If you believe that feeling bad or worrying long enough will change a past or future event, then you are residing on another planet with a different reality system.

William James

If asked, they would say that they're glad to have existed [...]

There is an interesting question here: What does it mean to say that I'm glad to have been born? Or rather, what does it mean to say that I prefer to have been born?

The alternative scenario in which I was never born is strictly counterfactual. I can only have a revealed preference for having been born if I use a timeless/updateless decision theory. In order to determine my preference you'd need to perform an experiment like the following:

• Omega approaches me and offers me $100. It tells me that it had an opportunity to prevent my birth, and it would have prevented my birth if and only if it had predicted that I would accept the $100. It is a good predictor. Do I take the $100?

Without thinking about such an experiment, it's not clear what my preference is. More significantly, when 30% of American adolescents in 1930 wish they had never been born, it is not clear exactly what they mean.

Now if you know I'm an altruist, then the problem is simpler: I prefer to have been born insofar as I prefer any arbitrary person to have been born, and this preference can be detected with the thought experiment described in the OP.

... unless I'm a preference utilitarian, in which case I prefer an arbitrary person to have been born only if they prefer to have been born.

It's different because (1) I'm not hurting other people, only myself, and (2) I'm not depriving the world of my victim's potential contributions as a free person.

I don't actually care about the avoidance of torture as a terminal moral value.

It currently says this:

I naturally take a stance against abortion. It's easy to see why: a woman's freedom is less important than another human's right to live.

So, you are a pro-life person who values life over freedom, yah?

painless euthenasia is a parental right up until the child is old enough to object IMO.

What constitutes an objection? Does crying loudly count? And what happens if they can object but then lose the ability to object (due to say brain injury)?

Fixed, thanks.

Um, no it's not. It currently says:

a woman's freedom is less more important than another human's right to live.

Abortion is one of the most politically-charged debates in the world today - possibly the most politically charged

It may be in the US and many religious countries, but it isn't a big issue in France - I haven't heard of any politician talk about abortion here, and it's not subject to much debate in the media either. My wife says "Yes, there is some debate, some hospitals are even refusing to perform abortions, you just don't pay attention because you're a man", so OK, it may be a bit of an issue, but not a very polarizing one.

(And of course, it's not a big issue in China, where abortion is sometimes encouraged by the state.)

In some sense, they are contradictory. Or at least mutually opposed.

That is, if you and I uncovered the Visitors' plan to forcibly prevent humans from engaging in any activity that lowers our expected lifespans, you would (I infer) endorse that plan, and I might not. Depending on the situation, I might even act to disrupt that plan, and you might act to stop me.

Of course, that's not going to happen. But you might vote and donate money to support criminalizing unhealthy practices (because doing so buys life at the cost of mere freedom) while I vote/donate to support legalizing some of them (because sometimes I value freedom more than life).

In any case, I'm happy to move on in a pragmatic sense, but I wanted to be clear that there really is a point of pragmatic opposition here; this isn't an entirely academic disagreement.

I reject treating human life, or preservation of the human life, as a "terminal goal" that outweighs the "intermediate goal" of human freedom.

More generally, I don't believe there's any simple relationship between my valuation of the two that can be expressed without reference to other parameters.

That is, there are many contexts in which I endorse trading actual human life for human freedom. Still more so, potential human life. And there are many contexts in which I endorse trading human freedom for human life.

Seeing this makes me happy because I had a similar revelation a few years ago and it always makes me mad to see people use the glaringly bad justification for being pro-choice which you've overcome. On the other hand, after thinking about the matter quite a bit I still am pro-choice. You say:

On the other hand, as little as it is, it still represents a human life

I think the key word is "represents".

A lot of bad reasoning seems to come from proving a controversial idea can be fit into a category of things that are mostly bad, and then concluding that the controversial idea, too, must be mostly bad.

For example, some people are opposed to a project to genetically engineer diseases like cystic fibrosis out of the human genome, because that's a form of "eugenics". I think this is supposed to cash out as saying that the CF project shares some surface features with what the Nazis did and what those American Southerners who tried to force-sterilize black people did, and those two things are definitely bad, so the CF project must also be bad.

The counterargument is that the features it shares with the Nazi project and the Southern project are not the features that made those two programs bad. Those two programs were bad because they involved hurting people, either through death or through force-sterilization, without their consent. The CF elimination project hopefully would be voluntary and would not damage the people involved. Therefore, although it shares some similarities with the Nazi project and the Southern project (it's about genetics, it's intended to improve the species, etc), those aren't relevant to this moral question and the argument "But it's eugenics" is flawed.

(If you haven't read the 37 Ways Words Can Be Wrong sequence, I suggest that now. Think of a person taking a blue egg that contains vanadium, pointing to a bin full of blue eggs that contain palladium, and saying "But this is a blegg, and we all know bleggs contain palladium!" Well, no.)

The "human life" issue strikes me as very similar. "Taking a human life" is a large category mostly full of bad things. It contains things like stabbing a teenager with a knife, poisoning a senator, strangling an old person in a nursing home, starving a toddler, et cetera. All of these are really bad. They're really bad for various reasons including that they cause the person pain, that they disrupt society, that they violate the person's preference not to be killed, et cetera.

Abortion possibly does fit into the category of "taking a human life." But although it shares the surface features of that category, it isn't clear whether or not it shares the interesting moral feature which is exactly what the whole argument is about. Killing you or me is bad because we understand death and have preferences against it and don't want to die. Whether or not killing a fetus is bad depends on whether or not the fetus also satisfies those conditions - not on whether from a certain angle the problem looks like other cases that satisfy those conditions.

The question isn't whether or not we want to stick the fetus into an artificial category called "human", it's whether it has the specific features that make that category relevant to this particular problem in the first place.

See Leaky Generalizations and Replace The Symbol With The Substance