I took it and threw in on the ground!

We both agreed to the statement that killing human beings is morally bad. Now, the definition of a human being came up.

As a general guideline, if you're arguing morality, and you find yourself arguing definitions, you've taken a wrong turn.

Ethical arguments that hinge on definitions are almost always the result of trying to set the threshold for some simple, hard-and-fast binary "yes/no" rule.

As of an example with an egg I have an easy answer. The probability of an egg becoming a human is much much lower without fertilization.

I don't think you're answering the question DanielLC wanted to ask. I think the question is more like this: If you refrain from fertilizing an egg (say, in some random woman walking by on the street), isn't that as bad as committing murder?

Re: the violent dictator... as I said initially: "If 1000 more lives are saved, it's even an emotionally compelling argument."

Killing a Bad Person to save a thousand Innocent People is a relatively easy emotional equation, and that's as true of me as it is for you.

As for the point where we disagree... I'm not certain we do disagree, actually.

If you're asking me about a particular human whose fate is singularly brought to my attention, does it live or die, I almost undoubtedly let it live as long as that doesn't cost very much to me or anyone I care about, or even if it does if the human is someone I happen know and like.

I don't think we disagree on this point.

But if you ask me whether "less humans" is better or worse in general, which is what I thought you were asking about, I understand that to be a different question.

I am, right this moment, not raising a child. I'm not even siring one to be raised by others. In fact, I haven't done either of those things in my life (as far as I know) and am very unlikely to in the future. I know that this results in fewer humans compared to a lifestyle of siring as many children as possible.

If "less humans => worse", it follows that I'm choosing to make the world worse.

As I've said, I don't believe that, so that doesn't bother me. You seem to be claiming that you do believe that (as you say, without the need for any additional knowledge about the situation), so it seems to follow that you believe I'm making the world worse and that I should be siring as many children as possible.

Do you in fact believe that?

My guess is that you don't, and that we don't actually disagree as much as you seem to think we do.

I think the appearance of disagreement is in part because you're switching the question around (from "is fewer humans worse?" to "would I let a human die, given a salient choice?") in mid-conversation, and comparing my answer to the first question to your answer to the second question.

That might be a deliberate "bait and switch", but my intuition is that you're doing that because the question switches around in your own head as you think about it. Of course I don't know for sure, but that's a pretty common thing people do when thinking about emotionally difficult questions.

It is clearly correlated, since the probability of the fetus' survival increases as it develops, as the evilness of killing does. However I don't think the probability of becoming a fully functional human is what determines the moral condemnation of killing. To illustrate my intuition, consider:

• Babies are clearly not fully functional humans. I doubt we can acknowledge full functionality earlier than in age when humans are capable of reproduction. In Sierra Leone a newborn baby has a 26% chance of dying before age of five, and probably further non-trivial chances of dying until puberty. If the probability argument holds, killing a one year old child in Sierra Leone would be about 30% less evil than killing an adult. Yet many people hold that killing children is actually worse than killing adults.

• Imagine a world where after conception the embryo had almost 100% probability of survival until adulthood. Would that mean that killing a morula in such hypothetical world would equal a full-fledged murder?

Do we accept the view that "less human beings => worse"?

I can't speak for anyone else, but I don't accept this view. For example, I can easily imagine a future with N humans that I would happily choose over a different future with 2N humans, or 2^N humans.

In other words, there are many aspects of the future that I consider more important than how many human beings it holds.

If not, then why not kill people on sight?

You seem to be suggesting that the only reason not to kill people is because I want to maximize the number of humans in the world, so if I don't want that it follows that I must have no reason not to kill people. That seems pretty bizarre to me.

Anyway, I suspect the primary reason I don't kill people is squeamishness. Other reasons include fear of punishment and the belief that I can't reliably predict the consequences of them dying, and in some cases the belief that most likely consequences of them dying are bad ones.

I'd think better of myself if that last one were the primary reason, but I'm fairly certain it isn't.

The only alternatives are "less human beings => better" and "less human beings => indifferent".

