BTW JeanPaulBob, I'm not really asking about biology here; I'm asking about the foundations of why you think the life of a zygote is worth as much as the life of an adult. And merely stating that the would-be adult and the zygote have the same genotype isn't a satisfying answer. And citing the survival needs of the zygote isn't a satisfying answer. There are some drastic practical differences in form and function between zygote and infant, and I'd like to know why those differences shouldn't matter, because there's tons of evidence (particularly from neuroscience) indicating that they *do* matter .

Ok; so why do you buy into the idea that "I" was a "complete human being" at the point of genotype establishment? What are the foundations of that assertion? What evidence would you cite?

Regardless of definitions of "human being", "person", and so on: I don't understand what you're talking about. What "horror"? Please describe the nature of suffering that results (potentially or actually) from the destruction of a blastocyst. Or if that's not possible, please explain why you think the horror you mention has some actual referent outside your imagination.

I'm asking because I don't merely want to verbally tear into right-to-lifers; I honestly want to understand where you're coming from, and so far your position doesn't make sense to me, and I don't even see how it makes sense to you.

Also: I recognize that you don't agree with my position (briefly: "components of brain clearly generate components of the mind; therefore 'no brain' strongly indicates 'no person', for some definition of 'person' that includes the existence of emotions, impulses, perceptions and the like"). But do you at least understand how it makes sense to me?

Or perhaps that was kind of your point? I.e. that the original idea of 'soul' grew out of a culture that knew practically nothing about biology, so we should expect the 'soul injection' argument to make little sense. It would be like trying to graft ancient peoples' beliefs involving the Greek god Helios onto what astrophysicists are now able to tell us about the solar system.

Ok; if one is into mythology I guess that's interesting, but I don't see how it's relevant to the topic being discussed.

I was not aware of the supposed equivalence to blood. :-)

I don't know the answer; sorry. I Am Not A Developmental Biologist.

Sorry; did you mean to ask, "When does *DNA* happen?" If so then I don't understand your question. I do recognize fertilization as the point where my present-day genotype was established, and since I have no twin, I understand that my genotype is unique. I also understand that my genotype resulted from a kind of fusion of chromosomes from my parents' gametes.

Were you just checking to make sure of all that? :-) Was there some point you wanted to make?

Be careful with the terms! A fetus is *never* involved in *embryonic* stem cell research. Instead, blastocysts are employed.

So, for a moment let's set aside uses of the term "human", since different people want to use different definitions and that's confusing.

Are you saying that a sperm cell should not be regarded as having rights because it's not able to grow into an adult without coming into contact with an egg?

In that case, it seems you have a similar problem with blastocysts: *they* don't grow into later-state embryos (let alone adults) if they fail to bind to the uterine wall (and that failure naturally happens quite often). What is it about the difference between:

• the sperm's dependence on the egg and
• the blastocyst's dependence on the uterus

that it causes you to see one as "deserving rights" and not the other?

If you want the definition of the term "human being" to include blastocysts, would you also want gametes included?

If not: why not? Is it merely that each sperm and each egg only has half the genetic material of the organism that produced it? But in that case why didn't you take the position that a human being should be protected even if it only has half the genes of more "developed" human beings? [Note, I normally do not regard sperm or egg cells as human beings.]

If so: how about the cells that produced the gametes? How about skin cells? If someone gives you a paper cut, have they committed genocide?

Because without neurons, there's none of the kind of information processing that makes a person: no concepts, no dreams, no emotion, no "instinct", no impulses, no more capacity for suffering---or for anything else---than a colony of bacteria, no perception of any kind---nothing.

(At this point some people like to say that there is *potential* for the blastocyst to grow into something else that has the biological machinery for those things. And while that is true it is somehow not compelling. Does each *potential* life have an *inalienable right* to be made *actual*? I don't know of any reasonable way to answer "yes" to that question.)

For the purpose of deciding whether a given entity has some inalienable universal right, we have to draw the line somewhere. Maybe someday we *will* recognize each bacterium as deserving said rights, and presumably around that time it would be consistent to do the same with each cell in a blastocyst. Until then, I think it's ok to say that "someone" isn't human if "they" don't have at least one iota of the hardware that makes it possible for the rest of us to exhibit the things that make us human.

