What about sentience? What about self-awareness? You've put yourself on a slippery slope with your poorly defined terms here. If the ability to reason is what you are referring to, then 2 year olds are not necessarily life. Nor are those with mental retardation. What's the crucial element then?

I think Mike's using the term "life" as the beginning of a separate individual organism--not "life" as in how cells are defined as life. I assure you that Mike is quite aware of cellular functioning since he specializes in a field that deals with life on that level. (Don't remember exactly what it's called--something about cell membranes and stuff.)