And also "less human beings => better or worse, it depends on other things."

Do you want me not to judge single separated action but considering all the alternatives and choosing the best one?

I don't think anyone can consider all the alternatives, but yes, I'd certainly recommend choosing the best of the alternatives you're able to consider. I wouldn't have thought this controversial?

I fail to see any further consequences of an action of "terminating a pregnancy" than "the pregnancy is terminated".

I suspect I don't understand what you mean to express, here. Can you contrast this with an action for which you are able to see downstream consequences?

Is killing a human more bad than creating one is good? If not, everything else is irrelevant.

What exactly constitutes "becoming a human", or "killing" for that matter? An egg has a high chance of becoming a human if it's fertilized. Would refraining from fertilizing it be killing?

On the other hand, little if any of you is actually made of the original fetus. Does that mean that the fetus itself won't become a person? It's mostly food and water that becomes them.

I thought this is what we just resolved! The fetus only has that desire if he or she grows to be an adult!

Let's postulate a child in world A. World A never existed, because in world B, the real world, I destroyed the spermatozoon that fertilized that child. Another spermatozoon takes its place, and a different child was born. Did I commit murder? I hardly think so, even though there is a potential child that was never born, that had it been born it would have wished me preserve the conditions that allowed its birth.

If I did commit murder, then I must also have caused a death in World A, by preventing (through inaction) the birth of the child that could only have existed in World B.

The hypothetical entities that do not yet exist do not get to clamor for their own existence!

Here's where I think my argumentation is flaved. I'd definitely not kill a coma patient (not fully human being since not thinking) whose chances of becoming a human are 10% but I'd definitely kill a fetus (also not thinking and not living on his own), whose chances of becoming a human being are greater than 10%.

This will sound horrible and get me downvoted. But not all human lives are worth exactly the same.

It would be wrong for me to kill an adult amnesia patient with no hope of recovery but I'd consider it less wrong than killing the same person sans amnesia.

When you kill the 10% chance of awaking patient you also kill all the experiences he has already had as well as the ones he will have. When you kill the 10% chance fetus you just kill the ones he will have.

I think the "will have" in both cases is not certain to happen due to other reasosn. The has had bit is certain.

Here's where I think my argumentation is flaved. I'd definitely not kill a coma patient (not fully human being since not thinking) whose chances of becoming a human are 10% but I'd definitely kill a fetus (also not thinking and not living on his own), whose chances of becoming a human being are greater than 10%.

So is it ok to judge our action by considering how big percentage of a human being are we switching off? It seems logical, but the consequences are strange.

Check your utility function. For any given moral dilemma, the answer is always in your utility function. Or in your preference structure to be pedantic (i.e., utility functions are certain types of preference structures. Your preference structure may or may not be a utility function.)

The abortion debate is largely one big example of a disguised query. Everyone agrees that killing humans unecessarily is wrong, then they argue over whether a fetus is a human. But all of the normativity is built into this magical word, "human." Both sides are asking "is a fetus human?" and this is the WRONG question to ask. The right question is "how much do we value a fetus?"

Furthemore, there's no reason, a priori, to assume that all of the value of a fetus/baby comes at childbirth or at conception. Looking for a point in time where something discontinuous happens to the fetus in order to determine when it obtains all of it's value needs justification in itself. It assumes away the possibility of a continuously increasing value of the fetus (in time). This may or may not be a safe assumption, but in order to really know, you need to discover your own preferences. Personally, I think it's more likely to be a (relatively) continuous function in between conception and childbirth with discontinuous jumps at those two points. There is something special about both conception and childbirth that induces a sharp increase in the value of the fetus, but there's a slower, steadier increase along the way from conception to childbirth as well. There may be a few more discontinuities as well, e.g. when the heart starts beating or the brain begins to control the body.

As for the difference between the fetus and a coma patient, consider biting the bullet that you just do value coma patients more than fetuses. There's nothing inherently wrong with that. Someone else might exclaim that your morally depraved, but that's what their utility function says, not yours.