No, it's not ok. The difference is that there's an *actual* person there (and not just a *potential* person). Not only does that entity have the *capacity* for all those wonderful mental activities, *it's actually doing many of them every minute of every day*, even while sleeping. (Though we tend not to notice the latter as much. But talk to your local neuroscientist who specializes in sleep studdies; it's fascinating stuff.) Besides: your hypothetical someone also probably wanted to go on living. That's another thing that sets him/her apart from the blastocyst out of which that person grew.

I don't know. There may be a time (say, when we really understand the nature of consciousness) when our understanding permits us to apply more fine-grained rules. For now, for practical purposes, all of us demand *some* kind of boundary (whether stark or gradual, early or late) between "deserving rights" and "not deserving rights". So for now I could be content to say an embryo "deserves full rights" as soon as it has a brain (even though a housefly might have a larger and more complex brain). I'm totally open to reevaluating that stance however.

I suppose that depends on what you think "human being" means and what you think "person" means. :-)

That's basically correct. Would you say that you don't? Or perhaps you would pretend not to by assuming a definition of "body" that excludes sperm and egg cells but not zygotes? If so, what is the basis for that exclusion?

Won't somebody please think of the gametes? :-)

(It could be argued that life never "begins" (at least, not for any individual "human being"): life can also be seen as a continuum of ever-shuffling genes where a zygote is just a *continuation* of sperm and egg, which in turn are continuations of the cells that created them, and so on, backward in time to the first replicating molecule billions of years ago.)

While technically true, the term "embryo" can be misleading: it could lead some to think that the thing being destroyed is something close to a fetus---i.e., something with a central nervous system and a beating heart. But typically, "Embryonic stem cell research" only involves the destruction of a blastocyst. We're talking about a tiny cluster of cells that has *no neurons*. (If left to grow into a late-stage embryo then some of the cells in a blastocyst will have been the *distant ancestors* of the first neurons.)

And the anti-ESCR crowd objects to said destruction because...well it's not clear. I gather that some of them think a "soul" is injected into a zygote at the moment of its formation. (Of course, the meaning of that sentence hinges on what you think a "soul" is, and I rarely get a satisfactory definition out of religious types.)

But if there is such a thing as a human soul---loosely defined here as the mind of a person---then findings in neuroscience seem to suggest that a human soul is something generated by a human brain. In that case a common housefly would have greater capacity to bear a soul than a blastocyst, because at least a housefly has a brain!

So while I recognize that the anti-ESCR crowd has some deep emotional feelings about this, I also feel that the respect paid to them by policy-makers was not earned legitimately. How could it have been? The foundation of their argument is superstition.

It's a solution. But it may not be a terribly satisfying one for devotees of any particular mythology: it implies that the architect could be infinitely lazy (and effectively indifferent to suffering)---almost as if the architect *isn't there at all*. Consider that modern Darwinian evolution explains the origin of all known forms of life. That means that, in order for complex life to come into existence, divine intervention is not required. It also means that if divine intervention *did* happen, then it happened in such a way as to be indistinguishable from natural phenomena.

To people who were brought up to believe in the resurrection of Jesus or the flying horse of Mohammed, that can be a hard pill to swallow, because if a *seemingly* miraculous phenomenon (like the existence a complex organism) is actually best explained through natural events *without* conscious design, then it means that the god that such people believe in---i.e., a god who performs miracles in order to make desirable things happen---doesn't *necessarily* exist. So then a religious person is faced with the idea that there might still be *a* god, but probably not the kind that performs magic tricks and talks to people.

And so if you've been praying to a personal, miracle-performing god since childhood, then the mere *idea* of a workable, rational scientific explanation for some of the biggest "miracles" (without an actual *understanding* of said explanation) could be potentially more upsetting than a death threat against a close relative. And so a natural response is denial, because otherwise you would be afraid of losing the feeling of being connected to and cared for by the universe.

(I'm not saying the religious folk are correct; I'm just saying that I consider this to be one plausible explanation for why they have a hard time with it; why they often don't even learn what Darwinian evolution is; etc.)

Another explanation probably has to do with the belief that one's personal brand of mythology was, to paraphrase Carl Sagan, dictated by the creative force of the universe to an **unerring stenographer**; and that any statement contrary to the mythology is just wrong by definition. (I still don't know why anyone would hold to that, and I would love to read more about any science on the topic.)

12. Bill Adama finally returning to his first love: teaching calculus.